Store live photos as their image and their video (closes #107)

A live photo, which Ente stores as one ZIP, is unpacked as it downloads
into its image and its video, each `<fileID>.<ext>` with its extension
from the ZIP, beside `<fileID>.livephoto.json`, which names the two.
Both are checked against the recorded hash and renamed into place only
when both are complete. The backup and the content cache count a live
photo as stored only with both files, album folders link both,
`quak get` writes both, and the content result gives the video as
`videoPath`. A ZIP an earlier version stored is replaced.

Model: opus-5-5

.dockerignore

@@ -1,6 +1,6 @@
 # Mirrors .gitignore, with one deliberate exception: .gitignore itself stays
 # in the build context, because prettier 3 reads it as a default ignore file
-# and dropping it would change what `make fmt-check` sees inside the image.
+# and dropping it would change what the lint phase's prettier check sees.
 
 # VCS
 .git

Dockerfile

@@ -1,28 +1,69 @@
-# Test and build image: the suite, then the compile.
+# Lint phase. The linters are invoked directly rather than through `make
+# lint` or `script/lint`, which are themselves a docker build and would
+# recurse into a daemon that does not exist in a build step.
 #
-# Linting deliberately does not happen here. `script/lint` is a build of
-# Dockerfile.lint, and `script/check` calls `script/lint`, so running
-# `make check` in this image would mean running `docker build` inside a
-# container. Lint runs exactly once, in Dockerfile.lint; script/cibuild
-# builds that first and this second.
 # node 22.22.0 on Alpine 3.23.3 (node:22-alpine), 2026-08-09
-FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS check
+FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS lint
+
 WORKDIR /app
 
 COPY script/ script/
 COPY package.json yarn.lock ./
 RUN script/bootstrap
+
 COPY . .
 
-# CHECK_EPOCH is a cache buster: without it Docker serves the test layer from
-# cache on an unchanged tree, the suite never executes, and the build still
-# exits 0. The guard makes an absent argument a hard failure — an unset ARG
-# is the empty string, which is a perfectly stable cache key, so a plain
-# `docker build .` would otherwise still get the false green. Fail closed.
-ARG CHECK_EPOCH
-RUN [ -n "$CHECK_EPOCH" ] || exit 1
-RUN make test
+RUN yarn run eslint .
+RUN yarn run prettier --check .
+
+# Test phase, same shape and for the same reason. The suite runs without
+# verbose output first and is rerun verbosely only if it fails; the timeout
+# catches a hung test.
+#
+# node 22.22.0 on Alpine 3.23.3 (node:22-alpine), 2026-08-09
+FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS test
+
+WORKDIR /app
+
+COPY script/ script/
+COPY package.json yarn.lock ./
+RUN script/bootstrap
+
+COPY . .
+
+# Unlike the template, the suite runs as the image's non-root `node` user:
+# root ignores directory permissions, so the tests of a destination that is
+# not writable would otherwise fail. vitest writes into /app.
+RUN chown -R node:node /app
+USER node
+
+RUN timeout 90 yarn run vitest run --reporter=dot || \
+    { echo "--- Rerunning with verbose for details ---"; \
+      timeout 90 yarn run vitest run --reporter=verbose; exit 1; }
+
+# Build stage, and the last stage: a plain `docker build .` names no target
+# and so builds this one. Nothing is wanted from the two phases above; the
+# copies are what make BuildKit build them first, so this image cannot be
+# produced unless lint and test passed. A stage appended after this one
+# would drop all three out of a plain build.
+#
+# node 22.22.0 on Alpine 3.23.3 (node:22-alpine), 2026-08-09
+FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34
+
+WORKDIR /app
+
+COPY --from=lint /app/package.json /dev/null
+COPY --from=test /app/package.json /dev/null
+
+COPY script/ script/
+COPY package.json yarn.lock ./
+RUN script/bootstrap
+
+COPY . .
+
+# The version is computed on the host and passed in, because
+# .dockerignore excludes .git.
+ARG VERSION=dev
+LABEL org.opencontainers.image.version="${VERSION}"
 
-ARG CHECK_EPOCH
-RUN [ -n "$CHECK_EPOCH" ] || exit 1
 RUN make build

Dockerfile.lint

@@ -1,35 +0,0 @@
-# Lint image: every lint run happens here, and nowhere else. The repo is
-# COPYed into a digest-pinned image and the linters run as build steps, so a
-# successful build IS a clean lint. `script/lint` does nothing but build this
-# file, which also works where the docker daemon is remote and bind mounts are
-# impossible. Nothing that runs inside a container may call `script/lint`:
-# that is why Dockerfile no longer runs `make check`.
-# node 22.22.0 on Alpine 3.23.3 (node:22-alpine), 2026-08-09
-FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS lint
-WORKDIR /app
-
-# Manifests before sources, so the dependency install layer stays cached
-# until package.json or yarn.lock changes. script/bootstrap ends in
-# `yarn install --frozen-lockfile`; the lint steps below are deliberately
-# not cached.
-COPY script/ script/
-COPY package.json yarn.lock ./
-RUN script/bootstrap
-
-COPY . .
-
-# LINT_EPOCH is a cache buster, with the same fail-closed contract as
-# CHECK_EPOCH in Dockerfile. No lint cache is wanted: on an unchanged tree
-# Docker serves the linter layers in well under a second, having linted
-# nothing, and the build still exits 0. The guard makes an absent argument a
-# hard failure — an unset ARG is the empty string, which is a perfectly
-# stable cache key, so a plain `docker build -f Dockerfile.lint .` would
-# otherwise get exactly that false green. Every layer below this one is a
-# child of the guard, so a fresh epoch forces all of them to execute.
-ARG LINT_EPOCH
-RUN [ -n "$LINT_EPOCH" ] || exit 1
-
-# The linters are invoked directly rather than through `make lint`, because
-# `make lint` is the build of this file.
-RUN yarn run eslint .
-RUN yarn run prettier --check .

README.md

@@ -73,7 +73,7 @@ if (photo) {
     console.log(`original at ${path}`);
 }
 
-lib.close();
+await lib.close();
 ```
 
 The lower-level `Client` (login, session serialization, and the raw
@@ -97,20 +97,18 @@ alpine. We provide:
 - `script/build` — compile the TypeScript sources into `dist/`, then verify that
   the entrypoints `package.json` declares (`main`, `types`, `bin`) are among the
   files the compiler wrote, and make the CLI executable (our own extension)
-- `script/test` — run the test suite (vitest, hard-capped at 30s where `timeout`
-  is available, verbose rerun on failure)
-- `script/lint` — run eslint and a prettier check, by building
-  `Dockerfile.lint`; requires docker (see Linting below)
+- `script/test` — run the test suite, by building the `test` phase of the
+  `Dockerfile` (vitest, 90s timeout, verbose rerun on failure); requires docker
+- `script/lint` — run eslint and a prettier check, by building the `lint` phase
+  of the `Dockerfile`; requires docker (see Linting and testing below)
 - `script/fmt` — format all files with prettier (writes)
 - `script/fmt-check` — check formatting on the host (read-only); standalone, and
   not called by `script/check` or `script/precommit`, because `script/lint`
-  already checks formatting in the container (see Linting below)
+  already checks formatting in the container
 - `script/check` — run all checks: `test`, `lint` (our own extension)
-- `script/docker` — build the test and build image, tagged via
-  `script/projectname`
-- `script/cibuild` — cd to the repo root and build both images (what CI runs):
-  `script/lint` first, then the `Dockerfile` image, which runs `make test` and
-  `make build`
+- `script/docker` — build the image, tagged via `script/projectname`
+- `script/cibuild` — build the image (what CI runs); its last stage depends on
+  the `lint` and `test` phases, so this one build lints, tests and compiles
 - `script/precommit` — run by the git pre-commit hook (our own extension); runs
   `script/lint`, which checks both lint and formatting, but deliberately not the
   tests, so the TDD red-phase commit can land
@@ -119,50 +117,32 @@ alpine. We provide:
 
 `make hooks` installs the pre-commit hook that runs `script/precommit`.
 
-### Linting
+### Linting and testing
 
-Linting runs in a container, one way, everywhere. `script/lint` builds
-`Dockerfile.lint`, which copies the repo into a digest-pinned node image and
-runs eslint and prettier as build steps, so a successful build is a clean lint.
-There is no host lint path: docker is required to lint, and that also works
-where the docker daemon is remote and bind mounts are impossible.
+Linting and testing are phases of the `Dockerfile`. The `lint` phase copies the
+repo into a digest-pinned node image and runs eslint and `prettier --check .`;
+the `test` phase does the same with the suite. `script/lint` and `script/test`
+each build one phase with `docker build --no-cache --target <phase>`. There is
+no host lint or test path: docker is required, and that also works where the
+docker daemon is remote and bind mounts are impossible.
 
-The formatting check is part of that, not a step beside it. `script/check` and
-`script/precommit` therefore call `script/lint` and stop; neither calls
-`script/fmt-check` as well, which would run prettier a second time over the same
-tree for the same verdict — and the weaker of the two, since the host's prettier
-is whatever the working tree has installed. So `make check` and the pre-commit
-hook both still fail on a badly formatted tree, and prettier runs exactly once
-in each. `test/packaging/lint-once.test.ts` asserts that count by walking the
-invocation graph, so a second pass cannot creep back in unnoticed.
+The last stage of the `Dockerfile` compiles the package, and it copies a file
+from each phase, so it cannot be built unless lint and the tests pass. That is
+why `script/cibuild` is a single `docker build`: it runs lint and the tests once
+each and then compiles.
 
+Every `docker build` in `script/` passes `--no-cache`. On an unchanged tree
+Docker would otherwise serve the lint and test steps from cache, nothing would
+run, and the build would still exit 0.
+
+The formatting check is part of the `lint` phase, not a step beside it, so
+`script/check` and `script/precommit` do not call `script/fmt-check` as well;
+that would run prettier a second time over the same tree for the same verdict.
 `script/fmt-check` remains as a standalone entrypoint for asking the formatting
-question on its own, without docker and without the rest of lint. Its verdict
-cannot drift from the container's: prettier is pinned to an exact version,
-installed from `yarn.lock` under `--frozen-lockfile` in both places, and reads
-`.gitignore` as its default ignore file — which is why `.dockerignore`
-deliberately keeps `.gitignore` in the build context.
-
-Lint happens in exactly one place, which constrains the rest of the build.
-`script/check` calls `script/lint`, so `make check` cannot run inside a
-container without asking for docker inside docker. The image built from
-`Dockerfile` therefore runs `make test` and `make build` and does not lint;
-`script/cibuild` builds `Dockerfile.lint` first and that image second, so CI
-gets both verdicts.
-
-### Build epochs
-
-`script/lint` passes `--build-arg LINT_EPOCH="$(date +%s)"`, and `script/docker`
-and `script/cibuild` pass `--build-arg CHECK_EPOCH="$(date +%s)"`. Both
-Dockerfiles refuse to build without their argument. This is deliberate: on an
-unchanged tree Docker would otherwise serve the linter and test layers from
-cache, so nothing would run and the build would still exit 0 — a lint build over
-an untouched tree returns success in well under a second, having linted nothing.
-A changing epoch invalidates every layer below the guard on every invocation
-while leaving the dependency layers above them cached, and the missing-argument
-guard means a bare `docker build .` fails loudly instead of quietly reporting a
-green it did not earn: an unset build argument is the empty string, which is a
-perfectly stable cache key.
+question on the host. Its verdict matches the container's: prettier is pinned to
+an exact version, installed from `yarn.lock` under `--frozen-lockfile` in both
+places, and reads `.gitignore` as its default ignore file — which is why
+`.dockerignore` keeps `.gitignore` in the build context.
 
 ## Rationale
 
@@ -197,10 +177,9 @@ All work on quak is test-driven. No exceptions.
 3. Subsequent commits add the implementation and any refactors needed to make
    the tests pass.
 4. A feature branch can only be merged into `main` when `make check` is green.
-   `main` is always green. CI runs `script/cibuild`, which lints via
-   `Dockerfile.lint` and then runs `make test` and `make build` in the
-   `Dockerfile` image, so neither a red branch nor one that does not compile can
-   pass CI.
+   `main` is always green. CI runs `script/cibuild`, which builds the
+   `Dockerfile`: its `lint` and `test` phases, then the compile, so neither a
+   red branch nor one that does not compile can pass CI.
 5. Tests are the canonical API documentation for this library. Every test file
    is commented thoroughly enough that a reader who has never seen quak can
    learn how to use it from the tests alone. Comments explain why a behavior
@@ -217,7 +196,7 @@ All work on quak is test-driven. No exceptions.
    runs `script/lint` — eslint and the prettier check, in the container — but
    not the tests, and so not the full `make check`. This is deliberate so the
    TDD red-phase commit (failing tests, no implementation yet) can land. The
-   suite runs as part of the image build, which is what CI executes via
+   `test` phase is part of the image build, which is what CI executes via
    `script/cibuild`, so a red branch still cannot reach `main`.
 
 ## Design
@@ -235,18 +214,29 @@ quak/
         auth/           login flow (SRP + email OTP + TOTP), key unwrap
         model/          decrypted Collection, File, Metadata types + decrypt fns
         download/       streaming file/thumbnail download + decryption
+        library/        the cache-backed Library: metadata store, read
+                        surface, records, content cache, precache, ML data
+                        and search, request pools
         backup.ts       resilient full-account backup with dedup
+        metadata-backup.ts
+                        backup-metadata: all decrypted metadata as JSON
+        mldata-fetch.ts fetch + decrypt per-file ML data
+        filename.ts     safe file names from server metadata
         errors.ts       error types shared across layers
         retry.ts        retry classifier + exponential backoff with jitter
         thumbnails.ts   detect + regenerate missing thumbnails
         client.ts       high-level Client class assembled from the above
+        cli-commands.ts the CLI's commands as functions returning exit codes
+        cli-output.ts   how the CLI prints a file's title and time
+        cli-read.ts     fresh reads for the CLI's read commands
+        cli-run.ts      run a command, print its error, exit with its code
+        cli-session.ts  read the saved session file back into a Client
         index.ts        public library exports
     bin/
         quak.ts         CLI entrypoint (commander.js)
     test/               unit + integration tests (vitest)
     Makefile
-    Dockerfile          test suite and compile
-    Dockerfile.lint     eslint and prettier, as build steps
+    Dockerfile          lint phase, test phase, compile
     package.json
     tsconfig.json
 ```
@@ -318,11 +308,13 @@ Endpoints used:
   encrypted token plus key attributes.
 - `POST /users/ott` and `POST /users/verify-email`: email OTP fallback path.
 - `POST /users/two-factor/verify`: TOTP second factor.
+- `POST /users/logout`: end the calling token's session (`quak logout`).
 - `GET /collections/v2?sinceTime=<usec>`: list collections changed since
   microsecond timestamp; pass 0 for a full enumeration.
 - `GET /collections/v2/diff?collectionID=<id>&sinceTime=<usec>`: list files in a
   collection; paginate while `hasMore` is true.
 - `GET https://files.ente.io/?fileID=<id>`: download encrypted file bytes.
+- `POST /files/data/fetch`: fetch encrypted ML data for a batch of files.
 - `POST /files/upload-url`: mint a presigned upload URL (for thumbnail repair).
 - `PUT /files/thumbnail`: register an uploaded thumbnail's object key.
 
@@ -362,35 +354,41 @@ and a half seconds of waiting. `sleep` and `random` are injectable through the
 same option, which is how the test suite exercises the whole policy without
 waiting.
 
-Two deadlines, applied with `AbortSignal.timeout()` and renewed for each
-attempt:
+Two deadlines, renewed for each attempt:
 
-| Option              | Default  | Applies to                                  |
-| ------------------- | -------- | ------------------------------------------- |
-| `requestTimeoutMs`  | `30000`  | `getJSON`, `postJSON`, `putJSON`, `putFile` |
-| `downloadTimeoutMs` | `600000` | file and thumbnail body transfers           |
+| Option              | Default | Applies to                                  | Kind                                  |
+| ------------------- | ------- | ------------------------------------------- | ------------------------------------- |
+| `requestTimeoutMs`  | `30000` | `getJSON`, `postJSON`, `putJSON`, `putFile` | the whole request                     |
+| `downloadTimeoutMs` | `60000` | file and thumbnail downloads                | idle: no bytes received for this long |
 
-They are separate because one number cannot serve both: a value short enough to
-keep a hung API call from stalling a backup would cancel a legitimate
-multi-gigabyte download. The download deadline covers the body, not just the
-headers — `getFileStream` returns as soon as headers arrive, so a deadline that
-only guarded the initial request would leave the same hang one layer down.
+They are different kinds because a download's length depends on the file and the
+link: a whole-transfer deadline short enough to catch a hung connection would
+cancel a large video on a slow link that is still making progress. The download
+deadline restarts every time bytes arrive, so a slow download runs as long as it
+keeps moving, and one that stalls is aborted after 60 seconds of silence. It
+covers the wait for the headers and the body — `getFileStream` returns as soon
+as headers arrive, so a deadline that only guarded the initial request would
+leave the same hang one layer down. There is no limit on the total length of a
+download.
 
 **Non-idempotent requests are not blindly replayed.** `postJSON` and `putJSON`
-reach `/users/srp/create-session`, `/users/two-factor/verify` — which consumes
-one of a small number of second-factor attempts — and `/files/thumbnail`. They
-are retried only on the three failures that establish no TCP connection to the
-server ever existed, so no request byte can have been transmitted: `ENOTFOUND`
-and `EAI_AGAIN` (name resolution produced no address) and `ECONNREFUSED` (the
-peer refused the connection). A 5xx, a mid-flight reset and a deadline are all
-left to the caller, because each of them can happen after the server has already
-acted. The routing errnos `EHOSTUNREACH`, `ENETUNREACH` and `ENETDOWN` are
-excluded for the same reason, despite looking like connect-time failures: on
-Linux an ICMP unreachable arriving mid-flight, or a local interface going down
-after the request was written, delivers them on an already-established socket.
-They stay retryable for the idempotent calls. `putFile` is exempt: a presigned
-PUT stores one whole object at one key in one request, so replaying it has no
-partial state to damage.
+send every `POST` and `PUT` in the endpoint list above; some of them change
+server state, and `/users/two-factor/verify` consumes one of a small number of
+second-factor attempts. They are retried only when every errno in the error's
+`cause` chain is one of the three that establish no TCP connection to the server
+ever existed, so no request byte can have been transmitted: `ENOTFOUND` and
+`EAI_AGAIN` (name resolution produced no address) and `ECONNREFUSED` (the peer
+refused the connection). A 5xx, a mid-flight reset and a deadline are all left
+to the caller, because each of them can happen after the server has already
+acted. These two do not follow redirects either: a redirect means the server
+already received the request, so it is reported as an error and not retried. The
+routing errnos `EHOSTUNREACH`, `ENETUNREACH` and `ENETDOWN` are excluded for the
+same reason, despite looking like connect-time failures: on Linux an ICMP
+unreachable arriving mid-flight, or a local interface going down after the
+request was written, delivers them on an already-established socket. They stay
+retryable for the idempotent calls. `putFile` is exempt: a presigned PUT stores
+one whole object at one key in one request, so replaying it has no partial state
+to damage.
 
 A download is retried as a whole — request, stream consumption, and decryption —
 because a socket reset after the response headers have arrived surfaces in the
@@ -422,13 +420,28 @@ decides how to persist sessions.
 `client.toJSON()` returns a `ClientSnapshot` (a plain serializable object with
 base64-encoded keys) that the consumer can write to disk, a database, or
 whatever else fits their use case. `Client.fromJSON(snapshot)` restores a
-working client from that snapshot without re-authenticating.
+working client from that snapshot without re-authenticating; it checks every
+field and each key's length first, and throws an error naming the bad field.
+`client.logout()` clears the token and zeroes the key buffers in place; every
+later call on that client throws. It does not contact the server, so the token
+stays valid there and in any saved snapshot; `await client.logoutOnServer()`
+first ends the session on the server (`POST /users/logout`).
 
 The CLI stores the snapshot at the platform-appropriate data directory via
 `env-paths`: `~/Library/Application Support/quak/session.json` on macOS,
 `$XDG_DATA_HOME/quak/session.json` on Linux. The file is written with mode
 `0600`. The key material is stored in cleartext in the JSON; treat this file as
-you would treat the password itself.
+you would treat the password itself. A missing file is reported as "not logged
+in"; a file that exists but is corrupt is reported as such, naming the bad
+field. Both exit with status 1.
+
+`quak logout` ends the session on the server, so the token in `session.json`
+stops working even in a copy of the file, and then deletes the file. If the
+server call fails (or the file is corrupt), the file is still deleted, the
+command says the server session could not be ended, and it exits with status 1.
+It does not delete the cache: it prints the account's cache directory and says
+it still holds decrypted data (file keys in `metadata.json`, cached originals
+and thumbnails), for the user to delete if they want it gone.
 
 ### CLI surface
 
@@ -436,7 +449,7 @@ you would treat the password itself.
 quak [--cache-dir <path>] <command>             global: local metadata/content cache location
 quak login                                      interactive or QUAK_EMAIL/QUAK_PASSWORD
 quak whoami                                     print logged-in account as JSON
-quak logout                                     delete saved session
+quak logout                                     end the session, delete it
 quak collections [--json]                       list all collections
 quak files --collection <id> [--json]           list files in a collection
 quak get <fileID> [--out path] [--collection]   download and decrypt a file
@@ -448,22 +461,40 @@ quak helper fix-missing-thumbnails [--file ids] generate + upload missing thumbn
 ```
 
 Every command runs on the same cache-backed library. The read commands —
-`collections`, `files`, `get`, and `get-thumb` — force a fresh server round-trip
-before they answer, so they report current account state rather than whatever
-the cache last held. `--cache-dir` overrides where the cache lives; without it
-each account gets its own directory under the per-user cache path.
+`collections`, `files`, `get`, `get-thumb`, `backup-metadata`,
+`helper list-missing-thumbnails` and `helper fix-missing-thumbnails` — force a
+fresh server round-trip before they answer, so they report current account state
+rather than whatever the cache last held. If that round-trip fails, the command
+prints the error on one line and exits 1. `--cache-dir` overrides where the
+cache lives; without it each account gets its own directory under the per-user
+cache path.
 
 `get` and `get-thumb` resolve the file by ID directly, so `--collection` is
-accepted for backward compatibility but ignored. `backup-metadata --exif` (alias
-`--all`) additionally downloads each file to extract full EXIF/IPTC/XMP
-metadata. The listing and backup commands support `--json` for machine-readable
-output.
+accepted for backward compatibility but ignored. For a live photo, `get` writes
+its image and its video, each named after the title with its own extension, as
+Ente's clients name them (`IMG_0001.heic` and `IMG_0001.mov`). With
+`--out PATH`, the image is written to `PATH` and the video beside it, with
+`PATH`'s name and the video's extension; a `PATH` with the video's extension is
+refused. `backup-metadata --exif` (alias `--all`) additionally downloads each
+file to extract full EXIF/IPTC/XMP metadata. The listing and backup commands
+support `--json` for machine-readable output.
+
+`backup-metadata` fetches ML data in requests of up to 200 files. When a request
+still fails after its retries, the error is logged, each of its files is written
+with the reason in an `mlDataError` field instead of `mlData`, and the dump goes
+on. The exit code is non-zero if any ML data request failed.
 
 `helper fix-missing-thumbnails` regenerates thumbnails for baseline JPEG images
 only, because the bundled decoder (`jpeg-js`) decodes only JPEG. A non-JPEG
 image (PNG, HEIC) or a video is reported as `skipped` (unsupported format), kept
 distinct from a `failed` repair, and does not affect the exit code; a genuine
-failure still exits non-zero.
+failure still exits non-zero. The server accepts a new thumbnail only from the
+file's owner and only when it is no larger than the thumbnail size it records
+for the file. So a file another account owns, in an album shared with you, is
+skipped by both thumbnail helpers without being fetched, and the fixer skips a
+file whose recorded thumbnail size is 0 or unknown. Otherwise the fixer lowers
+the quality and size of the thumbnail until it fits, and skips the file if even
+the smallest does not.
 
 ### Backup layout
 
@@ -472,18 +503,67 @@ failure still exits non-zero.
 ```
 <dir>/
     originals/
-        <fileID>.<ext>          actual file content (one per unique file)
+        <fileID>.<ext>          actual file content (one per unique file,
+                                two for a live photo: see below)
         <fileID>.json           all decrypted metadata for that file
+        <fileID>.livephoto.json which of a live photo's two files is which
     collections/
         <name>/
             <title> -> ../../originals/<fileID>.<ext>   (symlink)
         <name>.json             collection metadata + file list
+    failures.json               files that failed and have not yet succeeded
 ```
 
+`failures.json` records each failed file with the kind of failure, how many
+times it has been tried and when it was last tried. A file leaves it once it
+succeeds, or once it is no longer in the library or in the backup's scope. The
+library's `lib.backup({ includeThumbnails: true })` also writes
+`thumbnails/<fileID>.jpg` beside `originals/`; `quak backup` does not.
+
+A collection's directory and JSON are named after the collection, and a symlink
+after the file's title, both with unsafe characters replaced. When two
+collections would get the same name, or two symlinks in one collection the same
+name (ignoring case in both), each of them gets its ID added: two albums named
+`Trip` become `Trip (10)/` and `Trip (11)/`, and two files titled `IMG_0001.JPG`
+become `IMG_0001 (12345).JPG` and `IMG_0001 (12346).JPG`. IDs never change, so a
+name stays the same from run to run until such a clash appears or goes away.
+
+A live photo, which Ente stores as one ZIP of its image and its video, is stored
+as those two files, which a photo viewer can open: each is
+`originals/<fileID>.<ext>` with the extension it has inside the ZIP (for example
+`12345.heic` and `12345.mov`), and `<fileID>.livephoto.json` names the two. The
+live photo counts as stored only when both files are present and not empty. Its
+album folder links both, each named after the title with that file's extension
+(`IMG_0001.heic` and `IMG_0001.mov`). A live photo that an earlier version of
+quak stored as the ZIP, under the image's name, is replaced by its two files on
+the next run, and the ZIP and its link are removed.
+
+Each run removes the symlinks into `originals/` that no longer belong in their
+collection's directory, and the directories (and JSON) of collections that were
+deleted or renamed. Nothing else in `collections/` is touched: a file or a
+symlink you put there stays, and a directory that still holds one after its
+symlinks are removed stays too, with its JSON.
+
 Each file is downloaded exactly once regardless of how many collections it
-appears in. On subsequent runs, existing originals are skipped. If a download
-fails, the error is logged and the backup continues with the next file. The exit
-code is non-zero if any files failed.
+appears in, and written once: straight into `originals/`, with no copy left in
+the cache. An original the cache already held is copied from there instead. On
+subsequent runs, existing originals are skipped. If a download fails, the error
+is logged and the backup continues with the next file. The exit code is non-zero
+if any files failed. `quak backup` opens its library with the thumbnail and
+originals precache off, so it fetches only what the backup stores.
+
+Each original is written to a temporary file in the same directory, synced to
+disk, and renamed into place, so an original is either complete or absent, even
+after a power cut. A downloaded original's temporary file is named
+`.quak-<pid>-<random>.tmp`, one copied from the cache
+`.quak-backup-<fileID>.<ext>-<pid>-<random>.tmp`. A run that is killed can leave
+one of these temporary files behind; the next backup deletes those whose process
+is no longer running. The content cache uses the same scheme, and opening a
+library deletes the temporary files in the cache whose process is no longer
+running, so a download another process has in progress in the same cache is left
+alone. The rename replaces whatever was at the destination rather than writing
+through it: a symlink there is replaced, not followed, and the new file has the
+temporary file's permissions, not those of the file it replaced.
 
 ## TODO
 
@@ -491,7 +571,12 @@ code is non-zero if any files failed.
       errors
 - [x] Update the API reference section below to match the current implementation
 - [x] `make docker` green
-- [ ] Tag `v1.0.0`
+- [x] Store live photos in a form a photo viewer can open
+      (https://git.eeqj.de/sneak/quak/issues/107): unpacked into the image and
+      the video
+
+Tagging and releases are decided by sneak alone, and happen only when he
+declares one.
 
 Future (desktop client, separate repo):
 
@@ -511,10 +596,11 @@ test suite is the canonical, executable documentation — `test/library/` and
 ### Opening a library
 
 `Library.open(options)` loads the on-disk cache, starts the background refresh
-loop, and resolves to a `Library`. On an empty cache it awaits the first refresh
-so it never opens onto empty data; on an existing cache it returns immediately
-and refreshes in the background, so an unreachable server does not block
-opening.
+loop, and resolves to a `Library`. On an empty cache it awaits the first
+refresh, so it opens onto the account's data whenever the server is reachable;
+if that refresh fails, it opens with no data and records the error in
+`lib.status()`. On an existing cache it returns immediately and refreshes in the
+background, so an unreachable server does not block opening.
 
 `LibraryOptions`:
 
@@ -541,7 +627,10 @@ and pass it. The three pools default to 10 / 5 / 25 (see Request pools below).
 `lib.status()` returns a `LibraryStatus` (collection/file counts, last
 refresh/ML times and errors, originals usage and effective limit, precache
 progress, and `closed`). `lib.close()` stops the background timer; it is
-idempotent, and an in-flight refresh is left to finish.
+idempotent, and an in-flight refresh is left to finish. The promise it returns
+resolves once that refresh (including its cache write), the ML data fetch and
+the precache fetches already running have all finished, so the cache directory
+can then be removed.
 
 ### Default reads vs. fresh reads
 
@@ -576,7 +665,9 @@ An `Album` exposes its record fields and `album.photos.list()` → `Photo[]`
 (newest first). A `Photo` exposes its record fields, `photo.record()` →
 `PhotoRecord`, and two content methods:
 
-- `await photo.original(opts?)` → `{ path, bytes }` — the full-resolution file.
+- `await photo.original(opts?)` → `{ path, bytes, videoPath? }` — the
+  full-resolution file. For a live photo, `path` and `bytes` are its image's and
+  `videoPath` is its video.
 - `await photo.thumbnail(opts?)` → `{ path, bytes }`.
 
 Both serve from the on-disk content cache when the bytes are present and
@@ -596,7 +687,7 @@ The GUI-facing records hold no key material and no binary, so they survive
 - `PhotoRecord`: `fileID`, `albumIDs`, `title`, `takenAt` (milliseconds),
   `fileType`, optional `caption` / `width` / `height` / `latitude` /
   `longitude`, `isArchived`, `isHidden`, and `thumbnailPath` / `originalPath`
-  once the bytes are cached.
+  once the bytes are cached (for a live photo, `originalPath` is its image).
 - `AlbumRecord`: `collectionID`, `name`, `type`, `isShared`, `updationTime`, and
   `fileIDs` (newest first).
 - `LibrarySnapshot`: `{ albums, photos, takenAt }`.
@@ -622,12 +713,15 @@ photos newest first). `lib.subscribe({ onChange })` delivers a `LibraryChange`
   default limit 20). quak bundles no text encoder, so `searchByEmbedding` takes
   a query vector the caller produced elsewhere.
 - `await lib.backup(opts?)` → `BackupResult`. It refreshes, fetches every
-  in-scope original (and, with `includeThumbnails`, thumbnails) through the
-  content cache, and rebuilds the on-disk backup tree with a durable failure
-  ledger. `BackupOptions`: `downloadDirectory` (falls back to the one `open()`
-  was given), `includeOriginals` (default `true`), `includeThumbnails` (default
-  `false`), `onlyAlbumNames`, and `onProgress`. See Backup layout above for the
-  tree it writes.
+  in-scope original not already in the backup (and, with `includeThumbnails`,
+  thumbnails) through the content cache, and rebuilds the on-disk backup tree
+  with a durable failure ledger. A fetched original is written straight into the
+  backup's `originals/` and not into the cache, which then counts it as present;
+  one the cache already held is copied from there. `BackupOptions`:
+  `downloadDirectory` (falls back to the one `open()` was given),
+  `includeOriginals` (default `true`), `includeThumbnails` (default `false`),
+  `onlyAlbumNames`, and `onProgress`. See Backup layout above for the tree it
+  writes.
 
 ### Request pools
 
@@ -644,6 +738,8 @@ Under `cacheDirectory`:
 <cacheDirectory>/
     metadata.json                 decrypted account state + refresh cursor
     originals/<fileID>.<ext>      cached full-resolution files
+    originals/<fileID>.livephoto.json
+                                  which of a live photo's two files is which
     thumbnails/<fileID>.jpg       cached thumbnails
     mldata/
         <fileID>.json             one decrypted ML payload per file
@@ -651,11 +747,26 @@ Under `cacheDirectory`:
         fetched.json              per-file fetch bookkeeping
 ```
 
+When `metadata.json` belongs to a different account than the client's,
+`Library.open` deletes it and `mldata/` and starts from an empty cache. Cached
+originals and thumbnails are kept; they are reached only through the files the
+current account's records name.
+
+A live photo's original is cached as in the backup: its image and its video,
+each `originals/<fileID>.<ext>` with its own extension, and
+`originals/<fileID>.livephoto.json` naming them; the two are evicted together. A
+live photo that an earlier version cached as its ZIP is not served, and is
+replaced by its two files the next time it is read.
+
 A stored file appears only via an atomic temp-then-rename, so its presence means
-it is complete. The design also calls for a content-hash comparison against
-`FileMetadata.hash` on each fetched original; that check is deferred (issue
-https://git.eeqj.de/sneak/quak/issues/68) because the exact hash construction
-cannot yet be confirmed against the repo's fixtures.
+it is complete. Every downloaded original (by `quak get`, the cache, or
+`backup`) whose metadata records a content hash (`FileMetadata.hash`) is hashed
+as it is written: unkeyed BLAKE2b with a 64-byte output, standard base64. A live
+photo arrives as a ZIP and is unpacked as it is written; its image and its video
+are hashed separately and joined as `<imageHash>:<videoHash>`, and neither is
+stored unless both are complete and match. A mismatch stores nothing and fails
+the download with an error naming the file ID. An original with no recorded
+hash, from a very old client, is stored unchecked.
 
 ### Key types by source file
 
@@ -704,20 +815,22 @@ documents:
   commented thoroughly. `main` is always green.
 
 - **Required checks before every commit:** `make lint` must pass — that is
-  eslint plus the prettier check, and it builds `Dockerfile.lint`, so it needs
-  docker. The pre-commit hook enforces exactly that. `make check` (which also
-  runs the tests) must pass before merging to `main`. `make fmt-check` is
-  available for a host-side formatting check on its own, but it is not a
-  separate requirement: `make lint` already covers it, and running both would
-  check formatting twice. Never invoke eslint or prettier directly; linting runs
-  in the container only.
+  eslint plus the prettier check, and it builds the `lint` phase of the
+  `Dockerfile`, so it needs docker. The pre-commit hook enforces exactly that.
+  `make check` (which also runs the tests) must pass before merging to `main`.
+  `make fmt-check` is available for a host-side formatting check on its own, but
+  it is not a separate requirement: `make lint` already covers it, and running
+  both would check formatting twice. Never invoke eslint or prettier directly;
+  linting runs in the container only.
 
 - **Formatting:** prettier with 4-space indents and `proseWrap: always` for
   markdown. Use `make fmt` to format. Use `yarn` not `npm`.
 
 - **Testing:** vitest. Tests go in `test/` mirroring the `src/` structure.
-  `make test` must complete in under 20 seconds. Use `mkdtempSync` for temporary
-  directories, never manual timestamp paths.
+  `make test` must finish in under 60 seconds (the hard cap) and should finish
+  in under 20. The 90-second `timeout` in the `test` phase of the `Dockerfile`
+  is a backstop that catches a hung test, not the time limit. Use `mkdtempSync`
+  for temporary directories, never manual timestamp paths.
 
 - **Code style:** `const` for everything, `let` if reassignment is needed, never
   `var`. Avoid unnecessary comments. No hand-rolled crypto. The

REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-07-06
+last_modified: 2026-09-08
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -60,17 +60,28 @@ style conventions are in separate documents:
   prerequisite since nvm requires bash. yarn is then pinned via
   `corepack prepare yarn@<version> --activate`. Never install "latest" or "lts";
   always exact versions. `script/cibuild` runs the CI build: it changes to the
-  repo root and runs `docker build .`; the Gitea workflow calls it. Four further
-  scripts are our own extensions to the standard: `script/check` runs
-  `script/test`, `script/lint`, and `script/fmt-check`; `script/precommit` is
-  what the git pre-commit hook runs, and it calls `script/check`;
-  `script/install-precommit` installs the git pre-commit hook (the `make hooks`
-  target shims to it); and `script/projectname` (literally that filename) simply
-  outputs the project's name. Scripts that need the name call
-  `script/projectname` — e.g. `script/docker` assembles its image tag from it —
-  so those scripts stay byte-identical across all repos. Repo-type-specific
-  pre-commit extras (e.g. `go mod tidy` verification in Go repos) belong in
-  `script/precommit`, not in the hook itself. Model scripts are at
+  repo root, runs `script/bootstrap`, runs `script/check`, and builds the image
+  with the version; the Gitea workflow calls it. **`script/cibuild` runs
+  `script/bootstrap` first**, because the workflow checks out the repo and runs
+  nothing else, while `script/fmt-check` runs the formatter on the host: on a
+  pristine checkout with nothing installed the run dies there, after the
+  containerised gates have passed. **The bootstrap alone is not enough**:
+  `script/bootstrap` installs node and yarn under nvm and leaves neither on the
+  `PATH` of the shell that called it, so a bare `yarn` still exits 127. The host
+  entrypoints that need yarn — `script/fmt` and `script/fmt-check` — therefore
+  source nvm for the pinned node version before invoking it, exactly as
+  `script/bootstrap`'s own install step does. A runner carrying nothing but
+  docker and git then gets through `script/check`. Four further scripts are our
+  own extensions to the standard: `script/check` runs `script/test`,
+  `script/lint` and `script/fmt-check`; `script/precommit` is what the git
+  pre-commit hook runs, and it calls `script/check`; `script/install-precommit`
+  installs the git pre-commit hook (the `make hooks` target shims to it); and
+  `script/projectname` (literally that filename) simply outputs the project's
+  name. Scripts that need the name call `script/projectname` — e.g.
+  `script/docker` assembles its image tag from it — so those scripts stay
+  byte-identical across all repos. Repo-type-specific pre-commit extras (e.g.
+  `go mod tidy` verification in Go repos) belong in `script/precommit`, not in
+  the hook itself. Model scripts are at
   `https://git.eeqj.de/sneak/prompts/raw/branch/main/script/<name>`. The README
   must document the provided scripts in an **Entrypoints** section (see the
   README requirements below).
@@ -89,87 +100,140 @@ style conventions are in separate documents:
   contributor should be able to understand the entire development workflow by
   reading the Makefile.
 
-- Every repo should have a `Dockerfile`. All Dockerfiles must run `make check`
-  as a build step so the build fails if the branch is not green. For non-server
-  repos, the Dockerfile should bring up a development environment and run
-  `make check`. For server repos, `make check` should run as an early build
-  stage before the final image is assembled. Dockerfiles install development
-  prerequisites by running `script/bootstrap` rather than duplicating installs
-  inline; COPY `script/` and the dependency manifests (`package.json` +
-  `yarn.lock`, `go.mod` + `go.sum`, etc.) before running it so the bootstrap
-  layer stays cached until dependencies change.
+- Every repo should have a `Dockerfile`, and it carries the repo's gates: a
+  `lint` phase and a `test` phase, with the final stage depending on both so the
+  image cannot be built unless they pass. For non-server repos the final stage
+  brings up a development environment; for server repos it is the runtime image.
+  Dockerfiles install development prerequisites by running `script/bootstrap`
+  rather than duplicating installs inline; COPY `script/` and the dependency
+  manifests (`package.json` + `yarn.lock`, `go.mod` + `go.sum`, etc.) before
+  running it.
 
-- **Dockerfiles must use a separate lint stage for fail-fast feedback.** Go
-  repos use a multistage build where linting runs in an independent stage based
-  on the `golangci/golangci-lint` image (pinned by hash). This stage runs
-  `make fmt-check` and `make lint` before the full build begins. The build stage
-  then declares an explicit dependency on the lint stage via
-  `COPY --from=lint /src/go.sum /dev/null`, which forces BuildKit to complete
-  linting before proceeding to compilation and tests. This ensures lint failures
-  surface in seconds rather than minutes, without blocking on dependency
-  download or compilation in the build stage.
+- **Linting and testing run in Docker, as phases of the `Dockerfile`.** There is
+  no separate lint file. `script/lint` and `script/test` each build one phase
+  and nothing else:
 
-    The standard pattern for a Go repo Dockerfile is:
+    ```sh
+    docker build --no-cache --target lint -t "$(script/projectname)-lint" .
+    docker build --no-cache --target test -t "$(script/projectname)-test" .
+    ```
+
+    **A stage that is not the last one in the file is built only when the final
+    stage's chain depends on it, or when `--target` names it.** That is why the
+    two gates are always invoked by name here, and why the final stage carries a
+    `COPY --from=` of a harmless file from each of them: without that edge a
+    plain `docker build .` builds the last stage alone and exits 0 having linted
+    and tested nothing.
+
+    **Every `docker build` in `script/` is tagged**, here and in
+    `script/cibuild` and `script/docker`. An untagged build leaves a dangling
+    image behind on every invocation, on every developer host and every CI
+    runner; a tagged one replaces the previous image.
+
+    Inside a phase the tool is invoked directly — `golangci-lint`, `go test`,
+    `eslint`, `prettier` — never through `make lint` or `script/test`, which are
+    themselves a `docker build` and would recurse into a daemon that does not
+    exist in a build step. Formatting is the exception and stays on the host:
+    `script/fmt` writes the working tree, and `script/fmt-check` is its
+    read-only twin.
+
+    **No lint verdict may come from a host invocation of the linter.** On a
+    shared host golangci-lint reads a result cache keyed on file content rather
+    than location, so a second checkout of the same content is served the first
+    one's findings, and a host-global lock in `$TMPDIR` makes concurrent runs
+    exit non-zero with `parallel golangci-lint is running` — a status a caller
+    cannot tell from real findings. Both have produced wrong verdicts in this
+    org, in both directions. A container has its own cache, its own `TMPDIR` and
+    a digest-pinned binary, so neither is reachable.
+
+- **Any build that runs checks is built with `--no-cache`.** Docker invalidates
+  a `COPY` layer only when the copied content changes, so on an unchanged tree
+  the check `RUN` is served from cache, nothing executes, and the build still
+  exits 0. Every `docker build` in `script/` therefore passes `--no-cache`:
+  `script/lint`, `script/test`, `script/cibuild` and `script/docker` are the
+  four, and there is no fifth — `script/check` runs the two gate phases and
+  `script/fmt-check`, and builds no image of its own. A bare `docker build .` is
+  not evidence that anything ran: a sub-second build reporting success is a
+  cache hit, not a result. Never invalidate by pruning — `docker builder prune`
+  and friends destroy a build cache shared with every other build on the host.
+
+- **The gate phases are separate stages, and the build stage depends on both.**
+  The lint phase is based on the `golangci/golangci-lint` image (pinned by
+  hash), so lint failures surface in seconds rather than after a full compile,
+  and the test phase is based on the Go image. The canonical Go repo
+  `Dockerfile`:
 
     ```dockerfile
-    # Lint stage — fast feedback on formatting and lint issues
+    # Lint phase
     # golangci/golangci-lint:v2.x.x, YYYY-MM-DD
     FROM golangci/golangci-lint@sha256:... AS lint
     WORKDIR /src
     COPY go.mod go.sum ./
     RUN go mod download
     COPY . .
-    RUN make fmt-check
-    RUN make lint
+    RUN golangci-lint run --config .golangci.yml ./...
 
-    # Build stage
+    # Test phase
     # golang:1.x-alpine, YYYY-MM-DD
+    FROM golang@sha256:... AS test
+    WORKDIR /src
+    COPY go.mod go.sum ./
+    RUN go mod download
+    COPY . .
+    RUN go test -timeout 90s -race -cover ./... || \
+        { echo "--- Rerunning with -v for details ---"; \
+          go test -timeout 90s -race -v ./...; exit 1; }
+
+    # Build stage. Nothing is wanted from either phase above; the copies
+    # are what make BuildKit build them first, so this stage cannot run
+    # unless lint and test passed.
+    # golang:1.x-alpine, YYYY-MM-DD
     FROM golang@sha256:... AS builder
+    COPY --from=lint /src/go.sum /dev/null
+    COPY --from=test /src/go.sum /dev/null
     WORKDIR /src
-
-    # Force BuildKit to run the lint stage before proceeding
-    COPY --from=lint /src/go.sum /dev/null
-
     COPY go.mod go.sum ./
     RUN go mod download
     COPY . .
-    RUN make test
 
     ARG VERSION=dev
     RUN CGO_ENABLED=0 go build -trimpath \
         -ldflags="-s -w -X main.Version=${VERSION}" \
         -o /app ./cmd/app/
 
-    # Runtime stage
+    # Runtime stage, and the last one
     FROM alpine@sha256:...
     COPY --from=builder /app /usr/local/bin/app
     ENTRYPOINT ["app"]
     ```
 
     Key points:
-    - The lint stage uses the `golangci/golangci-lint` image directly (it
-      includes both Go and the linter), so there is no need to install the
-      linter separately.
-    - `COPY --from=lint /src/go.sum /dev/null` is a no-op file copy that creates
-      a stage dependency. BuildKit runs stages in parallel by default; without
-      this line, the build stage would not wait for lint to finish and a lint
-      failure might not fail the overall build.
+    - The lint phase uses the `golangci/golangci-lint` image directly (it has
+      both Go and the linter), so nothing needs installing.
+    - `COPY --from=<phase> /src/go.sum /dev/null` is a no-op copy whose only
+      purpose is the ordering edge. BuildKit runs stages in parallel by default,
+      and a stage nothing depends on is not built at all, so without these two
+      lines a red gate would not fail the build.
+    - Keep the runtime stage last, and if you add a stage after it, give it the
+      same two copies. A plain `docker build .` builds the last stage's chain
+      and nothing else.
     - If the project uses `//go:embed` directives that reference build artifacts
-      (e.g. a web frontend compiled in a separate stage), the lint stage must
+      (e.g. a web frontend compiled in a separate stage), the lint phase must
       create placeholder files so the embed directives resolve. Example:
       `RUN mkdir -p web/dist && touch web/dist/index.html web/dist/style.css`.
-      The lint stage should not depend on the actual build output — it exists to
-      fail fast.
     - If the project requires CGO or system libraries for linting (e.g.
-      `vips-dev`), install them in the lint stage with `apk add`.
-    - The build stage runs `make test` after compilation setup. Tests run in the
-      build stage, not the lint stage, because they may require compiled
-      artifacts or heavier dependencies.
+      `vips-dev`), install them in the lint phase with `apk add`.
+    - `ARG VERSION=dev` is declared in the stage that compiles and supplied by
+      `script/docker` and `script/cibuild`; no stage may call `git describe`.
 
 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
-  runs `script/cibuild` (which runs `docker build .`) on push. Since the
-  Dockerfile already runs `make check`, a successful build implies all checks
-  pass.
+  runs `script/cibuild` on push, and checks out the repo as its only other step.
+  That script bootstraps, runs the gate phases, and then builds the image, so a
+  successful run means every check passed; a bare `docker build .` does not
+  carry the same guarantee, because its gate phases may come from the cache. The
+  image build is uncached and so runs the gate phases a second time. That is the
+  price of the rule above, and it is worth paying: the image that ships is built
+  from a run of its own gates rather than from a cache entry.
 
 - Use platform-standard formatters: `black` for Python, `prettier` for
   JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
@@ -189,14 +253,21 @@ style conventions are in separate documents:
   module under test to verify it compiles/parses. There is no excuse for
   `make test` to be a no-op.
 
-- `make test` must complete in under 20 seconds. Add a 30-second timeout in the
-  Makefile.
+- `make test` must complete in under 60 seconds. That is the hard cap, and a
+  suite that exceeds it fails. Under 20 seconds is the target. A suite between
+  20 and 60 seconds is still green, but the overage must be filed as an
+  improvement bug against that repo. Add a 90-second timeout to the test
+  invocation (`go test -timeout 90s`). The backstop deliberately sits above the
+  hard cap so that it catches a genuinely hung test rather than a merely slow
+  one.
 
-- **`make test` should use the conditional verbose rerun pattern.** Run tests
-  without `-v` (verbose) first. If tests fail, automatically rerun with `-v` to
-  show full output. This keeps CI logs and `docker build` output clean on
-  success (just package/suite summaries) while providing full diagnostic detail
-  on failure (every test case, every assertion). The general shell pattern:
+- **The test command should use the conditional verbose rerun pattern.** Run
+  tests without `-v` (verbose) first. If tests fail, automatically rerun with
+  `-v` to show full output. This keeps CI logs and `docker build` output clean
+  on success (just package/suite summaries) while providing full diagnostic
+  detail on failure (every test case, every assertion). The command lives in the
+  `test` phase of the `Dockerfile`, since `script/test` builds that phase; the
+  Makefile form below is the same pattern for any repo-local invocation:
 
     ```makefile
     test:
@@ -209,11 +280,24 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@go test -timeout 30s -race -cover ./... || \
+    	@go test -count=1 -timeout 90s -race -cover ./... || \
     		{ echo "--- Rerunning with -v for details ---"; \
-    		  go test -timeout 30s -race -v ./...; exit 1; }
+    		  go test -count=1 -timeout 90s -race -v ./...; exit 1; }
     ```
 
+    `-count=1` is required on both invocations: it defeats Go's test _result_
+    cache, so the target cannot report a pass it did not earn, and the rerun
+    reproduces a failure instead of replaying it. It leaves the build cache
+    alone, so it costs the runtime of the suite and no recompilation.
+
+    Note that this is a second, independent cache, stacked below the Docker
+    layer cache that [issue #26](https://git.eeqj.de/sneak/prompts/issues/26)
+    addresses. `CHECK_EPOCH` guarantees the `RUN make test` _step_ re-executes;
+    it does not guarantee `go test` inside that step does any work, because the
+    `GOCACHE` baked into earlier image layers survives into the re-executed
+    step. They are two separate defects requiring two separate fixes, and a fix
+    for one must not be recorded as covering the other.
+
     Python example:
 
     ```makefile
@@ -239,10 +323,83 @@ style conventions are in separate documents:
   must be in `.gitignore`. No exceptions.
 
 - `.gitignore` should be comprehensive from the start: OS files (`.DS_Store`),
-  editor files (`.swp`, `*~`), language build artifacts, and `node_modules/`.
-  Fetch the standard `.gitignore` from
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when setting up
-  a new repo.
+  editor files (`.swp`, `*~`), in-repo agent scratch directories (`.claude/`),
+  language build artifacts, and `node_modules/`. Fetch the standard `.gitignore`
+  from `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when
+  setting up a new repo. These patterns are written to `.gitignore`'s own
+  semantics, in which an unanchored pattern already matches at every depth; they
+  are not a `.dockerignore` and must not be transplanted into one unmodified.
+
+- **`.dockerignore` does not use `.gitignore` semantics, and copying patterns
+  across unmodified leaves secrets in the build context.** Docker matches with
+  `moby/patternmatcher`: `filepath.Match` semantics plus a `**` extension, so
+  `*` does not cross `/` and a pattern without a leading `**/` is anchored at
+  the build-context root. A `.dockerignore` listing `.env`, `*.pem` and `*.key`
+  therefore excludes only the copies at the repository root, while `config/.env`
+  and `certs/server.key` still reach the context and can land in an image layer
+  — which is more dangerous than a short file with no secret patterns at all,
+  because it reads as solved and stops anyone looking. Give every
+  depth-independent pattern the `**/` prefix and leave only genuinely
+  root-anchored entries unprefixed: `.git`, and the repo's own host-built
+  binary, written `/myapp` and never `**/myapp`, which would also match
+  `cmd/myapp/` and delete the package directory from the context. Matching is
+  case-sensitive, and an ALL-CAPS twin per pattern still misses `Server.Key`, so
+  secret names use character ranges — `**/*.[kK][eE][yY]`, `**/*.[pP][eE][mM]`,
+  and likewise for `.envrc` and the extensionless SSH keys. Where such a pattern
+  also catches something the build needs, re-include it with a negation
+  (`!docs/example.env`); deleting the pattern reopens the exposure for every
+  other file it covers. Fetch the standard `.dockerignore` from
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.dockerignore` and extend
+  it with the repo's own artifacts.
+
+- **In-repo agent scratch belongs in both files, written to each file's own
+  semantics.** `.claude/` holds one worktree per in-flight agent — an entire
+  additional checkout of the repo — so under `COPY . .` the build context
+  inflates by a multiple of the repo and another session's unreviewed work can
+  be copied into an image layer. In `.gitignore` the entry is `.claude/`,
+  unanchored. In `.dockerignore` it is `.claude`, anchored and with **no** `**/`
+  prefix, because the prefixed form would also delete any nested directory of
+  that name from the build. Anchoring carries a known gap that the canonical
+  `.dockerignore` states in its own comment, since consuming repos receive the
+  file and not the tracker: the directory is created in the agent's working
+  directory, so a repo running agents in subdirectories still ships
+  `services/api/.claude/` and must add its own anchored entry there.
+
+- **Excluding `.git` means `git describe` cannot run inside any build stage, and
+  it fails quietly there.** In a build stage there is no repository, so
+  `git describe` writes nothing to stdout, `-X main.Version=` comes out empty,
+  the binary reports no version at all, and the build still exits 0. Compute the
+  version on the host and thread it in as a build arg. `script/docker` and
+  `script/cibuild` do this, byte-identically across repos:
+
+    ```sh
+    # Own line: a failing command substitution inside an argument does not
+    # trip `set -e`, so the inline form degrades to an empty constant.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$(script/projectname)" .
+    ```
+
+    `--always` makes an untagged repo yield an abbreviated commit hash rather
+    than failing, and the `[ -n "$version" ]` line is the single place the
+    fallback is applied — a live check that fires on a build from an export with
+    no `.git` and on a repository with no commits yet. Do not fold it into the
+    substitution as `|| echo unknown`, which makes the guard unreachable. The
+    Dockerfile's side is `ARG VERSION=dev` in the stage that compiles, declared
+    there because `ARG` is stage-scoped; passing `VERSION` to a repo whose
+    Dockerfile declares no such `ARG` is ignored and costs nothing, which is why
+    the scripts stay byte-identical. One consequence for CI: the standard
+    checkout action clones shallow and fetches no tags, so a repo that embeds a
+    tag-derived version must set `fetch-depth: 0` on its checkout step.
+
+- **Verify `.dockerignore` by enumerating the image, not by reading the
+  patterns.** Plant files at the root _and_ at least two directories deep, build
+  a probe image that does `COPY . .`, and list what actually landed
+  (`docker run --rm --entrypoint find IMAGE /app`). The `transferring context`
+  size is not a substitute: a nested secret is a few bytes, and BuildKit
+  transfers only the delta from the previous build.
 
 - **No build artifacts in version control.** Code-derived data (compiled
   bundles, minified output, generated assets) must never be committed to the
@@ -258,9 +415,45 @@ style conventions are in separate documents:
 - Make all changes on a feature branch. You can do whatever you want on a
   feature branch.
 
-- `.golangci.yml` is standardized and must _NEVER_ be modified by an agent, only
-  manually by the user. Fetch from
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml`.
+- `.golangci.yml` is standardized. The vendored copy in a consuming repo must
+  _NEVER_ be modified by an agent: fetch it from
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml` and keep it
+  byte-identical, so that no repo can quietly loosen its own linting. Linter
+  configuration changes are made to the canonical copy in the `prompts` repo and
+  reach consuming repos by re-vendoring; an agent may open a PR against
+  canonical, which only the user merges. One list is exempt from byte-identity,
+  because it cannot be written once for every repo: the `deny` list of the
+  `test-support` depguard rule, where a repo names its own test-support packages
+  by full import path. A repo adds entries there and changes nothing else, and a
+  re-vendor carries its entries forward. The canonical golangci-lint version is
+  v2.12.2 (released 2026-05-06), pinned as the digest of the lint phase's base
+  image
+  (`golangci/golangci-lint@sha256:5cceeef04e53efe1470638d4b4b4f5ceefd574955ab3941b2d9a68a8c9ad5240`,
+  which reports `2.12.2 built with go1.26.2 from c0d3ddc9`). That digest is the
+  only pin, since no repo installs golangci-lint on the host: bumping the
+  version means changing it and nothing else.
+
+- **`script/bootstrap` installs a pinned tool by comparing versions, never by
+  testing presence.** An `if ! command -v <tool>; then install; fi` guard tests
+  `PATH` only, so on an already-provisioned machine the pin is inert and a
+  version bump is a silent no-op — while the Dockerfile, installing into a clean
+  image, gets the pinned version, so a local `make check` and `make docker` can
+  disagree about what the tool even is. The canonical form:
+    - compares the installed version against the pin over the **whole** version
+      token; a parser that stops at the first `-` reports `2.12.2` for a host
+      running `2.12.2-rc1` and skips the install;
+    - treats absent, non-zero, empty or unrecognised `--version` output as a
+      mismatch, so the failure direction is a redundant install and never a
+      skipped one;
+    - after installing, re-resolves the binary the way callers do — `hash -r`,
+      then through `PATH`, not through the directory the installer wrote to —
+      and fails naming the resolved path, since an install that a shadowing
+      binary hides succeeds while changing nothing any caller sees;
+    - is actually called, and prints the version on both success paths: a
+      function defined and never invoked has the same exit status and the same
+      empty output as one that worked.
+
+    Keep it POSIX sh: no arrays, no `[[`, no `grep -P`.
 
 - When pinning images or packages by hash, add a comment above the reference
   with the version and date (YYYY-MM-DD).
@@ -379,7 +572,9 @@ style conventions are in separate documents:
   language-specific config). Everything else goes in a subdirectory. Canonical
   subdirectory names:
     - `bin/` — executable scripts and tools
-    - `cmd/` — Go command entrypoints
+    - `cmd/` — Go command entrypoints; thin only: one `main.go` per binary whose
+      body is a single call into `internal/` or `pkg/`, no project logic in
+      `cmd/`
     - `configs/` — configuration templates and examples
     - `deploy/` — deployment manifests (k8s, compose, terraform)
     - `docs/` — documentation and markdown (README.md stays in root)

TODO.md

@@ -14,10 +14,216 @@ pre-1.0
 
 # Next Step
 
-Tag v1.0.0.
+None: every issue still open is done on `next` or `next2` and waits for it to
+reach `main`.
+
+Tagging and releases are decided by sneak alone, and happen only when he
+declares one.
 
 # Completed Steps
 
+- 2026-09-23: Live photos are stored as their image and their video (issue 107).
+  A live photo, which Ente stores as one ZIP, is unpacked as it downloads into
+  `<fileID>.<ext>` for the image and for the video, each with its extension from
+  the ZIP, beside `<fileID>.livephoto.json`, which names the two. Both are
+  checked against the recorded hash and renamed into place only when both are
+  complete. The backup and the content cache count the live photo as stored only
+  with both files, the album folder links both, `quak get` writes both, and the
+  content result gives the video as `videoPath`. A ZIP an earlier version stored
+  is replaced on the next backup run, and in the cache when the photo is next
+  read.
+
+- 2026-09-23: Settled the package metadata (issue 6). quak is not published, so
+  `package.json` is marked `"private": true` and the `files` field is gone.
+  `engines.node` is `>=22`, the major version `script/bootstrap` and the
+  `Dockerfile` use. An `exports` map makes `.` and `./package.json` the only
+  importable paths; `runMetadataBackup`, the thumbnail helpers and their types
+  stay internal to the CLI.
+
+- 2026-09-23: Brought the README and this file in line with the tree (issue
+  111). The layout lists `src/library/` and the other source files, the backup
+  layout names `failures.json` and the optional `thumbnails/`, "Opening a
+  library" says what happens when the first refresh fails, the Testing section
+  gives the 60-second hard cap and 20-second target for `make test` and names
+  the 90-second `timeout` in the `Dockerfile` as the backstop for a hung test,
+  and "Tag v1.0.0" is no longer listed as the next step.
+
+- 2026-09-23: Tested `quak login` and `backup-metadata --exif` (issue 110).
+  `loginCommand` takes its login function and its prompts from `CliContext`, and
+  `bin/quak.ts` passes `Client.login` and the terminal prompts. Tests cover a
+  login from `QUAK_EMAIL` and `QUAK_PASSWORD` with no prompt, the TOTP prompt, a
+  failed login, and the saved session's modes, and show that `--exif` and
+  `--all` each turn on EXIF extraction and that it is off without them.
+
+- 2026-09-23: `quak backup` writes each original once and no longer fills the
+  cache (issue 106). An original fetched for a backup is written by the download
+  writer straight into the backup's `originals/`, and the content cache records
+  it there instead of keeping its own copy; one the cache already held is still
+  copied. `quak backup` opens its library with the thumbnail and originals
+  precache off.
+
+- 2026-09-23: `backup-metadata`, `helper list-missing-thumbnails` and
+  `helper fix-missing-thumbnails` refresh before they answer (issue 100). Each
+  awaits `lib.fresh()` before reading, so a file added since the cache was
+  written is included, and a failed refresh prints one line and exits 1 instead
+  of answering from a stale or empty cache. The README lists them among the
+  commands that refresh first.
+
+- 2026-09-23: `quak backup` waits for the server refresh and fails when it fails
+  (issue 99). `lib.backup()` joins a refresh already running or starts one, as
+  `fresh()` does, and rejects before touching any file when it fails, leaving
+  `failures.json` as it was, so `quak backup` prints the error as one line and
+  exits 1 instead of backing up the previous run's file list, or nothing, and
+  exiting 0.
+
+- 2026-09-23: CLI errors print a message instead of a stack trace (issue 102).
+  An error a command throws is printed as one `quak: MESSAGE` line on stderr and
+  the CLI exits 1 once output has drained. The wrapper that does this moved from
+  `bin/quak.ts` to `src/cli-run.ts`, and `bin/quak.ts` now awaits
+  `program.parseAsync()`.
+
+- 2026-09-23: Opening a library no longer deletes another process's download in
+  progress (issue 105). The download writer's temp files are named
+  `.quak-<pid>-<random>.tmp`, and `removeLeftoverTempFiles`, moved from the
+  backup into the download module, deletes a `.quak-*.tmp` file only when the
+  process ID in its name is no longer running. The content cache calls it at
+  `open()` for `originals/` and `thumbnails/`, the backup as before.
+
+- 2026-09-23: Re-vendored the lint and test setup from the template (issue 96).
+  Linting and testing are the `lint` and `test` phases of the `Dockerfile`;
+  `script/lint` and `script/test` each build one with `--no-cache`, and the last
+  stage compiles and depends on both, so `script/cibuild` is one build.
+  `Dockerfile.lint`, `CHECK_EPOCH`, `LINT_EPOCH` and the tests that checked them
+  are gone; `REPO_POLICIES.md` is re-copied.
+
+- 2026-09-23: Stopped `helper fix-missing-thumbnails` retrying files the server
+  always refuses (issue 109). Both thumbnail helpers skip a file another account
+  owns without fetching it. The fixer skips a file whose recorded thumbnail size
+  is 0 or unknown before downloading it, and otherwise tries smaller encodings
+  (720 px quality 50 down to 160 px quality 20) until the encrypted thumbnail is
+  no larger than that size, skipping the file if none fits.
+
+- 2026-09-23: Tested the live-photo hash check's error paths (issue 117). Tests
+  download a live photo whose ZIP names an unknown compression method, one whose
+  ZIP has no image entry and one with no video entry, and check that nothing is
+  stored and the error names the file ID; the unreadable one is not retried.
+
+- 2026-09-23: `quak logout` ends the session on the server (issue 108). It calls
+  `POST /users/logout` through the new `Client.logoutOnServer()`, then deletes
+  `session.json` even when that call fails, says so and exits 1. It prints the
+  account's cache directory and says it still holds decrypted data. The default
+  cache path is now `defaultCacheDirectory()` in the library, shared with
+  `Library.open`.
+
+- 2026-09-23: Fixed the backup's per-collection folders (issue 103). Two files
+  in one collection with the same title, and two collections with the same name,
+  each get their ID added to the name (`IMG_0001 (12345).JPG`, `Trip (10)/`), so
+  none replaces another's symlink or JSON. Each run removes symlinks into
+  `originals/` for files no longer in the collection, and the folders of deleted
+  or renamed collections, leaving anything else in `collections/` alone. The
+  README backup layout states the naming rule.
+
+- 2026-09-23: Checked downloaded originals against their recorded content hash
+  (issue 68). `downloadFile`, which `quak get`, the content cache and backup all
+  use, hashes the decrypted bytes (unkeyed BLAKE2b-512, standard base64) and
+  stores nothing on a mismatch, failing with an error naming the file ID. A live
+  photo ZIP is unpacked as it streams with `fflate` and its image and video
+  hashed separately as `<imageHash>:<videoHash>`. `decryptFile` reads older
+  clients' `imageHash` and `videoHash` fields for live photos. A file with no
+  recorded hash is stored unchecked.
+
+- 2026-09-23: Kept one account's cache from mixing with another's (issue 104).
+  When `metadata.json` in the cache directory was written for a different,
+  non-zero user ID than the client's, `Library.open` deletes it and `mldata/`
+  and starts empty, so the first refresh enumerates from 0. This only happens
+  with `--cache-dir` or an explicit `cacheDirectory`; the default path already
+  includes the user ID. A test opens one account's cache as another account.
+
+- 2026-09-23: `backup-metadata` no longer stops on one failed ML data request
+  (issue 101). Each request of up to 200 files is tried on its own; a failed one
+  is logged, its files are written with the reason in `mlDataError`, and the
+  command exits 1 once the dump is complete. `fetchMLData`, which only this
+  command used, is gone; the command calls `fetchMLDataBatch` per batch.
+- 2026-09-23: Single-sourced the version string (issue 5). `package.json` is the
+  only place it is written: `src/index.ts` imports it for `VERSION` and
+  `bin/quak.ts` passes `VERSION` to commander. tsc copies `package.json` to
+  `dist/package.json`, so the import resolves from the built output too, and
+  `script/build` runs the built CLI with `--version` to prove it. A test checks
+  that `VERSION` and `quak --version` both equal the `package.json` version.
+- 2026-09-23: Tested that `Library.close()` waits for the originals precache
+  (issue 93). The test that holds a precache fetch open while `close()` runs now
+  runs once with only the thumbnail fill and once with only the originals fill,
+  so dropping either wait from `Precache.close()` fails a test.
+- 2026-09-23: Fixed two intermittently failing library tests (issue 90).
+  `Library.close()` now returns a promise that resolves once an in-flight
+  refresh (including its cache write), the ML data fetch and running precache
+  sweeps have finished; the library tests await it, so `afterEach` no longer
+  removes the cache directory while something is still writing into it. The
+  precache test waits for both fills to report "done" instead of for its stub
+  source to be called, which happened before the cache recorded the file.
+- 2026-09-23: Pinned three guards reviewers found untested (issue 89). The
+  download idle deadline's timer is unref'd, so it can never keep the process
+  alive, and a test checks no timer is left after a download completes or fails.
+  A test covers the rejection of `#` in a request path. The EXIF scan compares
+  the `Exif` header only in an APP1 segment of length 8 or more, so it never
+  reads the next segment's bytes, with a test for a short one.
+- 2026-09-23: Made the download deadline an idle deadline (issue 24).
+  `downloadTimeoutMs` now aborts a file or thumbnail download only after no
+  bytes have arrived for that long, default 60 seconds, instead of bounding the
+  whole transfer at 10 minutes, so a slow download that keeps making progress
+  completes. A download that fails before reading the whole body cancels it, so
+  a failed file no longer holds its connection.
+- 2026-09-23: Every `ApiClient` request URL is now built by one function next to
+  the class (issue 18), so a self-hosted `apiOrigin` with a base path keeps it
+  on every request, a path works with or without a leading slash, and query
+  parameters are percent-encoded. A path containing `?` or `#` is rejected with
+  an error instead of being silently cut.
+- 2026-09-23: Made the CLI testable and tested it (issue 12). The command bodies
+  moved from `bin/quak.ts` into `src/cli-commands.ts` as functions that take
+  their options and a context (output streams, session directory, cache
+  directory, session loader) and return an exit code; `bin/quak.ts` only wires
+  them to commander and exits with the code once stdout and stderr have drained,
+  so nothing below it calls `process.exit`. `test/cli/commands.test.ts` drives
+  them with a fake client: session file modes, logout, the missing and corrupt
+  session paths, and the output and exit code of `whoami`, `collections`,
+  `files`, `get`, `get-thumb`, `backup` and `helper list-missing-thumbnails`.
+- 2026-09-23: Hardened the backup tree's atomic copy (issue 22). `copyAtomic`
+  fsyncs its temp file before the rename and the directory after it, through the
+  download writer's `fsyncPath`; each backup run deletes `.quak-backup-*.tmp`
+  files whose process is no longer running. The README backup layout names the
+  temp files and states that the rename replaces a symlink and takes the temp
+  file's permissions. Added tests for a missing and an unwritable destination
+  directory for `downloadFile` and `downloadThumbnail`.
+- 2026-09-23: Hardened the JPEG EXIF scan behind `backup-metadata --exif` (issue
+  11). Every segment length is checked against the remaining bytes and lengths
+  under 2 stop the scan, so a truncated or corrupt original can neither throw
+  nor loop. A malformed or unparseable EXIF segment is recorded as
+  `imageMetadata.exifError`, and a failure to read the original as
+  `imageMetadataError` in the per-file JSON, instead of the field being left
+  out.
+- 2026-09-22: Hardened the retry classifier (issue 80). A `POST` or `PUT` is
+  replayed only when every errno in the cause chain is a connect errno, and it
+  no longer follows redirects. `getRetryOptions()` returns a copy. Tests pin
+  every errno the classifier names, the cause-chain depth limit, cycle
+  termination, and a fresh deadline per attempt for every retrying entry point.
+  The README's endpoint list is the one place that names the requests the replay
+  rule covers.
+- 2026-09-22: Stopped `make test` collecting tests from checkouts nested under
+  `.claude/` (issue 25). vitest ignores `.gitignore` when finding tests, so a
+  nested checkout ran the whole suite again; `vitest.config.ts` now adds
+  `.claude/**` to vitest's default excludes, and
+  `test/packaging/nested-checkout.test.ts` plants a nested checkout in a temp
+  directory and fails if vitest would collect it.
+- 2026-09-22: Dropped the deprecated `@types/libsodium-wrappers-sumo` stub from
+  `devDependencies` (issue 27). It shipped no declarations; the types come from
+  `libsodium-wrappers-sumo` itself. `yarn.lock` regenerated by `yarn remove`.
+- 2026-09-22: Hardened the client session lifecycle (issue 10).
+  `Client.fromJSON` checks every snapshot field and each key's decoded length
+  and names the bad field; `toJSON` reads the token through
+  `ApiClient.getAuthToken` and throws when there is none; `logout` zeroes the
+  key buffers, and `collectionsSince` re-checks for logout after its request so
+  it never decrypts with zeroed keys. The CLI reports a corrupt session file
+  separately from a missing one (`src/cli-session.ts`).
 - 2026-09-22: Sanitized file names taken from server metadata (issue 9). A new
   `src/filename.ts` holds the one sanitizer, used by `quak get`/`get-thumb`
   without `--out`, `downloadFile`/`downloadThumbnail` without `outPath`, and the

bin/quak.ts

@@ -1,218 +1,79 @@
 #!/usr/bin/env node
 
-import { input, password as passwordPrompt } from "@inquirer/prompts";
 import { stdout, stderr } from "node:process";
-import {
-    copyFileSync,
-    existsSync,
-    mkdirSync,
-    readFileSync,
-    writeFileSync,
-} from "node:fs";
-import { join } from "node:path";
+import { input, password } from "@inquirer/prompts";
 import { Command } from "commander";
 import envPaths from "env-paths";
-import { Client, type ClientSnapshot } from "../src/client.js";
 import { init } from "../src/crypto/index.js";
-import { Library, type LibraryClient } from "../src/library/index.js";
 import {
-    fileListRow,
-    fileListLine,
-    originalName,
-    thumbnailName,
-} from "../src/cli-output.js";
-import { freshCollections, freshFiles, freshFile } from "../src/cli-read.js";
-import { runMetadataBackup } from "../src/metadata-backup.js";
-import {
-    listMissingThumbnails,
-    fixMissingThumbnails,
-} from "../src/thumbnails.js";
+    type CliContext,
+    loginCommand,
+    whoamiCommand,
+    logoutCommand,
+    collectionsCommand,
+    filesCommand,
+    getCommand,
+    getThumbCommand,
+    backupMetadataCommand,
+    backupCommand,
+    listMissingThumbnailsCommand,
+    fixMissingThumbnailsCommand,
+} from "../src/cli-commands.js";
+import { run as runCommand } from "../src/cli-run.js";
+import { loadSession } from "../src/cli-session.js";
+import { Client } from "../src/client.js";
+import { VERSION } from "../src/index.js";
 
 const paths = envPaths("quak", { suffix: "" });
-const sessionPath = join(paths.data, "session.json");
-
-const loadSession = (): ClientSnapshot | null => {
-    if (!existsSync(sessionPath)) return null;
-    try {
-        return JSON.parse(readFileSync(sessionPath, "utf-8")) as ClientSnapshot;
-    } catch {
-        return null;
-    }
-};
-
-const saveSession = (snapshot: ClientSnapshot): void => {
-    mkdirSync(paths.data, { recursive: true, mode: 0o700 });
-    writeFileSync(sessionPath, JSON.stringify(snapshot, null, 2), {
-        mode: 0o600,
-    });
-};
-
-const requireSession = (): Client => {
-    const snapshot = loadSession();
-    if (!snapshot) {
-        stderr.write(
-            `Not logged in. Run "quak login" first.\nSession file: ${sessionPath}\n`,
-        );
-        process.exit(1);
-    }
-    return Client.fromJSON(snapshot);
-};
-
-const prompt = async (message: string): Promise<string> => input({ message });
-
-const promptSecret = async (message: string): Promise<string> =>
-    passwordPrompt({ message, mask: true });
 
 const program = new Command();
 
 program
     .name("quak")
     .description("CLI for the Ente end-to-end encrypted photo service")
-    .version("0.0.0")
+    .version(VERSION)
     .option(
         "--cache-dir <path>",
         "Directory for the local metadata/content cache " +
             "(default: the per-user cache directory)",
     );
 
-// The `--cache-dir` global, or undefined to let the library pick its per-user
-// default keyed by the account id.
-const cacheDirOption = (): string | undefined =>
-    program.opts<{ cacheDir?: string }>().cacheDir;
-
-// A library client that omits `fetchMLData`, so the point commands below do not
-// kick the library's background ML backfill: they read metadata, or fetch one
-// file's content, and exit. `backup` and `backup-metadata` handle ML on their
-// own terms. The content source is kept so `get`/`get-thumb`/`--exif` can fetch
-// originals through the on-disk cache.
-const readLibraryClient = (client: Client): LibraryClient => ({
-    whoami: () => client.whoami(),
-    collectionsSince: (args) => client.collectionsSince(args),
-    filesSince: (args) => client.filesSince(args),
-    contentSource: () => client.contentSource(),
+const context = (): CliContext => ({
+    stdout,
+    stderr,
+    sessionDir: paths.data,
+    cacheDir: program.opts<{ cacheDir?: string }>().cacheDir,
+    loadSession,
+    login: (opts) => Client.login(opts),
+    prompt: (message) => input({ message }),
+    promptSecret: (message) => password({ message, mask: true }),
 });
 
-// Open a library for a single point command: the aggressive background precache
-// (issue #48) is off — a one-shot `collections` or `get` must not start
-// downloading the whole account — and the refresh interval is long so no second
-// refresh fires mid-command.
-const openReadLibrary = (client: Client): Promise<Library> =>
-    Library.open({
-        client: readLibraryClient(client),
-        cacheDirectory: cacheDirOption(),
-        refreshIntervalSeconds: 3600,
-        precacheThumbnails: false,
-        precacheOriginals: false,
-    });
-
-// Close the library and exit once stdout/stderr have drained. `process.exit`
-// alone can truncate buffered piped output, and the library keeps the event
-// loop alive with a background refresh, so a plain return could hang; this does
-// neither.
-const finish = (lib: Library | undefined, code: number): void => {
-    lib?.close();
-    const pending = [stdout, stderr].filter((s) => s.writableLength > 0);
-    if (pending.length === 0) {
-        process.exit(code);
-        return;
-    }
-    let remaining = pending.length;
-    for (const s of pending) {
-        s.once("drain", () => {
-            if (--remaining === 0) process.exit(code);
-        });
-    }
-};
+const run = (command: Promise<number>): Promise<void> =>
+    runCommand(command, stdout, stderr, (code) => process.exit(code));
 
 program
     .command("login")
     .description("Log in to an Ente account and save the session")
-    .action(async () => {
-        await init();
-        const email = process.env.QUAK_EMAIL ?? (await prompt("Email"));
-        const password =
-            process.env.QUAK_PASSWORD ?? (await promptSecret("Password"));
-
-        stderr.write("Authenticating...\n");
-        try {
-            const client = await Client.login({
-                email,
-                password,
-                totp: async () => prompt("TOTP code: "),
-                emailOTP: async () => prompt("Email verification code: "),
-            });
-
-            saveSession(client.toJSON());
-            const info = client.whoami();
-            stderr.write(`Logged in as ${info.email} (user ${info.userID})\n`);
-            stderr.write(`Session saved to ${sessionPath}\n`);
-        } catch (err) {
-            stderr.write(
-                `Login failed: ${err instanceof Error ? err.message : err}\n`,
-            );
-            process.exit(1);
-        }
-    });
+    .action(() => run(loginCommand(context())));
 
 program
     .command("whoami")
     .description("Print the logged-in account")
-    .action(() => {
-        const client = requireSession();
-        const info = client.whoami();
-        stdout.write(JSON.stringify(info) + "\n");
-    });
+    .action(() => run(whoamiCommand(context())));
 
 program
     .command("logout")
-    .description("Delete the saved session")
-    .action(async () => {
-        if (existsSync(sessionPath)) {
-            const { unlinkSync } = await import("node:fs");
-            unlinkSync(sessionPath);
-            stderr.write("Session deleted.\n");
-        } else {
-            stderr.write("No session found.\n");
-        }
-    });
+    .description("End the session on the server and delete the saved session")
+    .action(() => run(logoutCommand(context())));
 
 program
     .command("collections")
     .description("List all collections (albums)")
     .option("--json", "Output as JSON array")
-    .action(async (opts: { json?: boolean }) => {
-        await init();
-        const client = requireSession();
-        const lib = await openReadLibrary(client);
-        // Force a server round-trip and list in enumeration order (issue #36
-        // amendment, issue #52): the pre-library CLI printed current state in
-        // this order, not the albums projection's newest-first order.
-        const collections = await freshCollections(lib);
-
-        if (opts.json) {
-            stdout.write(
-                JSON.stringify(
-                    collections.map((c) => ({
-                        id: c.id,
-                        name: c.name,
-                        type: c.type,
-                        ownerID: c.ownerID,
-                        isShared: c.isShared,
-                        updationTime: c.updationTime,
-                    })),
-                    null,
-                    2,
-                ) + "\n",
-            );
-        } else {
-            for (const c of collections) {
-                stdout.write(
-                    `${c.id}\t${c.type}\t${c.name}${c.isShared ? " (shared)" : ""}\n`,
-                );
-            }
-        }
-        finish(lib, 0);
-    });
+    .action((opts: { json?: boolean }) =>
+        run(collectionsCommand(context(), opts)),
+    );
 
 program
     .command("files")
@@ -222,39 +83,9 @@ program
         "Collection ID (from `quak collections`)",
     )
     .option("--json", "Output as JSON array")
-    .action(async (opts: { collection: string; json?: boolean }) => {
-        await init();
-        const client = requireSession();
-        const collectionID = Number(opts.collection);
-        if (!Number.isFinite(collectionID)) {
-            stderr.write("Invalid collection ID\n");
-            process.exit(1);
-        }
-
-        const lib = await openReadLibrary(client);
-        // Force a server round-trip and list in enumeration order (issue #36
-        // amendment, issue #52). Each file prints from its own decrypted
-        // metadata (raw title, microsecond creationTime) via cli-output, and in
-        // the pre-library CLI's enumeration order, not the projection's
-        // newest-first order.
-        const files = await freshFiles(lib, collectionID);
-        if (!files) {
-            stderr.write(`Collection ${collectionID} not found\n`);
-            finish(lib, 1);
-            return;
-        }
-
-        if (opts.json) {
-            stdout.write(
-                JSON.stringify(files.map(fileListRow), null, 2) + "\n",
-            );
-        } else {
-            for (const file of files) {
-                stdout.write(fileListLine(file) + "\n");
-            }
-        }
-        finish(lib, 0);
-    });
+    .action((opts: { collection: string; json?: boolean }) =>
+        run(filesCommand(context(), opts)),
+    );
 
 program
     .command("get")
@@ -262,34 +93,9 @@ program
     .argument("<fileID>", "File ID (from `quak files`)")
     .option("--out <path>", "Output file path")
     .option("--collection <id>", "Accepted for compatibility; ignored")
-    .action(async (fileIDStr: string, opts: { out?: string }) => {
-        await init();
-        const client = requireSession();
-        const fileID = Number(fileIDStr);
-        if (!Number.isFinite(fileID)) {
-            stderr.write("Invalid file ID\n");
-            process.exit(1);
-        }
-
-        const lib = await openReadLibrary(client);
-        // Force a server round-trip so the file resolves against current state
-        // (issue #36 amendment, issue #52).
-        const resolved = await freshFile(lib, fileID);
-        if (!resolved) {
-            stderr.write(`File ${fileID} not found\n`);
-            finish(lib, 1);
-            return;
-        }
-        const { photo, file } = resolved;
-
-        const result = await photo.original();
-        // Default name is the file's own title, as the pre-library CLI used
-        // (not the editedName-preferring projection title) (issue #52).
-        const outPath = opts.out ?? originalName(file);
-        copyFileSync(result.path, outPath);
-        stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
-        finish(lib, 0);
-    });
+    .action((fileID: string, opts: { out?: string }) =>
+        run(getCommand(context(), fileID, opts)),
+    );
 
 program
     .command("get-thumb")
@@ -297,34 +103,9 @@ program
     .argument("<fileID>", "File ID (from `quak files`)")
     .option("--out <path>", "Output file path")
     .option("--collection <id>", "Accepted for compatibility; ignored")
-    .action(async (fileIDStr: string, opts: { out?: string }) => {
-        await init();
-        const client = requireSession();
-        const fileID = Number(fileIDStr);
-        if (!Number.isFinite(fileID)) {
-            stderr.write("Invalid file ID\n");
-            process.exit(1);
-        }
-
-        const lib = await openReadLibrary(client);
-        // Force a server round-trip so the file resolves against current state
-        // (issue #36 amendment, issue #52).
-        const resolved = await freshFile(lib, fileID);
-        if (!resolved) {
-            stderr.write(`File ${fileID} not found\n`);
-            finish(lib, 1);
-            return;
-        }
-        const { photo, file } = resolved;
-
-        const result = await photo.thumbnail();
-        // Default name is thumb_<file's own title>, as the pre-library CLI
-        // used (not the projection title) (issue #52).
-        const outPath = opts.out ?? thumbnailName(file);
-        copyFileSync(result.path, outPath);
-        stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
-        finish(lib, 0);
-    });
+    .action((fileID: string, opts: { out?: string }) =>
+        run(getThumbCommand(context(), fileID, opts)),
+    );
 
 program
     .command("backup-metadata")
@@ -337,16 +118,9 @@ program
         "Download each file and extract full EXIF/IPTC/XMP metadata (slow)",
     )
     .option("--all", "Alias for --exif")
-    .action(async (dir: string, opts: { exif?: boolean; all?: boolean }) => {
-        await init();
-        const client = requireSession();
-        const lib = await openReadLibrary(client);
-        await runMetadataBackup(lib, client, dir, {
-            exif: opts.exif || opts.all,
-            onProgress: (msg) => stderr.write(msg + "\n"),
-        });
-        finish(lib, 0);
-    });
+    .action((dir: string, opts: { exif?: boolean; all?: boolean }) =>
+        run(backupMetadataCommand(context(), dir, opts)),
+    );
 
 program
     .command("backup")
@@ -355,43 +129,9 @@ program
     )
     .argument("<dir>", "Output directory")
     .option("--json", "Print result as JSON instead of human-readable summary")
-    .action(async (dir: string, opts: { json?: boolean }) => {
-        await init();
-        const client = requireSession();
-
-        stderr.write("Starting backup...\n");
-        const lib = await Library.open({
-            client,
-            downloadDirectory: dir,
-            cacheDirectory: cacheDirOption(),
-        });
-        const result = await lib.backup({
-            downloadDirectory: dir,
-            onProgress: (msg) => {
-                if (!opts.json) stderr.write(msg + "\n");
-            },
-        });
-
-        if (opts.json) {
-            stdout.write(JSON.stringify(result, null, 2) + "\n");
-        } else {
-            stderr.write("\n--- Backup complete ---\n");
-            stderr.write(`  Total files: ${result.totalFiles}\n`);
-            stderr.write(`  Downloaded:  ${result.downloaded}\n`);
-            stderr.write(`  Skipped:     ${result.skipped}\n`);
-            stderr.write(`  Failed:      ${result.failed}\n`);
-            if (result.errors.length > 0) {
-                stderr.write("\nFailed files:\n");
-                for (const e of result.errors) {
-                    stderr.write(
-                        `  [${e.collection}] ${e.title} (id ${e.fileID}): ${e.error}\n`,
-                    );
-                }
-            }
-        }
-
-        finish(lib, result.failed > 0 ? 1 : 0);
-    });
+    .action((dir: string, opts: { json?: boolean }) =>
+        run(backupCommand(context(), dir, opts)),
+    );
 
 const helper = program
     .command("helper")
@@ -401,32 +141,9 @@ helper
     .command("list-missing-thumbnails")
     .description("List files whose thumbnails are missing or empty")
     .option("--json", "Output as JSON array")
-    .action(async (opts: { json?: boolean }) => {
-        await init();
-        const client = requireSession();
-        const lib = await openReadLibrary(client);
-        const missing = await listMissingThumbnails(lib, client, (msg) => {
-            if (!opts.json) stderr.write(msg + "\n");
-        });
-
-        if (opts.json) {
-            stdout.write(JSON.stringify(missing, null, 2) + "\n");
-        } else {
-            if (missing.length === 0) {
-                stderr.write("No missing thumbnails found.\n");
-            } else {
-                stderr.write(
-                    `\n${missing.length} file(s) with missing thumbnails:\n`,
-                );
-                for (const m of missing) {
-                    stdout.write(
-                        `${m.fileID}\t${m.title}\t${m.collection}\t${m.reason}\n`,
-                    );
-                }
-            }
-        }
-        finish(lib, 0);
-    });
+    .action((opts: { json?: boolean }) =>
+        run(listMissingThumbnailsCommand(context(), opts)),
+    );
 
 helper
     .command("fix-missing-thumbnails")
@@ -438,65 +155,9 @@ helper
         "Specific file IDs to fix (default: fix all missing)",
     )
     .option("--json", "Output as JSON")
-    .action(async (opts: { file?: string[]; json?: boolean }) => {
-        await init();
-        const client = requireSession();
-        const lib = await openReadLibrary(client);
-
-        let fileIDs: number[];
-        if (opts.file && opts.file.length > 0) {
-            fileIDs = opts.file.map(Number).filter(Number.isFinite);
-        } else {
-            stderr.write("Scanning for missing thumbnails...\n");
-            const missing = await listMissingThumbnails(lib, client, (msg) => {
-                if (!opts.json) stderr.write(msg + "\n");
-            });
-            fileIDs = missing.map((m) => m.fileID);
-            if (fileIDs.length === 0) {
-                stderr.write("No missing thumbnails found.\n");
-                finish(lib, 0);
-                return;
-            }
-            stderr.write(`Found ${fileIDs.length} file(s) to fix.\n`);
-        }
-
-        const results = await fixMissingThumbnails(
-            lib,
-            client,
-            fileIDs,
-            (msg) => {
-                if (!opts.json) stderr.write(msg + "\n");
-            },
-        );
-
-        if (opts.json) {
-            stdout.write(JSON.stringify(results, null, 2) + "\n");
-        } else {
-            const fixed = results.filter((r) => r.status === "fixed").length;
-            const skipped = results.filter(
-                (r) => r.status === "skipped",
-            ).length;
-            const failed = results.filter((r) => r.status === "failed").length;
-            stderr.write(`\n--- Done ---\n`);
-            stderr.write(`  Fixed:   ${fixed}\n`);
-            stderr.write(`  Skipped: ${skipped}\n`);
-            stderr.write(`  Failed:  ${failed}\n`);
-            if (skipped > 0) {
-                stderr.write("\nSkipped (unsupported format):\n");
-                for (const r of results.filter((r) => r.status === "skipped")) {
-                    stderr.write(`  ${r.fileID}\t${r.title}\t${r.reason}\n`);
-                }
-            }
-            if (failed > 0) {
-                stderr.write("\nFailed files:\n");
-                for (const r of results.filter((r) => r.status === "failed")) {
-                    stderr.write(`  ${r.fileID}\t${r.title}\t${r.reason}\n`);
-                }
-            }
-        }
-
-        finish(lib, results.some((r) => r.status === "failed") ? 1 : 0);
-    });
+    .action((opts: { file?: string[]; json?: boolean }) =>
+        run(fixMissingThumbnailsCommand(context(), opts)),
+    );
 
 await init();
-program.parse();
+await program.parseAsync();

package.json

@@ -9,17 +9,23 @@
         "type": "git",
         "url": "https://git.eeqj.de/sneak/quak.git"
     },
+    "private": true,
     "type": "module",
+    "engines": {
+        "node": ">=22"
+    },
     "main": "./dist/src/index.js",
     "types": "./dist/src/index.d.ts",
+    "exports": {
+        ".": {
+            "types": "./dist/src/index.d.ts",
+            "import": "./dist/src/index.js"
+        },
+        "./package.json": "./package.json"
+    },
     "bin": {
         "quak": "./dist/bin/quak.js"
     },
-    "files": [
-        "dist/",
-        "README.md",
-        "LICENSE"
-    ],
     "scripts": {
         "build": "script/build",
         "quak": "node ./dist/bin/quak.js",
@@ -29,7 +35,6 @@
     },
     "devDependencies": {
         "@eslint/js": "9.38.0",
-        "@types/libsodium-wrappers-sumo": "0.8.2",
         "@types/node": "22.18.13",
         "eslint": "9.38.0",
         "prettier": "3.8.1",
@@ -43,6 +48,7 @@
         "env-paths": "4.0.0",
         "exif-reader": "2.0.3",
         "fast-srp-hap": "2.0.4",
+        "fflate": "0.8.3",
         "jpeg-js": "0.4.4",
         "libsodium-wrappers-sumo": "0.8.4"
     }

script/build

@@ -45,10 +45,24 @@ for (const bin of bins) {
 '
 }
 
+# src/index.ts imports ../package.json for the version, which tsc copies to
+# dist/package.json. Running the built CLI proves that import resolves from
+# dist/ and reports the version package.json declares.
+verify_version() {
+    built="$(node dist/bin/quak.js --version)"
+    declared="$(node -p 'require("./package.json").version')"
+    if [ "$built" != "$declared" ]; then
+        echo "build: dist/bin/quak.js reports $built, package.json declares $declared" >&2
+        exit 1
+    fi
+    echo "build: dist/bin/quak.js reports version $built"
+}
+
 main() {
     cd "$ROOT"
     yarn run tsc
     verify_entrypoints
+    verify_version
 }
 
 main "$@"

script/check

@@ -1,19 +1,11 @@
 #!/bin/sh
 # script/check: run all checks (test, lint). Our own extension to
-# scripts-to-rule-them-all. Must not modify any files.
+# scripts-to-rule-them-all. Both are Docker phases. Must not modify any
+# files.
 #
-# The formatting check is part of lint, not a step of its own:
-# script/lint builds Dockerfile.lint, which runs eslint AND
-# `prettier --check .` as build steps. Calling script/fmt-check here as
-# well would run prettier a second time over the same tree for the same
-# verdict — the weaker of the two, since the host toolchain is whatever
-# the working tree happens to have installed while the container's is
-# digest-pinned. script/fmt-check remains a standalone entrypoint for
-# asking the formatting question by itself.
-#
-# script/lint builds Dockerfile.lint, so this script requires docker and
-# must never be run from inside a container: that is why the Dockerfile
-# image runs script/test and script/build rather than this.
+# script/fmt-check is not called here, unlike the template: the lint
+# phase already runs `prettier --check .`, so calling it would run
+# prettier a second time over the same tree for the same verdict.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"

script/cibuild

@@ -1,15 +1,11 @@
 #!/bin/sh
-# script/cibuild: run the CI build, which is both images in a defined order.
-#
-# First script/lint, which builds Dockerfile.lint and is the one and only
-# place linting happens — it goes first so a lint failure is reported before
-# the slower suite runs. Then the Dockerfile image, which runs script/test
-# and script/build. CHECK_EPOCH and LINT_EPOCH differ on every invocation, so
-# neither the linters nor the suite can be served from Docker's cache: a
-# green build here means the checks ran now, not that a previous run was
-# remembered. The layers below the epochs (bootstrap, yarn install) are
-# unaffected and stay cached. A build that omits the arguments fails by
-# design.
+# script/cibuild: run the CI build. The image's last stage depends on the
+# lint and test phases, so this one build runs eslint, prettier and the
+# suite once each and then compiles. Unlike the template it does not run
+# script/check first, which would run lint and the tests a second time.
+# --no-cache for the same reason as script/docker: the gate phases the
+# final stage depends on are RUN steps, and a cached one is a check that
+# did not run.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -17,8 +13,16 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$SCRIPT_DIR/lint"
-    docker build --build-arg CHECK_EPOCH="$(date +%s)" .
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. VERSION is computed here because .dockerignore
+    # excludes .git, so `git describe` in a build stage yields an empty
+    # version without failing.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/docker

@@ -1,10 +1,8 @@
 #!/bin/sh
 # script/docker: build the Docker image tagged with the project name.
 # Identical in all repos; the tag comes from script/projectname.
-# CHECK_EPOCH is passed for the same reason script/cibuild passes it: the
-# Dockerfile refuses to build without it, so that no path to an image can
-# quietly serve the test and build layers from cache. This builds the test
-# and build image only; linting is a separate image, built by script/lint.
+# --no-cache because the gate phases the final stage depends on are RUN
+# steps, and a cached one is a check that did not run.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -12,7 +10,15 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build --build-arg CHECK_EPOCH="$(date +%s)" \
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. VERSION is computed here because .dockerignore
+    # excludes .git, so `git describe` in a build stage yields an empty
+    # version without failing.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
         -t "$("$SCRIPT_DIR/projectname")" .
 }
 

script/lint

@@ -1,24 +1,23 @@
 #!/bin/sh
-# script/lint: run the linters. eslint and prettier are never run against
-# the working tree from here: linting runs via docker only, one way,
-# everywhere — script/lint builds Dockerfile.lint, which COPYs the repo into
-# the pinned node image and runs the linters as build steps. That works even
-# when the docker daemon is remote and bind mounts are impossible.
+# script/lint: run the linter. Linting is a phase of the Dockerfile and
+# this builds that phase alone; the linter is never installed or run on
+# a developer host, where a shared result cache and a host-global lock
+# make its answer untrustworthy.
 #
-# LINT_EPOCH is passed on every invocation because no lint cache is wanted:
-# on an unchanged tree Docker would otherwise serve the linter layers, having
-# linted nothing, and still exit 0. Dockerfile.lint refuses to build without
-# the argument, so no path to a lint result can quietly come from cache.
-#
-# Nothing that runs inside a container may call this script; see the header
-# of Dockerfile.
+# The phase is not the last stage in the file, so it is built only when
+# --target names it. --no-cache because a cached lint layer is a lint
+# that did not run. The tag makes each build replace the previous image
+# instead of leaving a dangling one behind.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build --build-arg LINT_EPOCH="$(date +%s)" -f Dockerfile.lint .
+    docker build --no-cache \
+        --target lint \
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }
 
 main "$@"

script/precommit

@@ -4,17 +4,9 @@
 #
 # Runs lint but deliberately NOT the tests, so the TDD red-phase commit
 # (failing tests, no implementation yet) can land. CI runs
-# script/cibuild, which builds both images and so catches any branch
-# that ships red.
-#
-# The formatting check is still enforced here, because script/lint is a
-# build of Dockerfile.lint and that runs `prettier --check .` as a build
-# step: a badly formatted tree fails this hook, and therefore the
-# commit. Calling script/fmt-check as well would only run prettier a
-# second time over the same tree for the same verdict.
-#
-# script/lint is a docker build (Dockerfile.lint); docker is required to
-# commit, which is the point of linting one way, everywhere.
+# script/cibuild, whose image build includes the test phase, and so
+# catches any branch that ships red. The lint phase includes the
+# prettier check, so a badly formatted tree still fails the commit.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"

script/test

@@ -1,25 +1,19 @@
 #!/bin/sh
-# script/test: run the test suite. Uses `timeout` (GNU coreutils) when
-# available so the run is hard-capped at 30s; on macOS without
-# coreutils the cap is skipped.
+# script/test: run the test suite. Testing is a phase of the Dockerfile
+# and this builds that phase alone, on the same terms as script/lint:
+# --target because a phase that is not the last stage is built only when
+# named, --no-cache because a cached test layer is a test that did not
+# run, and a tag so each build replaces the previous image.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-rerun_verbose() {
-    echo "--- Rerunning with verbose for details ---"
-    yarn run vitest run --reporter=verbose
-    exit 1
-}
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    TIMEOUT="$(command -v timeout 2>/dev/null || command -v gtimeout 2>/dev/null || true)"
-    if [ -n "$TIMEOUT" ]; then
-        "$TIMEOUT" 30s yarn run vitest run --reporter=dot || rerun_verbose
-    else
-        yarn run vitest run --reporter=dot || rerun_verbose
-    fi
+    docker build --no-cache \
+        --target test \
+        -t "$("$SCRIPT_DIR/projectname")-test" .
 }
 
 main "$@"

src/api/client.ts

@@ -19,14 +19,12 @@ const DEFAULT_FILES_ORIGIN = "https://files.ente.io";
 const DEFAULT_THUMBS_ORIGIN = "https://thumbnails.ente.io";
 const CLIENT_PACKAGE = "berlin.sneak.quak";
 
-// Two deadlines rather than one, because a single number cannot serve both
-// jobs. Thirty seconds is generous for a JSON call and short enough that a
-// hung API connection cannot stall a backup for long. A file body is a
-// different shape of problem: the deadline has to cover the whole transfer,
-// which for a large video on a slow link is minutes, so a value sane for JSON
-// would cancel legitimate downloads.
+// Two deadlines of different kinds. `requestTimeoutMs` bounds a whole JSON
+// call. `downloadTimeoutMs` is an idle deadline: a file or thumbnail download
+// is aborted only when no bytes have arrived for that long, so a large video on
+// a slow link that keeps making progress is never cut off.
 export const DEFAULT_REQUEST_TIMEOUT_MS = 30_000;
-export const DEFAULT_DOWNLOAD_TIMEOUT_MS = 600_000;
+export const DEFAULT_DOWNLOAD_TIMEOUT_MS = 60_000;
 
 export interface ApiClientOptions {
     apiOrigin?: string;
@@ -48,18 +46,44 @@ export interface StreamOptions {
     retry?: boolean;
 }
 
-// Enforce a deadline over a response body, not merely over its headers.
+// An abort signal that fires once `ms` pass without a call to `restart`. It
+// aborts with a `TimeoutError`, the same reason `AbortSignal.timeout()` gives,
+// so the retry classifier treats an idle download exactly as it treats any
+// other deadline. `stop` must be called when the download ends. The timer is
+// unref'd, so even one left running never keeps the process alive.
+const idleDeadline = (ms: number) => {
+    const controller = new AbortController();
+    let timer: ReturnType<typeof setTimeout> | undefined;
+    const stop = (): void => clearTimeout(timer);
+    const restart = (): void => {
+        stop();
+        timer = setTimeout(() => {
+            controller.abort(
+                new DOMException(
+                    `download stalled: no bytes received for ${ms} ms`,
+                    "TimeoutError",
+                ),
+            );
+        }, ms);
+        timer.unref();
+    };
+    restart();
+    return { signal: controller.signal, restart, stop };
+};
+
+// Enforce the idle deadline over a response body, not merely over its headers.
 //
 // `getFileStream` returns as soon as headers arrive; the bytes are pulled
 // later, in the download layer. Whether the signal passed to `fetch` also
 // tears down the body afterwards is up to the fetch implementation, so this
 // wrapper makes it a property of quak instead: every read races the signal,
-// and an abort errors the stream with the abort reason — which the retry
-// classifier recognises.
+// each chunk that arrives restarts the deadline, and an abort errors the
+// stream with the abort reason — which the retry classifier recognises.
 const deadlineStream = (
     body: ReadableStream<Uint8Array>,
-    signal: AbortSignal,
+    deadline: ReturnType<typeof idleDeadline>,
 ): ReadableStream<Uint8Array> => {
+    const { signal } = deadline;
     const reader = body.getReader();
     let rejectOnAbort: (reason: unknown) => void = () => undefined;
     const aborted = new Promise<never>((_resolve, reject) => {
@@ -73,7 +97,10 @@ const deadlineStream = (
     const onAbort = (): void => rejectOnAbort(signal.reason);
     if (signal.aborted) onAbort();
     else signal.addEventListener("abort", onAbort, { once: true });
-    const release = (): void => signal.removeEventListener("abort", onAbort);
+    const release = (): void => {
+        deadline.stop();
+        signal.removeEventListener("abort", onAbort);
+    };
 
     return new ReadableStream<Uint8Array>({
         async pull(controller) {
@@ -84,6 +111,7 @@ const deadlineStream = (
                     controller.close();
                     return;
                 }
+                deadline.restart();
                 controller.enqueue(next.value);
             } catch (err) {
                 release();
@@ -98,6 +126,30 @@ const deadlineStream = (
     });
 };
 
+// The one place a request URL is built. `origin` may carry a base path (a
+// self-hosted server behind a prefix) and may end in a slash; `path` may or
+// may not start with one. Query parameters go only through `query`, which
+// percent-encodes them: a `?` or `#` in `path` is an error, because
+// `new URL` would otherwise quietly treat what follows as something else.
+const buildURL = (
+    origin: string,
+    path: string,
+    query?: Record<string, string | number | undefined>,
+): string => {
+    if (path.includes("?") || path.includes("#")) {
+        throw new Error(
+            `request path must not contain "?" or "#"; pass query parameters separately: ${path}`,
+        );
+    }
+    const url = new URL(
+        `${origin.replace(/\/+$/, "")}/${path.replace(/^\/+/, "")}`,
+    );
+    for (const [k, v] of Object.entries(query ?? {})) {
+        if (v !== undefined) url.searchParams.set(k, String(v));
+    }
+    return url.href;
+};
+
 export class ApiClient {
     private readonly apiOrigin: string;
     private readonly isCustomOrigin: boolean;
@@ -139,11 +191,16 @@ export class ApiClient {
         this.token = undefined;
     }
 
+    getAuthToken(): string | undefined {
+        return this.token;
+    }
+
     // The policy this client was configured with, so that a caller wrapping a
     // whole operation in its own `withRetry` — the download layer — runs under
     // the same settings rather than under the library defaults.
+    // A copy, so the caller cannot change this client's settings through it.
     getRetryOptions(): ResolvedRetryOptions {
-        return this.retry;
+        return { ...this.retry };
     }
 
     private headers(extra?: Record<string, string>): Record<string, string> {
@@ -197,22 +254,10 @@ export class ApiClient {
         path: string,
         query?: Record<string, string | number | undefined>,
     ): Promise<T> {
-        const url = new URL(path, this.apiOrigin + "/");
-        // new URL with a base resolves relative paths; ensure we keep the
-        // origin from apiOrigin even when path starts with /
-        url.protocol = new URL(this.apiOrigin).protocol;
-        url.host = new URL(this.apiOrigin).host;
-        url.pathname = path;
-        if (query) {
-            for (const [k, v] of Object.entries(query)) {
-                if (v !== undefined) {
-                    url.searchParams.set(k, String(v));
-                }
-            }
-        }
+        const url = buildURL(this.apiOrigin, path, query);
         // A GET changes nothing, so it is retried under the full policy.
         return withRetry(async () => {
-            const resp = await this._fetch(url.href, {
+            const resp = await this._fetch(url, {
                 method: "GET",
                 headers: this.headers(),
                 signal: AbortSignal.timeout(this.requestTimeoutMs),
@@ -223,16 +268,16 @@ export class ApiClient {
     }
 
     async postJSON<T>(path: string, body: unknown): Promise<T> {
-        const url = `${this.apiOrigin}${path}`;
-        // Idempotency: this reaches `/users/srp/create-session`,
-        // `/users/two-factor/verify` and `/users/ott`, all of which change
-        // server state — verifying a second factor consumes one of a small
-        // number of attempts. So a POST is replayed only on a failure that
-        // establishes no TCP connection to the server ever existed: DNS
-        // produced no address, or the peer refused the connection. A 5xx, a
-        // mid-flight reset, a routing errno (which Linux also delivers on an
-        // established socket) and a timeout are all left to the caller,
-        // because each of them can occur after the server has already acted.
+        const url = buildURL(this.apiOrigin, path);
+        // Not idempotent: a POST is replayed only when `isSafeToReplay`
+        // says no request byte can have reached the server. The endpoints
+        // this covers are listed in the README under "Endpoints used".
+        //
+        // Redirects are not followed. The origin has already received the
+        // request when it answers with one, so a connection refused by the
+        // redirect target would look replay-safe when it is not. The API has
+        // no legitimate redirect, so one surfaces as an `ApiError` with its
+        // 3xx status, which is not retried.
         return withRetry(
             async () => {
                 const resp = await this._fetch(url, {
@@ -241,6 +286,7 @@ export class ApiClient {
                         "Content-Type": "application/json",
                     }),
                     body: JSON.stringify(body),
+                    redirect: "manual",
                     signal: AbortSignal.timeout(this.requestTimeoutMs),
                 });
                 await this.throwIfError(resp);
@@ -255,8 +301,8 @@ export class ApiClient {
         opts?: StreamOptions,
     ): Promise<ReadableStream<Uint8Array>> {
         const url = this.isCustomOrigin
-            ? `${this.apiOrigin}/files/download/${fileID}`
-            : `${this.filesOrigin}/?fileID=${fileID}`;
+            ? buildURL(this.apiOrigin, `/files/download/${fileID}`)
+            : buildURL(this.filesOrigin, "/", { fileID });
         return this.streamRequest(url, opts);
     }
 
@@ -298,10 +344,8 @@ export class ApiClient {
     }
 
     async putJSON<T>(path: string, body: unknown): Promise<T> {
-        const url = `${this.apiOrigin}${path}`;
-        // Same idempotency rule as `postJSON`, for the same reason: this
-        // reaches `/files/thumbnail`, which registers an uploaded thumbnail
-        // against a file.
+        const url = buildURL(this.apiOrigin, path);
+        // Same replay and redirect rules as `postJSON`, for the same reasons.
         return withRetry(
             async () => {
                 const resp = await this._fetch(url, {
@@ -310,6 +354,7 @@ export class ApiClient {
                         "Content-Type": "application/json",
                     }),
                     body: JSON.stringify(body),
+                    redirect: "manual",
                     signal: AbortSignal.timeout(this.requestTimeoutMs),
                 });
                 await this.throwIfError(resp);
@@ -335,8 +380,8 @@ export class ApiClient {
         opts?: StreamOptions,
     ): Promise<ReadableStream<Uint8Array>> {
         const url = this.isCustomOrigin
-            ? `${this.apiOrigin}/files/preview/${fileID}`
-            : `${this.thumbsOrigin}/?fileID=${fileID}`;
+            ? buildURL(this.apiOrigin, `/files/preview/${fileID}`)
+            : buildURL(this.thumbsOrigin, "/", { fileID });
         return this.streamRequest(url, opts);
     }
 
@@ -345,22 +390,27 @@ export class ApiClient {
         opts?: StreamOptions,
     ): Promise<ReadableStream<Uint8Array>> {
         const once = async (): Promise<ReadableStream<Uint8Array>> => {
-            // A fresh deadline per attempt, so a retry gets the whole budget
-            // rather than the remainder of the one that just expired.
-            const signal = AbortSignal.timeout(this.downloadTimeoutMs);
-            const resp = await this._fetch(url, {
-                method: "GET",
-                headers: this.headers(),
-                signal,
-            });
-            await this.throwIfError(resp);
-            if (!resp.body) {
-                // Carries the status, and is not retryable: a response that
-                // arrived without a body is malformed, and asking again
-                // produces the same malformed response.
-                throw new ApiError("response body is null", resp.status);
+            // A fresh deadline per attempt. It also covers the wait for the
+            // headers, when no bytes have arrived either.
+            const deadline = idleDeadline(this.downloadTimeoutMs);
+            try {
+                const resp = await this._fetch(url, {
+                    method: "GET",
+                    headers: this.headers(),
+                    signal: deadline.signal,
+                });
+                await this.throwIfError(resp);
+                if (!resp.body) {
+                    // Carries the status, and is not retryable: a response
+                    // that arrived without a body is malformed, and asking
+                    // again produces the same malformed response.
+                    throw new ApiError("response body is null", resp.status);
+                }
+                return deadlineStream(resp.body, deadline);
+            } catch (err) {
+                deadline.stop();
+                throw err;
             }
-            return deadlineStream(resp.body, signal);
         };
         return opts?.retry === false ? once() : withRetry(once, this.retry);
     }

src/backup.ts

@@ -1,9 +1,11 @@
 // The backup command, rebuilt on the library API (issue #51).
 //
-// `lib.backup()` refreshes the library, then, for every file in scope, gets its
-// original bytes onto disk under `downloadDirectory` and rebuilds the derived
-// views (per-file sidecars, per-collection symlink trees, per-collection JSON)
-// from the model. The on-disk layout is the historical one, unchanged:
+// `lib.backup()` waits for a completed refresh of the library (a failed one
+// fails the backup before any file is touched), then, for every file in scope,
+// gets its original bytes onto disk under `downloadDirectory` and rebuilds the
+// derived views (per-file sidecars, per-collection symlink trees,
+// per-collection JSON) from the model. The on-disk layout is the historical
+// one:
 //
 //     <downloadDirectory>/
 //         originals/<fileID>.<ext>     the decrypted bytes
@@ -12,12 +14,18 @@
 //         collections/<name>.json      per-collection metadata
 //         failures.json                durable ledger of unresolved failures
 //
+// A live photo's original is its image and its video, `<fileID>.<ext>` each
+// with its own extension, and `originals/<fileID>.livephoto.json` naming them;
+// its album folders link both.
+//
 // Crash-safety rests on two properties. Bytes are present-means-complete: an
 // original appears under `originals/` only via the content layer's atomic
 // temp-then-rename, so a file that exists is whole and is never re-fetched — an
 // interrupted run resumes by listing the directory. The derived views hold no
 // unique state, so they are rebuilt every run; that repairs stale sidecars and
-// missing or broken symlinks left by an earlier crash.
+// missing or broken symlinks left by an earlier crash. A rebuild also removes
+// the symlinks into originals/ that no longer belong to an album, and the
+// directories of albums that no longer exist.
 //
 // Resilience (issue #8): no per-file condition aborts the run. A failed
 // download or a failed symlink is caught, recorded in `failures.json` with a
@@ -29,20 +37,27 @@
 // rather than counted forever, which would poison a scheduled backup's exit code.
 
 import {
-    copyFileSync,
     lstatSync,
     mkdirSync,
+    readdirSync,
     readFileSync,
     readlinkSync,
-    renameSync,
+    rmdirSync,
     rmSync,
     statSync,
     symlinkSync,
     writeFileSync,
 } from "node:fs";
-import { basename, dirname, join, relative } from "node:path";
+import { copyFile, rename, rm } from "node:fs/promises";
+import { basename, dirname, extname, join, relative } from "node:path";
 
-import { safeExtension, sanitizeFileName } from "./filename.js";
+import { fsyncPath, removeLeftoverTempFiles } from "./download/index.js";
+import { sanitizeFileName, withExtension } from "./filename.js";
+import {
+    originalName,
+    storedOriginal,
+    writeLivePhoto,
+} from "./library/content.js";
 import type { Collection, EnteFile } from "./model/types.js";
 
 export type ProgressCallback = (message: string) => void;
@@ -91,8 +106,14 @@ export interface BackupLibrary {
     listCollections(): Collection[];
     listFiles(collectionID: number): EnteFile[];
     // Get an original's bytes onto disk through the content cache/pools,
-    // returning where they landed (the cache, or a prior backup).
-    original(fileID: number): Promise<{ path: string }>;
+    // returning where they landed: `destination` when they were fetched now,
+    // otherwise wherever they already were (the cache, or a prior backup). A
+    // live photo lands as its image and its video, fetched now beside
+    // `destination`.
+    original(
+        fileID: number,
+        destination: string,
+    ): Promise<{ path: string; videoPath?: string }>;
     thumbnail(fileID: number): Promise<{ path: string }>;
 }
 
@@ -109,12 +130,6 @@ interface FailureEntry {
 
 const LEDGER_VERSION = 1;
 
-// The originals/ filename for a file: `<id><ext>`, the extension taken from the
-// title (or `.bin`). Matches the content cache's own naming so a present check
-// lines up with what a fetch would write.
-const originalName = (file: EnteFile): string =>
-    `${file.id}${safeExtension(file.metadata.title)}`;
-
 // A regular file with content is treated as complete. A zero-byte file is not:
 // it is the shape an aborted write leaves and must be re-fetched.
 const isPresent = (path: string): boolean => {
@@ -154,8 +169,12 @@ const errorMessage = (err: unknown): string =>
     err instanceof Error ? err.message : String(err);
 
 // Copy bytes into `dest` via a temp file in the same directory plus rename, so
-// `dest` appears only once it is whole ("present means complete").
-const copyAtomic = (src: string, dest: string): void => {
+// `dest` appears only once it is whole ("present means complete"). As in the
+// download writer, the temp file is fsynced before the rename and the directory
+// after it, so a power cut cannot leave a correctly named but short original.
+// The temp name carries this process's ID so a later run can tell a leftover
+// from a copy still in progress (see `removeLeftoverTempFiles`).
+const copyAtomic = async (src: string, dest: string): Promise<void> => {
     if (src === dest) return;
     const tmp = join(
         dirname(dest),
@@ -164,13 +183,43 @@ const copyAtomic = (src: string, dest: string): void => {
             .slice(2)}.tmp`,
     );
     try {
-        copyFileSync(src, tmp);
-        renameSync(tmp, dest);
+        await copyFile(src, tmp);
+        await fsyncPath(tmp);
+        // `rename` replaces the destination's directory entry: an existing
+        // symlink at `dest` is replaced, not followed, and the new file has
+        // the temp file's permissions (copied from `src`).
+        await rename(tmp, dest);
+        await fsyncPath(dirname(dest));
     } finally {
-        rmSync(tmp, { force: true });
+        await rm(tmp, { force: true });
     }
 };
 
+// Put an original the library returned at `dest` in originals/, where a fresh
+// fetch already wrote it. A live photo's image and video go beside `dest`: when
+// they came from the cache they are copied, after removing whatever was at
+// `dest` (an earlier version's ZIP of the two). Then the JSON file naming them
+// is written, which is what makes the live photo count as stored.
+const placeOriginal = async (
+    file: EnteFile,
+    dest: string,
+    got: { path: string; videoPath?: string },
+): Promise<void> => {
+    if (got.videoPath === undefined) {
+        await copyAtomic(got.path, dest);
+        return;
+    }
+    const originalsDir = dirname(dest);
+    const path = join(originalsDir, basename(got.path));
+    const videoPath = join(originalsDir, basename(got.videoPath));
+    if (got.path !== path) {
+        await rm(dest, { force: true });
+        await copyAtomic(got.path, path);
+        await copyAtomic(got.videoPath, videoPath);
+    }
+    await writeLivePhoto(originalsDir, file.id, { path, videoPath });
+};
+
 // Ensure `linkPath` is a symlink to `target`, rebuilding a missing, wrong, or
 // non-symlink entry. Throws on failure (a directory in the way, no permission)
 // so the caller records it and moves on rather than aborting the run.
@@ -187,6 +236,111 @@ const rebuildSymlink = (linkPath: string, target: string): void => {
     symlinkSync(target, linkPath);
 };
 
+// The on-disk names for the entries of one directory, in entry order. Each
+// name is used as is unless another entry would get the same name, ignoring
+// case (two names that differ only in case are one entry on a case-insensitive
+// file system); then every entry sharing it gets ` (<id>)`, before the
+// extension when `beforeExtension` is set. A name with an ID added can match
+// another entry's own name (`IMG (6).JPG`), so this repeats until no name is
+// shared. IDs are stable, so the names are too.
+const uniqueNames = (
+    entries: { id: number; name: string }[],
+    beforeExtension: boolean,
+): string[] => {
+    const withID = (id: number, name: string): string => {
+        const ext = beforeExtension ? extname(name) : "";
+        const stem = name.slice(0, name.length - ext.length);
+        return `${stem} (${id})${ext}`;
+    };
+    const names = entries.map((e) => e.name);
+    const suffixed = new Set<number>();
+    for (;;) {
+        const counts = new Map<string, number>();
+        for (const name of names) {
+            const key = name.toLowerCase();
+            counts.set(key, (counts.get(key) ?? 0) + 1);
+        }
+        let changed = false;
+        for (const [i, { id, name }] of entries.entries()) {
+            if (suffixed.has(i)) continue;
+            if (counts.get(name.toLowerCase()) === 1) continue;
+            names[i] = withID(id, name);
+            suffixed.add(i);
+            changed = true;
+        }
+        if (!changed) return names;
+    }
+};
+
+// The links a file gets in its album's folder: one named after its title, to
+// its original if that is stored. A stored live photo gets two, to its image
+// and its video, each named after the title with that file's extension.
+const linksFor = (
+    file: EnteFile,
+    stored: { path: string; videoPath?: string } | undefined,
+): { id: number; name: string; file: EnteFile; target?: string }[] => {
+    const name = sanitizeFileName(file.metadata.title, `file-${file.id}`);
+    if (stored?.videoPath === undefined) {
+        return [{ id: file.id, name, file, target: stored?.path }];
+    }
+    return [stored.path, stored.videoPath].map((target) => ({
+        id: file.id,
+        name: withExtension(name, extname(target)),
+        file,
+        target,
+    }));
+};
+
+// Remove the symlinks in the album directory `dir` that point into
+// `originalsDir` and are not named in `keep`. Nothing else in the directory
+// is touched: anything else there was put there by the user.
+const removeStaleLinks = (
+    dir: string,
+    keep: Set<string>,
+    originalsDir: string,
+): void => {
+    const target = relative(dir, originalsDir);
+    for (const name of readdirSync(dir)) {
+        if (keep.has(name)) continue;
+        const path = join(dir, name);
+        if (
+            lstatSync(path).isSymbolicLink() &&
+            dirname(readlinkSync(path)) === target
+        ) {
+            rmSync(path);
+        }
+    }
+};
+
+// Remove the directories under `collectionsDir` that an earlier run wrote for
+// an album that is gone or renamed: a directory not named in `current` with a
+// `<name>.json` beside it holding an album ID, which is what a run writes. Its
+// symlinks into originals/ are removed; if that leaves it empty, it and its
+// JSON are deleted, otherwise both stay for what the user put there.
+const removeStaleAlbumDirs = (
+    collectionsDir: string,
+    current: Set<string>,
+    originalsDir: string,
+): void => {
+    for (const entry of readdirSync(collectionsDir, { withFileTypes: true })) {
+        if (!entry.isDirectory() || current.has(entry.name)) continue;
+        const jsonPath = join(collectionsDir, `${entry.name}.json`);
+        try {
+            const album = JSON.parse(readFileSync(jsonPath, "utf-8")) as {
+                id?: unknown;
+            };
+            if (typeof album.id !== "number") continue;
+        } catch {
+            continue;
+        }
+        const dir = join(collectionsDir, entry.name);
+        removeStaleLinks(dir, new Set(), originalsDir);
+        if (readdirSync(dir).length > 0) continue;
+        rmdirSync(dir);
+        rmSync(jsonPath);
+    }
+};
+
 const loadLedger = (path: string): Map<number, FailureEntry> => {
     const ledger = new Map<number, FailureEntry>();
     try {
@@ -254,6 +408,8 @@ export const runBackup = async (
     mkdirSync(originalsDir, { recursive: true });
     mkdirSync(collectionsDir, { recursive: true });
     if (includeThumbnails) mkdirSync(thumbnailsDir, { recursive: true });
+    removeLeftoverTempFiles(originalsDir);
+    removeLeftoverTempFiles(thumbnailsDir);
 
     const ledgerPath = join(downloadDirectory, "failures.json");
     const ledger = loadLedger(ledgerPath);
@@ -261,9 +417,10 @@ export const runBackup = async (
 
     // Collections in scope, and the distinct files across them (a file shared
     // by two albums is one original).
-    const collections = lib
-        .listCollections()
-        .filter((c) => (only ? only.has(c.name) : true));
+    const allCollections = lib.listCollections();
+    const collections = allCollections.filter((c) =>
+        only ? only.has(c.name) : true,
+    );
     const collectionName = new Map<number, string>();
     for (const c of collections) collectionName.set(c.id, c.name);
 
@@ -313,15 +470,21 @@ export const runBackup = async (
     // tree; a present file is left as is.
     if (includeOriginals) {
         for (const [fileID, file] of distinct) {
-            const dest = join(originalsDir, originalName(file));
-            if (isPresent(dest)) {
+            if (storedOriginal(originalsDir, file) !== undefined) {
                 skipped++;
                 continue;
             }
+            const dest = join(originalsDir, originalName(file));
             try {
                 log(`Fetching original ${file.metadata.title} (${fileID})...`);
-                const { path } = await lib.original(fileID);
-                copyAtomic(path, dest);
+                // A fetched original is written straight to `dest` (a live
+                // photo beside it); only one that was already cached elsewhere
+                // is copied.
+                await placeOriginal(
+                    file,
+                    dest,
+                    await lib.original(fileID, dest),
+                );
                 downloaded++;
             } catch (err) {
                 log(
@@ -342,7 +505,7 @@ export const runBackup = async (
             if (isPresent(dest)) continue;
             try {
                 const { path } = await lib.thumbnail(fileID);
-                copyAtomic(path, dest);
+                await copyAtomic(path, dest);
             } catch (err) {
                 recordFailure(
                     file,
@@ -357,38 +520,67 @@ export const runBackup = async (
     // every present original (this repairs stale ones).
     if (includeOriginals) {
         for (const [fileID, file] of distinct) {
-            const orig = join(originalsDir, originalName(file));
-            if (isPresent(orig)) {
+            if (storedOriginal(originalsDir, file) !== undefined) {
                 writeSidecar(join(originalsDir, `${fileID}.json`), file);
             }
         }
     }
 
-    // Then the per-collection symlink trees and JSON.
+    // Then the per-collection symlink trees and JSON. Directory names are
+    // chosen across every album, not just those in scope, so a scoped run
+    // names an album the same as a full one and never takes the directory of
+    // an album it skipped. Stale entries are removed before anything is
+    // rebuilt, so on a case-insensitive file system removing an old name can
+    // never remove the new one.
+    const dirNames = uniqueNames(
+        allCollections.map((c) => ({
+            id: c.id,
+            name: sanitizeFileName(c.name, `collection-${c.id}`),
+        })),
+        false,
+    );
+    const albumDirNames = new Map(
+        allCollections.map((c, i) => [c.id, dirNames[i]!]),
+    );
+    try {
+        removeStaleAlbumDirs(collectionsDir, new Set(dirNames), originalsDir);
+    } catch (err) {
+        log(`FAILED removing old album directories: ${errorMessage(err)}`);
+    }
+
     for (const c of collections) {
-        const colDirName = sanitizeFileName(c.name, `collection-${c.id}`);
+        const colDirName = albumDirNames.get(c.id)!;
         const colDir = join(collectionsDir, colDirName);
         mkdirSync(colDir, { recursive: true });
 
         const files = filesByCollection.get(c.id) ?? [];
-        const metaFiles: { id: number; metadata: EnteFile["metadata"] }[] = [];
-        for (const file of files) {
-            metaFiles.push({ id: file.id, metadata: file.metadata });
-            if (!includeOriginals) continue;
-            const orig = join(originalsDir, originalName(file));
-            if (!isPresent(orig)) continue;
-            const linkName = sanitizeFileName(
-                file.metadata.title,
-                `file-${file.id}`,
-            );
-            const linkPath = join(colDir, linkName);
+        const links = files.flatMap((f) =>
+            linksFor(f, storedOriginal(originalsDir, f)),
+        );
+        const linkNames = uniqueNames(links, true);
+        try {
+            removeStaleLinks(colDir, new Set(linkNames), originalsDir);
+        } catch (err) {
+            log(`FAILED removing old links in ${c.name}: ${errorMessage(err)}`);
+        }
+
+        const metaFiles = files.map((f) => ({
+            id: f.id,
+            metadata: f.metadata,
+        }));
+        for (const [i, link] of links.entries()) {
+            if (!includeOriginals || link.target === undefined) continue;
+            const linkName = linkNames[i]!;
             try {
-                rebuildSymlink(linkPath, relative(colDir, orig));
+                rebuildSymlink(
+                    join(colDir, linkName),
+                    relative(colDir, link.target),
+                );
             } catch (err) {
                 log(
                     `FAILED symlink ${c.name}/${linkName}: ${errorMessage(err)}`,
                 );
-                recordFailure(file, c.name, err);
+                recordFailure(link.file, c.name, err);
             }
         }
 

src/cli-commands.ts

@@ -0,0 +1,559 @@
+// The CLI's commands as plain functions.
+//
+// Each command takes its options and a `CliContext` and resolves to the exit
+// code; a thrown error is left to the caller. Nothing here calls
+// `process.exit`: `bin/quak.ts` wires these to the command line, and `run` in
+// `cli-run.ts` prints a thrown error as one line and exits once output has
+// drained. Output must stay byte-identical (see `cli-output.ts`).
+
+import {
+    copyFileSync,
+    existsSync,
+    mkdirSync,
+    statSync,
+    unlinkSync,
+    writeFileSync,
+} from "node:fs";
+import { extname, join } from "node:path";
+import {
+    type Client,
+    type ClientSnapshot,
+    type LoginOptions,
+} from "./client.js";
+import { init } from "./crypto/index.js";
+import {
+    defaultCacheDirectory,
+    Library,
+    type LibraryClient,
+} from "./library/index.js";
+import {
+    fileListRow,
+    fileListLine,
+    originalName,
+    thumbnailName,
+} from "./cli-output.js";
+import { freshCollections, freshFiles, freshFile } from "./cli-read.js";
+import { withExtension } from "./filename.js";
+import { runMetadataBackup } from "./metadata-backup.js";
+import { listMissingThumbnails, fixMissingThumbnails } from "./thumbnails.js";
+
+export interface CliContext {
+    stdout: { write(text: string): unknown };
+    stderr: { write(text: string): unknown };
+    // Directory holding `session.json`.
+    sessionDir: string;
+    // The `--cache-dir` global, or undefined to let the library pick its
+    // per-user default keyed by the account id.
+    cacheDir?: string;
+    // Reads the session file into a client, or null when there is none. The
+    // CLI passes `loadSession` from `cli-session.ts`; tests pass a fake client.
+    loadSession: (path: string) => Client | null;
+    // Used by `login` only. The CLI passes `Client.login` and terminal
+    // prompts; tests pass fakes.
+    login: (opts: LoginOptions) => Promise<Client>;
+    prompt: (message: string) => Promise<string>;
+    // Like `prompt`, but the answer is masked as it is typed.
+    promptSecret: (message: string) => Promise<string>;
+}
+
+const sessionPath = (ctx: CliContext): string =>
+    join(ctx.sessionDir, "session.json");
+
+// Write the session readable by its owner only, in a directory only its owner
+// can enter.
+export const saveSession = (
+    sessionDir: string,
+    snapshot: ClientSnapshot,
+): void => {
+    mkdirSync(sessionDir, { recursive: true, mode: 0o700 });
+    writeFileSync(
+        join(sessionDir, "session.json"),
+        JSON.stringify(snapshot, null, 2),
+        { mode: 0o600 },
+    );
+};
+
+// The saved client, or undefined after telling the user why there is none.
+const requireSession = (ctx: CliContext): Client | undefined => {
+    let client: Client | null;
+    try {
+        client = ctx.loadSession(sessionPath(ctx));
+    } catch (err) {
+        ctx.stderr.write(
+            `${err instanceof Error ? err.message : err}\n` +
+                `Run "quak logout" and then "quak login" to replace it.\n`,
+        );
+        return undefined;
+    }
+    if (!client) {
+        ctx.stderr.write(
+            `Not logged in. Run "quak login" first.\nSession file: ${sessionPath(ctx)}\n`,
+        );
+        return undefined;
+    }
+    return client;
+};
+
+// A library client that omits `fetchMLData`, so the point commands below do not
+// kick the library's background ML backfill: they read metadata, or fetch one
+// file's content, and exit. `backup` and `backup-metadata` handle ML on their
+// own terms. The content source is kept so `get`/`get-thumb`/`--exif` can fetch
+// originals through the on-disk cache.
+const readLibraryClient = (client: Client): LibraryClient => ({
+    whoami: () => client.whoami(),
+    collectionsSince: (args) => client.collectionsSince(args),
+    filesSince: (args) => client.filesSince(args),
+    contentSource: () => client.contentSource(),
+});
+
+// Open a library for a single point command: the aggressive background precache
+// (issue #48) is off — a one-shot `collections` or `get` must not start
+// downloading the whole account — and the refresh interval is long so no second
+// refresh fires mid-command.
+const openReadLibrary = (ctx: CliContext, client: Client): Promise<Library> =>
+    Library.open({
+        client: readLibraryClient(client),
+        cacheDirectory: ctx.cacheDir,
+        refreshIntervalSeconds: 3600,
+        precacheThumbnails: false,
+        precacheOriginals: false,
+    });
+
+export const loginCommand = async (ctx: CliContext): Promise<number> => {
+    await init();
+    const email = process.env.QUAK_EMAIL ?? (await ctx.prompt("Email"));
+    const password =
+        process.env.QUAK_PASSWORD ?? (await ctx.promptSecret("Password"));
+
+    ctx.stderr.write("Authenticating...\n");
+    try {
+        const client = await ctx.login({
+            email,
+            password,
+            totp: async () => ctx.prompt("TOTP code: "),
+            emailOTP: async () => ctx.prompt("Email verification code: "),
+        });
+
+        saveSession(ctx.sessionDir, client.toJSON());
+        const info = client.whoami();
+        ctx.stderr.write(`Logged in as ${info.email} (user ${info.userID})\n`);
+        ctx.stderr.write(`Session saved to ${sessionPath(ctx)}\n`);
+    } catch (err) {
+        ctx.stderr.write(
+            `Login failed: ${err instanceof Error ? err.message : err}\n`,
+        );
+        return 1;
+    }
+    return 0;
+};
+
+export const whoamiCommand = async (ctx: CliContext): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const info = client.whoami();
+    ctx.stdout.write(JSON.stringify(info) + "\n");
+    return 0;
+};
+
+// Ends the session on the server, then deletes the session file even when that
+// failed, and exits 1 if it did. The cache is left in place; the user is told
+// where it is.
+export const logoutCommand = async (ctx: CliContext): Promise<number> => {
+    const path = sessionPath(ctx);
+    if (!existsSync(path)) {
+        ctx.stderr.write("No session found.\n");
+        return 0;
+    }
+    await init();
+    let cacheDir = ctx.cacheDir;
+    let failure: string | undefined;
+    try {
+        const client = ctx.loadSession(path);
+        if (client) {
+            cacheDir ??= defaultCacheDirectory(client.whoami().userID);
+            await client.logoutOnServer();
+            client.logout();
+        }
+    } catch (err) {
+        failure = err instanceof Error ? err.message : String(err);
+    }
+    unlinkSync(path);
+    if (failure === undefined) {
+        ctx.stderr.write("Session ended on the server.\n");
+    } else {
+        ctx.stderr.write(
+            `Could not end the session on the server: ${failure}\n`,
+        );
+    }
+    ctx.stderr.write("Session deleted.\n");
+    if (cacheDir !== undefined) {
+        ctx.stderr.write(
+            `Cache directory ${cacheDir} still holds decrypted data; delete it to remove that data.\n`,
+        );
+    }
+    return failure === undefined ? 0 : 1;
+};
+
+export const collectionsCommand = async (
+    ctx: CliContext,
+    opts: { json?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Force a server round-trip and list in enumeration order (issue #36
+        // amendment, issue #52): the pre-library CLI printed current state in
+        // this order, not the albums projection's newest-first order.
+        const collections = await freshCollections(lib);
+
+        if (opts.json) {
+            ctx.stdout.write(
+                JSON.stringify(
+                    collections.map((c) => ({
+                        id: c.id,
+                        name: c.name,
+                        type: c.type,
+                        ownerID: c.ownerID,
+                        isShared: c.isShared,
+                        updationTime: c.updationTime,
+                    })),
+                    null,
+                    2,
+                ) + "\n",
+            );
+        } else {
+            for (const c of collections) {
+                ctx.stdout.write(
+                    `${c.id}\t${c.type}\t${c.name}${c.isShared ? " (shared)" : ""}\n`,
+                );
+            }
+        }
+        return 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const filesCommand = async (
+    ctx: CliContext,
+    opts: { collection: string; json?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const collectionID = Number(opts.collection);
+    if (!Number.isFinite(collectionID)) {
+        ctx.stderr.write("Invalid collection ID\n");
+        return 1;
+    }
+
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Force a server round-trip and list in enumeration order (issue #36
+        // amendment, issue #52). Each file prints from its own decrypted
+        // metadata (raw title, microsecond creationTime) via cli-output, and in
+        // the pre-library CLI's enumeration order, not the projection's
+        // newest-first order.
+        const files = await freshFiles(lib, collectionID);
+        if (!files) {
+            ctx.stderr.write(`Collection ${collectionID} not found\n`);
+            return 1;
+        }
+
+        if (opts.json) {
+            ctx.stdout.write(
+                JSON.stringify(files.map(fileListRow), null, 2) + "\n",
+            );
+        } else {
+            for (const file of files) {
+                ctx.stdout.write(fileListLine(file) + "\n");
+            }
+        }
+        return 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const getCommand = async (
+    ctx: CliContext,
+    fileIDStr: string,
+    opts: { out?: string },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const fileID = Number(fileIDStr);
+    if (!Number.isFinite(fileID)) {
+        ctx.stderr.write("Invalid file ID\n");
+        return 1;
+    }
+
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Force a server round-trip so the file resolves against current state
+        // (issue #36 amendment, issue #52).
+        const resolved = await freshFile(lib, fileID);
+        if (!resolved) {
+            ctx.stderr.write(`File ${fileID} not found\n`);
+            return 1;
+        }
+        const { photo, file } = resolved;
+
+        const result = await photo.original();
+        // Default name is the file's own title, as the pre-library CLI used
+        // (not the editedName-preferring projection title) (issue #52).
+        const outPath = opts.out ?? originalName(file);
+        if (result.videoPath === undefined) {
+            copyFileSync(result.path, outPath);
+            ctx.stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
+            return 0;
+        }
+        // A live photo is written as its image and its video, each named after
+        // the title with its own extension, as Ente's clients name them. With
+        // --out, the image goes there and the video beside it.
+        const imageOut =
+            opts.out ?? withExtension(outPath, extname(result.path));
+        const videoOut = withExtension(outPath, extname(result.videoPath));
+        if (imageOut.toLowerCase() === videoOut.toLowerCase()) {
+            ctx.stderr.write(
+                `File ${fileID} is a live photo, and its video would also be written to ${imageOut}\n`,
+            );
+            return 1;
+        }
+        copyFileSync(result.path, imageOut);
+        copyFileSync(result.videoPath, videoOut);
+        ctx.stderr.write(
+            `${result.bytes} bytes -> ${imageOut}\n` +
+                `${statSync(videoOut).size} bytes -> ${videoOut}\n`,
+        );
+        return 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const getThumbCommand = async (
+    ctx: CliContext,
+    fileIDStr: string,
+    opts: { out?: string },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const fileID = Number(fileIDStr);
+    if (!Number.isFinite(fileID)) {
+        ctx.stderr.write("Invalid file ID\n");
+        return 1;
+    }
+
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Force a server round-trip so the file resolves against current state
+        // (issue #36 amendment, issue #52).
+        const resolved = await freshFile(lib, fileID);
+        if (!resolved) {
+            ctx.stderr.write(`File ${fileID} not found\n`);
+            return 1;
+        }
+        const { photo, file } = resolved;
+
+        const result = await photo.thumbnail();
+        // Default name is thumb_<file's own title>, as the pre-library CLI
+        // used (not the projection title) (issue #52).
+        const outPath = opts.out ?? thumbnailName(file);
+        copyFileSync(result.path, outPath);
+        ctx.stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
+        return 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const backupMetadataCommand = async (
+    ctx: CliContext,
+    dir: string,
+    opts: { exif?: boolean; all?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Refresh first so the dump holds current account state, not what the
+        // cache last held; a failed refresh throws.
+        await lib.fresh();
+        const { failedMLBatches } = await runMetadataBackup(lib, client, dir, {
+            exif: opts.exif || opts.all,
+            onProgress: (msg) => ctx.stderr.write(msg + "\n"),
+        });
+        return failedMLBatches > 0 ? 1 : 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const backupCommand = async (
+    ctx: CliContext,
+    dir: string,
+    opts: { json?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+
+    ctx.stderr.write("Starting backup...\n");
+    // The precache is off: the backup fetches what it needs, and must not
+    // also fill the cache with every thumbnail and the recent originals.
+    const lib = await Library.open({
+        client,
+        downloadDirectory: dir,
+        cacheDirectory: ctx.cacheDir,
+        precacheThumbnails: false,
+        precacheOriginals: false,
+    });
+    try {
+        const result = await lib.backup({
+            downloadDirectory: dir,
+            onProgress: (msg) => {
+                if (!opts.json) ctx.stderr.write(msg + "\n");
+            },
+        });
+
+        if (opts.json) {
+            ctx.stdout.write(JSON.stringify(result, null, 2) + "\n");
+        } else {
+            ctx.stderr.write("\n--- Backup complete ---\n");
+            ctx.stderr.write(`  Total files: ${result.totalFiles}\n`);
+            ctx.stderr.write(`  Downloaded:  ${result.downloaded}\n`);
+            ctx.stderr.write(`  Skipped:     ${result.skipped}\n`);
+            ctx.stderr.write(`  Failed:      ${result.failed}\n`);
+            if (result.errors.length > 0) {
+                ctx.stderr.write("\nFailed files:\n");
+                for (const e of result.errors) {
+                    ctx.stderr.write(
+                        `  [${e.collection}] ${e.title} (id ${e.fileID}): ${e.error}\n`,
+                    );
+                }
+            }
+        }
+
+        return result.failed > 0 ? 1 : 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const listMissingThumbnailsCommand = async (
+    ctx: CliContext,
+    opts: { json?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Refresh first so files added since the cache was written are
+        // checked; a failed refresh throws.
+        await lib.fresh();
+        const missing = await listMissingThumbnails(lib, client, (msg) => {
+            if (!opts.json) ctx.stderr.write(msg + "\n");
+        });
+
+        if (opts.json) {
+            ctx.stdout.write(JSON.stringify(missing, null, 2) + "\n");
+        } else {
+            if (missing.length === 0) {
+                ctx.stderr.write("No missing thumbnails found.\n");
+            } else {
+                ctx.stderr.write(
+                    `\n${missing.length} file(s) with missing thumbnails:\n`,
+                );
+                for (const m of missing) {
+                    ctx.stdout.write(
+                        `${m.fileID}\t${m.title}\t${m.collection}\t${m.reason}\n`,
+                    );
+                }
+            }
+        }
+        return 0;
+    } finally {
+        await lib.close();
+    }
+};
+
+export const fixMissingThumbnailsCommand = async (
+    ctx: CliContext,
+    opts: { file?: string[]; json?: boolean },
+): Promise<number> => {
+    await init();
+    const client = requireSession(ctx);
+    if (!client) return 1;
+    const lib = await openReadLibrary(ctx, client);
+    try {
+        // Refresh first so files added since the cache was written are found;
+        // a failed refresh throws.
+        await lib.fresh();
+        let fileIDs: number[];
+        if (opts.file && opts.file.length > 0) {
+            fileIDs = opts.file.map(Number).filter(Number.isFinite);
+        } else {
+            ctx.stderr.write("Scanning for missing thumbnails...\n");
+            const missing = await listMissingThumbnails(lib, client, (msg) => {
+                if (!opts.json) ctx.stderr.write(msg + "\n");
+            });
+            fileIDs = missing.map((m) => m.fileID);
+            if (fileIDs.length === 0) {
+                ctx.stderr.write("No missing thumbnails found.\n");
+                return 0;
+            }
+            ctx.stderr.write(`Found ${fileIDs.length} file(s) to fix.\n`);
+        }
+
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            fileIDs,
+            (msg) => {
+                if (!opts.json) ctx.stderr.write(msg + "\n");
+            },
+        );
+
+        if (opts.json) {
+            ctx.stdout.write(JSON.stringify(results, null, 2) + "\n");
+        } else {
+            const fixed = results.filter((r) => r.status === "fixed").length;
+            const skipped = results.filter(
+                (r) => r.status === "skipped",
+            ).length;
+            const failed = results.filter((r) => r.status === "failed").length;
+            ctx.stderr.write(`\n--- Done ---\n`);
+            ctx.stderr.write(`  Fixed:   ${fixed}\n`);
+            ctx.stderr.write(`  Skipped: ${skipped}\n`);
+            ctx.stderr.write(`  Failed:  ${failed}\n`);
+            if (skipped > 0) {
+                ctx.stderr.write("\nSkipped:\n");
+                for (const r of results.filter((r) => r.status === "skipped")) {
+                    ctx.stderr.write(
+                        `  ${r.fileID}\t${r.title}\t${r.reason}\n`,
+                    );
+                }
+            }
+            if (failed > 0) {
+                ctx.stderr.write("\nFailed files:\n");
+                for (const r of results.filter((r) => r.status === "failed")) {
+                    ctx.stderr.write(
+                        `  ${r.fileID}\t${r.title}\t${r.reason}\n`,
+                    );
+                }
+            }
+        }
+
+        return results.some((r) => r.status === "failed") ? 1 : 0;
+    } finally {
+        await lib.close();
+    }
+};

src/cli-run.ts

@@ -0,0 +1,36 @@
+// Runs one CLI command for `bin/quak.ts` and exits with its code.
+
+import type { Writable } from "node:stream";
+
+// Run a command and exit with its code once stdout/stderr have drained.
+// Exiting before the drain can truncate piped output, and the library can keep
+// the event loop alive after a command returns, so a plain return could hang.
+// An error the command throws is printed as one `quak: MESSAGE` line, without
+// the stack trace, and exits 1.
+export const run = async (
+    command: Promise<number>,
+    stdout: Writable,
+    stderr: Writable,
+    exit: (code: number) => void,
+): Promise<void> => {
+    let code: number;
+    try {
+        code = await command;
+    } catch (err) {
+        stderr.write(
+            `quak: ${err instanceof Error ? err.message : String(err)}\n`,
+        );
+        code = 1;
+    }
+    const pending = [stdout, stderr].filter((s) => s.writableLength > 0);
+    if (pending.length === 0) {
+        exit(code);
+        return;
+    }
+    let remaining = pending.length;
+    for (const s of pending) {
+        s.once("drain", () => {
+            if (--remaining === 0) exit(code);
+        });
+    }
+};

src/cli-session.ts

@@ -0,0 +1,26 @@
+// How the CLI reads its saved session file back into a `Client`.
+//
+// A missing file means "not logged in" and returns null. A file that exists but
+// cannot be read back into a client (bad JSON, a missing field, a key of the
+// wrong length) throws an error saying the session file is corrupt, so the CLI
+// can tell the user which of the two it is. Needs `init()` first.
+
+import { existsSync, readFileSync } from "node:fs";
+import type { ApiClientOptions } from "./api/client.js";
+import { Client } from "./client.js";
+
+export const loadSession = (
+    path: string,
+    apiOptions?: ApiClientOptions,
+): Client | null => {
+    if (!existsSync(path)) return null;
+    try {
+        return Client.fromJSON(
+            JSON.parse(readFileSync(path, "utf-8")),
+            apiOptions,
+        );
+    } catch (err) {
+        const reason = err instanceof Error ? err.message : String(err);
+        throw new Error(`Session file ${path} is corrupt: ${reason}`);
+    }
+};

src/client.ts

@@ -125,18 +125,57 @@ export class Client {
         );
     }
 
-    static fromJSON(
-        snapshot: ClientSnapshot,
-        apiOptions?: ApiClientOptions,
-    ): Client {
-        const api = new ApiClient({ ...apiOptions, authToken: snapshot.token });
+    // Restore a client from a `toJSON()` snapshot. The snapshot usually comes
+    // straight from `JSON.parse` of a file on disk, so every field is checked
+    // before use; a bad one throws an error naming it. Needs `init()` first.
+    static fromJSON(snapshot: unknown, apiOptions?: ApiClientOptions): Client {
+        const invalid = (field: string, problem: string): Error =>
+            new Error(`Invalid session data: ${field} ${problem}`);
+
+        if (typeof snapshot !== "object" || snapshot === null) {
+            throw new Error("Invalid session data: not a JSON object");
+        }
+        const s = snapshot as Record<string, unknown>;
+        for (const field of ["email", "token"]) {
+            if (typeof s[field] !== "string" || s[field] === "") {
+                throw invalid(field, "must be a non-empty string");
+            }
+        }
+        if (!Number.isInteger(s.userID)) {
+            throw invalid("userID", "must be an integer");
+        }
+        const key = (field: string): Uint8Array => {
+            const value = s[field];
+            if (typeof value !== "string") {
+                throw invalid(field, "must be a base64 string");
+            }
+            let bytes: Uint8Array;
+            try {
+                bytes = fromBase64(value);
+            } catch {
+                throw invalid(field, "is not valid base64");
+            }
+            // The master key (secretbox) and the key pair (box) are all 32 bytes.
+            if (bytes.length !== 32) {
+                throw invalid(
+                    field,
+                    `must decode to 32 bytes, got ${bytes.length}`,
+                );
+            }
+            return bytes;
+        };
+
+        const api = new ApiClient({
+            ...apiOptions,
+            authToken: s.token as string,
+        });
         return new Client(
             api,
-            snapshot.email,
-            snapshot.userID,
-            fromBase64(snapshot.masterKey),
-            fromBase64(snapshot.secretKey),
-            fromBase64(snapshot.publicKey),
+            s.email as string,
+            s.userID as number,
+            key("masterKey"),
+            key("secretKey"),
+            key("publicKey"),
         );
     }
 
@@ -164,19 +203,37 @@ export class Client {
 
     toJSON(): ClientSnapshot {
         this.assertLoggedIn();
+        const token = this.api.getAuthToken();
+        if (!token) {
+            throw new Error("Cannot serialize client: it has no auth token");
+        }
         return {
             email: this.email,
             userID: this.userID,
-            token: this.api["token"]!,
+            token,
             masterKey: toBase64(this.masterKey),
             secretKey: toBase64(this.secretKey),
             publicKey: toBase64(this.publicKey),
         };
     }
 
+    // Ends this client's session on the server (`POST /users/logout`), so the
+    // token stops working everywhere, including in any saved copy of it. This
+    // client is left as it was; call `logout()` to clear it.
+    async logoutOnServer(): Promise<void> {
+        this.assertLoggedIn();
+        await this.api.postJSON("/users/logout", {});
+    }
+
+    // Zeroes the key buffers in place, so any copy of the reference held
+    // elsewhere is wiped too. Every method checks `assertLoggedIn` before
+    // touching the keys, so nothing decrypts with the zeroed keys.
     logout(): void {
         this.loggedOut = true;
         this.api.clearAuthToken();
+        this.masterKey.fill(0);
+        this.secretKey.fill(0);
+        this.publicKey.fill(0);
     }
 
     // Enumerate collections changed since `sinceTime`. Live collections are
@@ -192,6 +249,8 @@ export class Client {
         const { collections: raws } = await this.api.getJSON<{
             collections: RawCollection[];
         }>("/collections/v2", { sinceTime: args.sinceTime });
+        // logout() may have zeroed the keys while the request was in flight.
+        this.assertLoggedIn();
 
         const collections: Collection[] = [];
         const deleted: number[] = [];

src/crypto/hash.ts

@@ -0,0 +1,22 @@
+import sodium, { type StateAddress } from "libsodium-wrappers-sumo";
+import { toBase64 } from "./encoding.js";
+
+// The content hash an uploading client records in a file's metadata: unkeyed
+// BLAKE2b with a 64-byte output over the original's bytes, fed in chunks, as
+// standard base64 with padding. Named after the upstream client's functions.
+// The output length is read at call time for the same reason as
+// `streamTagFinal` in stream.ts: libsodium sets its constants only once ready.
+
+export const chunkHashInit = (): StateAddress =>
+    sodium.crypto_generichash_init(null, sodium.crypto_generichash_BYTES_MAX);
+
+export const chunkHashUpdate = (state: StateAddress, chunk: Uint8Array): void =>
+    sodium.crypto_generichash_update(state, chunk);
+
+export const chunkHashFinal = (state: StateAddress): string =>
+    toBase64(
+        sodium.crypto_generichash_final(
+            state,
+            sodium.crypto_generichash_BYTES_MAX,
+        ),
+    );

src/crypto/index.ts

@@ -7,6 +7,7 @@ export {
 } from "./encoding.js";
 export { deriveKEK, deriveLoginSubkey } from "./kdf.js";
 export { decryptBox, decryptSealed } from "./box.js";
+export { chunkHashFinal, chunkHashInit, chunkHashUpdate } from "./hash.js";
 export {
     decryptBlob,
     encryptBlob,

src/download/index.ts

@@ -1,8 +1,13 @@
-import { randomUUID } from "node:crypto";
+import { randomBytes } from "node:crypto";
+import { readdirSync, rmSync } from "node:fs";
 import { open, rename, rm } from "node:fs/promises";
 import type { FileHandle } from "node:fs/promises";
 import { dirname, join } from "node:path";
+import { Unzip, UnzipInflate } from "fflate";
 import {
+    chunkHashFinal,
+    chunkHashInit,
+    chunkHashUpdate,
     fromBase64,
     initStreamPull,
     pullStreamChunk,
@@ -11,14 +16,18 @@ import {
     streamTagFinal,
 } from "../crypto/index.js";
 import { TruncatedStreamError } from "../errors.js";
-import { sanitizeFileName } from "../filename.js";
+import { safeExtension, sanitizeFileName, withExtension } from "../filename.js";
 import { withRetry } from "../retry.js";
 import type { ApiClient } from "../api/client.js";
 import type { EnteFile } from "../model/types.js";
 
 export interface DownloadResult {
+    // Where the file was written. A live photo is written as two files, its
+    // image here and its video at `videoPath` (see `decryptLivePhoto`).
     path: string;
+    // The decrypted length; for a live photo, that of the ZIP it arrives as.
     bytesWritten: number;
+    videoPath?: string;
 }
 
 // Fired as decrypted plaintext accumulates, with the running total of
@@ -40,9 +49,9 @@ const ENC_CHUNK_SIZE = STREAM_CHUNK_SIZE + STREAM_CHUNK_OVERHEAD;
 // new: a body cut short still decrypts and authenticates up to its last whole
 // chunk, so the absence of TAG_FINAL is the sole evidence it was cut short, and
 // this throws rather than let a caller keep a short file. The sink has already
-// seen those chunks by then; the caller (`decryptToTemp`) stages them in a temp
-// file that is renamed into place only on a clean return, so a throw leaves
-// nothing on disk.
+// seen those chunks by then; the callers (`decryptToTemp`, `decryptLivePhoto`)
+// stage them in temp files that are renamed into place only on a clean return,
+// so a throw leaves nothing on disk.
 const streamDecrypt = async (
     stream: ReadableStream<Uint8Array>,
     header: Uint8Array,
@@ -98,47 +107,53 @@ const streamDecrypt = async (
         onProgress?.(totalPlain);
     };
 
-    for (;;) {
-        const { done, value } = await reader.read();
-        if (value && value.length > 0) {
-            pending.push(value);
-            pendingBytes += value.length;
-        }
+    try {
+        for (;;) {
+            const { done, value } = await reader.read();
+            if (value && value.length > 0) {
+                pending.push(value);
+                pendingBytes += value.length;
+            }
 
-        while (pendingBytes >= ENC_CHUNK_SIZE) {
-            const encChunk = takeContiguous(ENC_CHUNK_SIZE);
-            // A whole chunk that fails to authenticate while the stream carries
-            // on is corruption, not truncation; that error propagates unchanged.
-            const { plaintext, tag } = pullStreamChunk(state, encChunk);
-            await consume(plaintext, tag);
-        }
+            while (pendingBytes >= ENC_CHUNK_SIZE) {
+                const encChunk = takeContiguous(ENC_CHUNK_SIZE);
+                // A whole chunk that fails to authenticate while the stream
+                // carries on is corruption, not truncation; that error
+                // propagates unchanged.
+                const { plaintext, tag } = pullStreamChunk(state, encChunk);
+                await consume(plaintext, tag);
+            }
 
-        if (done) {
-            if (pendingBytes > 0) {
-                const buffer = takeContiguous(pendingBytes);
-                // Whatever is left over once every whole chunk has been
-                // consumed must be the stream's final chunk, and a final
-                // chunk that actually arrived in full authenticates. If it
-                // does not, the body stopped part-way through a chunk — the
-                // ordinary shape of a dropped connection. Poly1305 cannot
-                // tell a partial chunk from a corrupt one, so this is
-                // reported as the truncation it almost always is, with the
-                // authentication failure kept as the error's cause. Only the
-                // pull is guarded: a sink failure on a chunk that did
-                // authenticate is a disk error, not a truncation.
-                let pulled;
-                try {
-                    pulled = pullStreamChunk(state, buffer);
-                } catch (err) {
-                    throw new TruncatedStreamError(
-                        `download: stream truncated: response body ended with ${buffer.length} trailing bytes that did not authenticate as a final chunk (transfer stopped mid-chunk, or the data is corrupt)`,
-                        { cause: err },
-                    );
+            if (done) {
+                if (pendingBytes > 0) {
+                    const buffer = takeContiguous(pendingBytes);
+                    // Whatever is left over once every whole chunk has been
+                    // consumed must be the stream's final chunk, and a final
+                    // chunk that actually arrived in full authenticates. If
+                    // it does not, the body stopped part-way through a chunk
+                    // — the ordinary shape of a dropped connection. Poly1305
+                    // cannot tell a partial chunk from a corrupt one, so this
+                    // is reported as the truncation it almost always is, with
+                    // the authentication failure kept as the error's cause.
+                    // Only the pull is guarded: a sink failure on a chunk
+                    // that did authenticate is a disk error, not a
+                    // truncation.
+                    let pulled;
+                    try {
+                        pulled = pullStreamChunk(state, buffer);
+                    } catch (err) {
+                        throw new TruncatedStreamError(
+                            `download: stream truncated: response body ended with ${buffer.length} trailing bytes that did not authenticate as a final chunk (transfer stopped mid-chunk, or the data is corrupt)`,
+                            { cause: err },
+                        );
+                    }
+                    await consume(pulled.plaintext, pulled.tag);
                 }
-                await consume(pulled.plaintext, pulled.tag);
+                break;
             }
-            break;
         }
+    } finally {
+        reader.releaseLock();
     }
 
     // Only the last chunk of a secretstream carries TAG_FINAL. Everything a
@@ -158,6 +173,57 @@ const streamDecrypt = async (
     return totalPlain;
 };
 
+// Fsync a file or a directory, so its contents (for a directory, its entries)
+// are on stable storage. Exported for the backup tree's copy, which needs the
+// same durability as the writer below.
+export const fsyncPath = async (path: string): Promise<void> => {
+    const handle = await open(path, "r");
+    try {
+        await handle.sync();
+    } finally {
+        await handle.close();
+    }
+};
+
+// A process-ID check: signal 0 delivers nothing and only reports whether the
+// process exists. EPERM means it exists but belongs to another user.
+const isRunning = (pid: number): boolean => {
+    try {
+        process.kill(pid, 0);
+        return true;
+    } catch (err) {
+        return (err as NodeJS.ErrnoException).code === "EPERM";
+    }
+};
+
+// Delete the temp files a killed process left in `dir`: the writer's
+// `.quak-<pid>-<random>.tmp` and the backup copy's
+// `.quak-backup-<name>-<pid>-<random>.tmp`. Only files whose process is no
+// longer running are removed, so another process writing into the same
+// directory keeps its own. A reused process ID can only keep a leftover a while
+// longer, never remove a live one.
+export const removeLeftoverTempFiles = (dir: string): void => {
+    let names: string[];
+    try {
+        names = readdirSync(dir);
+    } catch {
+        return;
+    }
+    for (const name of names) {
+        const match = /^\.quak-(?:.*-)?(\d+)-[0-9a-z]*\.tmp$/.exec(name);
+        if (match && !isRunning(Number(match[1]))) {
+            rmSync(join(dir, name), { force: true });
+        }
+    }
+};
+
+// A new temp file name in `dir`. The random suffix keeps concurrent downloads
+// of the same destination from stepping on each other's temporary file; the
+// process ID lets `removeLeftoverTempFiles` tell a leftover from a write in
+// progress.
+const tempPathIn = (dir: string): string =>
+    join(dir, `.quak-${process.pid}-${randomBytes(16).toString("hex")}.tmp`);
+
 // Stage a write to `destination` atomically and durably, then rename it into
 // place. `fill` writes the contents into the open temp file handle — either the
 // whole buffer at once (`writeAtomic`) or chunk by chunk as they decrypt
@@ -182,9 +248,7 @@ const stageAtomic = async (
     fill: (handle: FileHandle) => Promise<void>,
 ): Promise<void> => {
     const dir = dirname(destination);
-    // The random suffix keeps concurrent downloads of the same destination
-    // from stepping on each other's temporary file.
-    const tmpPath = join(dir, `.quak-${randomUUID()}.tmp`);
+    const tmpPath = tempPathIn(dir);
     try {
         const handle = await open(tmpPath, "w");
         try {
@@ -193,16 +257,15 @@ const stageAtomic = async (
         } finally {
             await handle.close();
         }
+        // `rename` replaces the destination's directory entry rather than
+        // writing through it: an existing symlink at `destination` is
+        // replaced, not followed, and the new file has the temp file's
+        // permissions, not those of the file it replaced.
         await rename(tmpPath, destination);
         // Fsync the directory so the rename itself survives a crash: renaming
         // over a synced temp file still leaves the new directory entry in the
         // page cache until the directory is synced.
-        const dirHandle = await open(dir, "r");
-        try {
-            await dirHandle.sync();
-        } finally {
-            await dirHandle.close();
-        }
+        await fsyncPath(dir);
     } catch (err) {
         // Best-effort cleanup. A failure to remove the temporary file must
         // never replace the error that actually explains what went wrong.
@@ -220,19 +283,36 @@ export const writeAtomic = async (
 ): Promise<void> =>
     stageAtomic(destination, (handle) => handle.writeFile(plaintext));
 
+// Refuse an original whose bytes do not hash to what its uploader recorded.
+// The error is not retried.
+const checkHash = (file: EnteFile, actual: string): void => {
+    if (actual !== file.metadata.hash) {
+        throw new Error(
+            `download: file ${file.id}: content hash ${actual} does not match the hash its uploader recorded, ${file.metadata.hash}`,
+        );
+    }
+};
+
 // Decrypt `stream` straight to `destination`, one plaintext chunk at a time,
 // under the atomic writer's temp-then-rename discipline. Memory stays bounded
 // by the chunk size: each decrypted chunk is written to the temp file and
 // dropped. The rename happens only after the stream authenticates as terminated
 // on TAG_FINAL; a truncated stream throws and leaves the destination untouched.
 // Returns the plaintext length written.
+//
+// `original` is the file whose original this is (none for a thumbnail, which
+// has no recorded hash). When its metadata has a hash, the decrypted bytes are
+// hashed as they stream and must match it, or nothing is stored.
 const decryptToTemp = async (
     destination: string,
     stream: ReadableStream<Uint8Array>,
     header: Uint8Array,
     key: Uint8Array,
     onProgress?: ProgressCallback,
+    original?: EnteFile,
 ): Promise<number> => {
+    const hash =
+        original?.metadata.hash === undefined ? undefined : chunkHashInit();
     let bytesWritten = 0;
     await stageAtomic(destination, async (handle) => {
         bytesWritten = await streamDecrypt(
@@ -240,14 +320,166 @@ const decryptToTemp = async (
             header,
             key,
             async (plaintext) => {
+                if (hash !== undefined) chunkHashUpdate(hash, plaintext);
                 await handle.write(plaintext);
             },
             onProgress,
         );
+        if (original !== undefined && hash !== undefined) {
+            checkHash(original, chunkHashFinal(hash));
+        }
     });
     return bytesWritten;
 };
 
+// One of the two parts of a live photo being unpacked: the ZIP entry whose
+// name starts with `kind`, written to its own temp file.
+interface LivePhotoPart {
+    kind: "image" | "video";
+    tmpPath: string;
+    handle: FileHandle;
+    hash: ReturnType<typeof chunkHashInit>;
+    // Decompressed bytes not yet written.
+    pending: Uint8Array[];
+    // The entry's extension, set once all of the entry has been read.
+    ext?: string;
+}
+
+const openPart = async (
+    kind: "image" | "video",
+    dir: string,
+): Promise<LivePhotoPart> => {
+    const tmpPath = tempPathIn(dir);
+    const handle = await open(tmpPath, "w");
+    return { kind, tmpPath, handle, hash: chunkHashInit(), pending: [] };
+};
+
+// A live photo arrives as a ZIP of its image and its video. Ente's clients
+// name the entries `image.<ext>` and `video.<ext>`, and like the upstream
+// client's decoder this takes the first entries whose names start with `image`
+// and `video`. It is written unpacked: each part is named `destination` with
+// the extension replaced by its own entry's, and the two must differ ignoring
+// case. When the file records a hash, `<imageHash>:<videoHash>` must match it,
+// each over that part's own bytes. Only then is whatever was at `destination`
+// removed and the image, then the video, renamed into place; on any failure
+// neither is stored.
+//
+// The ZIP is chosen by its uploader and may expand enormously, so each part is
+// written as it decompresses and never held. fflate's `Unzip` inflates each
+// push in one piece before `push` returns, and deflate expands at most about
+// 1000-fold, so the ZIP is pushed in 4 KiB slices, keeping each decompressed
+// piece near 4 MiB, one plaintext chunk, and each piece is written before the
+// next slice is pushed. Every entry is started, even one that is not kept,
+// because fflate keeps an unstarted entry's data in memory.
+const decryptLivePhoto = async (
+    destination: string,
+    stream: ReadableStream<Uint8Array>,
+    header: Uint8Array,
+    key: Uint8Array,
+    onProgress: ProgressCallback | undefined,
+    file: EnteFile,
+): Promise<DownloadResult> => {
+    const sliceSize = 4096;
+    const dir = dirname(destination);
+    const fail = (message: string, cause?: unknown): Error =>
+        new Error(`download: file ${file.id}: ${message}`, { cause });
+    const parts: LivePhotoPart[] = [];
+    try {
+        const image = await openPart("image", dir);
+        parts.push(image);
+        const video = await openPart("video", dir);
+        parts.push(video);
+
+        const claimed = new Set<LivePhotoPart>();
+        const unzip = new Unzip((entry) => {
+            const part = parts.find(
+                (p) => !claimed.has(p) && entry.name.startsWith(p.kind),
+            );
+            if (part !== undefined) claimed.add(part);
+            entry.ondata = (err, data, final) => {
+                if (err) throw err;
+                if (part === undefined) return;
+                chunkHashUpdate(part.hash, data);
+                part.pending.push(data);
+                if (final) part.ext = safeExtension(entry.name);
+            };
+            entry.start();
+        });
+        unzip.register(UnzipInflate);
+        const push = async (
+            data: Uint8Array,
+            final: boolean,
+        ): Promise<void> => {
+            // fflate reports a bad ZIP by throwing, sometimes a TypeError,
+            // which the retry would take for a network failure; a bad ZIP is
+            // never retried.
+            try {
+                unzip.push(data, final);
+            } catch (err) {
+                throw fail("live photo is not a readable ZIP", err);
+            }
+            for (const part of parts) {
+                for (const piece of part.pending)
+                    await part.handle.write(piece);
+                part.pending = [];
+            }
+        };
+
+        const bytesWritten = await streamDecrypt(
+            stream,
+            header,
+            key,
+            async (plaintext) => {
+                for (let i = 0; i < plaintext.length; i += sliceSize) {
+                    await push(plaintext.subarray(i, i + sliceSize), false);
+                }
+            },
+            onProgress,
+        );
+        await push(new Uint8Array(0), true);
+
+        if (image.ext === undefined || video.ext === undefined) {
+            throw fail(
+                "live photo ZIP does not hold both an image and a video",
+            );
+        }
+        if (file.metadata.hash !== undefined) {
+            checkHash(
+                file,
+                `${chunkHashFinal(image.hash)}:${chunkHashFinal(video.hash)}`,
+            );
+        }
+        if (image.ext.toLowerCase() === video.ext.toLowerCase()) {
+            throw fail(
+                `live photo's image and video have the same extension, ${video.ext}`,
+            );
+        }
+        const path = withExtension(destination, image.ext);
+        const videoPath = withExtension(destination, video.ext);
+        for (const part of parts) {
+            await part.handle.sync();
+            await part.handle.close();
+        }
+        await rm(destination, { force: true });
+        await rename(image.tmpPath, path);
+        try {
+            await rename(video.tmpPath, videoPath);
+        } catch (err) {
+            await rm(path, { force: true }).catch(() => undefined);
+            throw err;
+        }
+        await fsyncPath(dir);
+        return { path, bytesWritten, videoPath };
+    } catch (err) {
+        // Best-effort cleanup, as in `stageAtomic`.
+        for (const part of parts) {
+            await part.handle.close().catch(() => undefined);
+            await rm(part.tmpPath, { force: true }).catch(() => undefined);
+        }
+        throw err;
+    }
+};
+
 // Fetch a stream and decrypt it to `destination`, retrying the whole sequence.
 //
 // The request is only the first third of a download. `getXStream` returns as
@@ -275,12 +507,45 @@ const fetchAndDecrypt = async (
     key: Uint8Array,
     destination: string,
     onProgress?: ProgressCallback,
-): Promise<number> =>
+    original?: EnteFile,
+): Promise<DownloadResult> =>
     withRetry(async () => {
         const stream = await openStream();
-        return decryptToTemp(destination, stream, header, key, onProgress);
+        try {
+            if (original?.metadata.fileType === "livePhoto") {
+                return await decryptLivePhoto(
+                    destination,
+                    stream,
+                    header,
+                    key,
+                    onProgress,
+                    original,
+                );
+            }
+            const bytesWritten = await decryptToTemp(
+                destination,
+                stream,
+                header,
+                key,
+                onProgress,
+                original,
+            );
+            return { path: destination, bytesWritten };
+        } catch (err) {
+            // Cancel the body so its connection is closed now rather than held
+            // until the stream is garbage collected. A backup run carries on
+            // past a failed file, so without this every failure would hold a
+            // socket. This covers every failure, including a temp file that
+            // cannot be opened and a header that is rejected before the body
+            // is read.
+            await stream.cancel(err).catch(() => undefined);
+            throw err;
+        }
     }, api.getRetryOptions());
 
+// Write `file`'s original to `outPath`. A live photo is written as its image
+// and its video beside `outPath` instead, and whatever was at `outPath` is
+// removed (see `decryptLivePhoto`).
 export const downloadFile = async (
     api: ApiClient,
     file: EnteFile,
@@ -292,15 +557,15 @@ export const downloadFile = async (
     const resolvedPath =
         outPath ?? sanitizeFileName(file.metadata.title, `file-${file.id}`);
     const header = fromBase64(file.file.decryptionHeader);
-    const bytesWritten = await fetchAndDecrypt(
+    return fetchAndDecrypt(
         api,
         () => api.getFileStream(file.id, { retry: false }),
         header,
         file.key,
         resolvedPath,
         onProgress,
+        file,
     );
-    return { path: resolvedPath, bytesWritten };
 };
 
 export const downloadThumbnail = async (
@@ -313,7 +578,7 @@ export const downloadThumbnail = async (
         outPath ??
         `thumb_${sanitizeFileName(file.metadata.title, `file-${file.id}`)}`;
     const header = fromBase64(file.thumbnail.decryptionHeader);
-    const bytesWritten = await fetchAndDecrypt(
+    return fetchAndDecrypt(
         api,
         () => api.getThumbnailStream(file.id, { retry: false }),
         header,
@@ -321,5 +586,4 @@ export const downloadThumbnail = async (
         resolvedPath,
         onProgress,
     );
-    return { path: resolvedPath, bytesWritten };
 };

src/filename.ts

@@ -35,3 +35,7 @@ export const safeExtension = (title: string): string => {
     const ext = extname(title);
     return /^\.[A-Za-z0-9]+$/.test(ext) ? ext : ".bin";
 };
+
+// `name` with its extension, if it has one, replaced by `ext` (".mov").
+export const withExtension = (name: string, ext: string): string =>
+    name.slice(0, name.length - extname(name).length) + ext;

src/index.ts

@@ -1,4 +1,8 @@
-export const VERSION = "0.0.0";
+// package.json is the one place the version is written. tsc copies it to
+// dist/package.json, so this path resolves from source and from dist/src/.
+import pkg from "../package.json" with { type: "json" };
+
+export const VERSION: string = pkg.version;
 
 export {
     Client,

src/library/content.ts

@@ -1,11 +1,13 @@
 // The on-disk content and thumbnail cache keyed by fileID (issue #46).
 //
 // Layout under `cacheDirectory`: `originals/<fileID>.<ext>` and
-// `thumbnails/<fileID>.<ext>`, flat directories at 0700 with files at 0600.
-// Content appears only by the streaming atomic writer's rename (the download
-// layer, #40), so a file that exists is whole — "present means complete". The
-// directory listing taken at `open()` is the record of what is cached, and the
-// orphan temp files a crashed write may have left are reaped there.
+// `thumbnails/<fileID>.<ext>`, flat directories at 0700 with files at 0600. A
+// live photo's original is two files, its image and its video, with
+// `originals/<fileID>.livephoto.json` naming them. Content appears only by the
+// streaming atomic writer's rename (the download layer, #40), so a file that
+// exists is whole — "present means complete". The directory listing taken at
+// `open()` is the record of what is cached, and the orphan temp files a crashed
+// write may have left are reaped there.
 //
 // A fetch goes through the shared request pools (#45): the content pool for
 // originals, the thumbnail pool for thumbnails. The pool limits concurrency,
@@ -15,14 +17,14 @@
 // Integrity. The reused streaming decrypt is the enforced guarantee: every
 // chunk is authenticated and the writer renames the file into place only once
 // the stream ends on TAG_FINAL, so a truncated or corrupt fetch throws and
-// nothing is stored. On top of that this module refuses to record a stored file
-// that came out empty. The design also asks for a content-hash comparison
-// against `FileMetadata.hash` (with a `fileSize` fallback); that is deferred —
-// see the PR — because the exact hash construction cannot be confirmed against
-// the repo's fixtures and `FileBlob.size` is the encrypted object size, not the
-// decrypted length this layer has.
+// nothing is stored. For an original whose metadata records a content hash
+// (`FileMetadata.hash`), the writer also hashes the decrypted bytes and stores
+// nothing if they differ, failing the fetch with an error naming the file. An
+// original with no recorded hash is stored unchecked, as the upstream client
+// does; thumbnails have none. On top of that this module refuses to record a
+// stored file that came out empty.
 
-import { existsSync, statSync } from "node:fs";
+import { existsSync, readFileSync, statSync } from "node:fs";
 import {
     chmod,
     mkdir,
@@ -32,13 +34,15 @@ import {
     statfs,
     utimes,
 } from "node:fs/promises";
-import { dirname, extname, join } from "node:path";
+import { basename, dirname, extname, join } from "node:path";
 
 import type { ApiClient } from "../api/client.js";
 import {
     downloadFile,
     downloadThumbnail,
     type ProgressCallback,
+    removeLeftoverTempFiles,
+    writeAtomic,
 } from "../download/index.js";
 import { safeExtension } from "../filename.js";
 import type { EnteFile } from "../model/types.js";
@@ -46,8 +50,6 @@ import type { Priority, RequestPools } from "./pools.js";
 
 const DIR_MODE = 0o700;
 const FILE_MODE = 0o600;
-const TEMP_PREFIX = ".quak-";
-const TEMP_SUFFIX = ".tmp";
 const GIB = 1024 * 1024 * 1024;
 // Owner ruling (#36): bound the originals cache at 100 GiB, but back off when
 // the volume has under 50 GiB free so the cache never crowds the disk.
@@ -78,6 +80,8 @@ const poolPriorityOf = (priority: ThumbnailPriority): Priority =>
 export interface ContentResult {
     path: string;
     bytes: number;
+    // A live photo's video. `path` and `bytes` are then its image's.
+    videoPath?: string;
 }
 
 // Progress for a single `original`/`thumbnail` call. A present file emits one
@@ -128,11 +132,14 @@ export interface ThumbnailsAPI {
 // stand-in so the cache logic runs with no crypto and no network. Pool routing,
 // dedup, present-checks and integrity live in the cache, not here.
 export interface ContentSource {
+    // Writes the original at `destination`. A live photo is written beside it
+    // as its image and its video instead, and their paths are returned, as
+    // `downloadFile` does.
     original(args: {
         file: EnteFile;
         destination: string;
         onProgress?: ProgressCallback;
-    }): Promise<{ bytesWritten: number }>;
+    }): Promise<{ bytesWritten: number; path?: string; videoPath?: string }>;
     thumbnail(args: {
         file: EnteFile;
         destination: string;
@@ -210,7 +217,9 @@ class AbortDrop extends Error {
     }
 }
 
-const originalName = (file: EnteFile): string =>
+// The originals/ name for a file: `<fileID><ext>`, the extension taken from the
+// title (or `.bin`). A backup names its originals the same way.
+export const originalName = (file: EnteFile): string =>
     `${file.id}${safeExtension(file.metadata.title)}`;
 
 // The fileID a cache filename encodes, or undefined when the name is not one
@@ -232,6 +241,73 @@ const fileSize = (path: string): number | undefined => {
     }
 };
 
+// Whether `path` is a regular file with content. A zero-byte file is the shape
+// an aborted write leaves, so it does not count.
+const hasContent = (path: string | undefined): boolean =>
+    path !== undefined && (fileSize(path) ?? 0) > 0;
+
+// A live photo's image and video are named with the extensions from inside its
+// ZIP, so their names alone do not say which is which. Wherever the cache or a
+// backup stores one, this JSON file beside them names both.
+const livePhotoFileName = (fileID: number): string =>
+    `${fileID}.livephoto.json`;
+
+// The image and video that the live photo's JSON file in `dir` names, or
+// undefined when there is none. Only names of the form the cache writes are
+// taken, so the file cannot point outside `dir`.
+const readLivePhoto = (
+    dir: string,
+    fileID: number,
+): { path: string; videoPath: string } | undefined => {
+    const valid = (name: unknown): name is string =>
+        typeof name === "string" && name === `${fileID}${safeExtension(name)}`;
+    try {
+        const { image, video } = JSON.parse(
+            readFileSync(join(dir, livePhotoFileName(fileID)), "utf-8"),
+        );
+        if (valid(image) && valid(video)) {
+            return { path: join(dir, image), videoPath: join(dir, video) };
+        }
+    } catch {
+        // No such file, or not one the cache wrote.
+    }
+    return undefined;
+};
+
+// Write the JSON file naming a live photo's image and video, both in `dir`.
+export const writeLivePhoto = (
+    dir: string,
+    fileID: number,
+    stored: { path: string; videoPath: string },
+): Promise<void> =>
+    writeAtomic(
+        join(dir, livePhotoFileName(fileID)),
+        new TextEncoder().encode(
+            JSON.stringify({
+                image: basename(stored.path),
+                video: basename(stored.videoPath),
+            }),
+        ),
+    );
+
+// The original of `file` as the cache or a backup stored it in `dir`, when all
+// of it is there: `<fileID><ext>`, or a live photo's image and video.
+export const storedOriginal = (
+    dir: string,
+    file: EnteFile,
+): { path: string; videoPath?: string } | undefined => {
+    if (file.metadata.fileType !== "livePhoto") {
+        const path = join(dir, originalName(file));
+        return hasContent(path) ? { path } : undefined;
+    }
+    const stored = readLivePhoto(dir, file.id);
+    return stored !== undefined &&
+        hasContent(stored.path) &&
+        hasContent(stored.videoPath)
+        ? stored
+        : undefined;
+};
+
 export class ContentCache implements PhotoContent, ThumbnailsAPI {
     private readonly pools: RequestPools;
     private readonly source: ContentSource;
@@ -239,10 +315,17 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
     private readonly getFile: (fileID: number) => EnteFile | undefined;
     private readonly originalsDir: string;
     private readonly thumbnailsDir: string;
-    // fileID -> absolute path of the cached bytes, seeded from the directory
-    // listing at open() and extended as fetches store new files.
-    private readonly originals = new Map<number, string>();
-    private readonly thumbnails = new Map<number, string>();
+    // fileID -> absolute path of the cached bytes, and for a live photo's
+    // original its video's, seeded from the directory listing at open() and
+    // extended as fetches store new files.
+    private readonly originals = new Map<
+        number,
+        { path: string; videoPath?: string }
+    >();
+    private readonly thumbnails = new Map<
+        number,
+        { path: string; videoPath?: string }
+    >();
     private readonly maxOriginalsBytes: number;
     private readonly freeBelowBytes: number;
     private readonly isPinned: (fileID: number) => boolean;
@@ -302,9 +385,9 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
     pathsFor(fileID: number): CachedPaths {
         const out: CachedPaths = {};
         const original = this.originals.get(fileID);
-        if (original !== undefined) out.originalPath = original;
+        if (original !== undefined) out.originalPath = original.path;
         const thumbnail = this.thumbnails.get(fileID);
-        if (thumbnail !== undefined) out.thumbnailPath = thumbnail;
+        if (thumbnail !== undefined) out.thumbnailPath = thumbnail.path;
         return out;
     }
 
@@ -322,6 +405,27 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         return this.get(fileID, "thumbnail", "on-demand", opts?.onProgress);
     }
 
+    // Get an original for a backup. One not present anywhere is written
+    // straight to `destination` and recorded there, so no second copy lands
+    // in the cache; one already present is returned where it is.
+    async backupOriginal(
+        fileID: number,
+        destination: string,
+    ): Promise<ContentResult> {
+        const result = await this.acquire(
+            fileID,
+            "original",
+            "on-demand",
+            undefined,
+            { destination },
+        );
+        return {
+            path: result.path,
+            bytes: result.bytes,
+            videoPath: result.videoPath,
+        };
+    }
+
     async ensure(args: EnsureOptions): Promise<EnsureResult[]> {
         return this.ensureThumbnails(args);
     }
@@ -418,51 +522,72 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
                 ? { status: "skipped", bytes: result.bytes }
                 : { status: "done", bytes: result.bytes },
         );
-        return { path: result.path, bytes: result.bytes };
+        return {
+            path: result.path,
+            bytes: result.bytes,
+            videoPath: result.videoPath,
+        };
     }
 
     // The core: return the cached path if present, else fetch through the pool,
     // store, and return it. `cached` distinguishes a present hit (no network,
-    // no download event) from a fresh fetch.
+    // no download event) from a fresh fetch. A fetched original is stored at
+    // `opts.destination` when given, instead of in `originalsDir`. A live
+    // photo's original is present only with its video, and is returned with
+    // it.
     private async acquire(
         fileID: number,
         kind: Kind,
         priority: Priority,
         signal: AbortSignal | undefined,
-        opts?: { onByte?: ProgressCallback },
-    ): Promise<{ path: string; bytes: number; cached: boolean }> {
+        opts?: { onByte?: ProgressCallback; destination?: string },
+    ): Promise<{
+        path: string;
+        bytes: number;
+        videoPath?: string;
+        cached: boolean;
+    }> {
         const file = this.getFile(fileID);
         if (!file) throw new Error(`content cache: unknown file ${fileID}`);
+        const isLivePhoto =
+            kind === "original" && file.metadata.fileType === "livePhoto";
 
         const known = kind === "original" ? this.originals : this.thumbnails;
         const cached = known.get(fileID);
         if (cached !== undefined) {
-            const size = fileSize(cached);
-            if (size !== undefined && size > 0) {
+            const size = fileSize(cached.path);
+            if (
+                size !== undefined &&
+                size > 0 &&
+                (!isLivePhoto || hasContent(cached.videoPath))
+            ) {
                 // Returning an original's path is a use: bump its mtime so LRU
                 // order reflects it and survives a restart with no ledger.
                 if (
                     kind === "original" &&
-                    dirname(cached) === this.originalsDir
+                    dirname(cached.path) === this.originalsDir
                 )
-                    await this.touch(cached);
-                return { path: cached, bytes: size, cached: true };
+                    await this.touch(cached.path);
+                return { ...cached, bytes: size, cached: true };
             }
-            // A recorded file that has since gone re-fetches below.
+            // A recorded file that has since gone, or a live photo an earlier
+            // version stored as one ZIP, re-fetches below.
             known.delete(fileID);
         }
 
         // An original a backup already stored counts as present.
         if (kind === "original" && this.downloadDirectory !== undefined) {
-            const backupPath = join(
-                this.downloadDirectory,
-                "originals",
-                originalName(file),
+            const stored = storedOriginal(
+                join(this.downloadDirectory, "originals"),
+                file,
             );
-            const size = fileSize(backupPath);
-            if (size !== undefined && size > 0) {
-                this.originals.set(fileID, backupPath);
-                return { path: backupPath, bytes: size, cached: true };
+            if (stored !== undefined) {
+                this.originals.set(fileID, stored);
+                return {
+                    ...stored,
+                    bytes: fileSize(stored.path) ?? 0,
+                    cached: true,
+                };
             }
         }
 
@@ -470,7 +595,7 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
             kind === "original" ? this.originalsDir : this.thumbnailsDir;
         const dest =
             kind === "original"
-                ? join(dir, originalName(file))
+                ? (opts?.destination ?? join(dir, originalName(file)))
                 : join(dir, `${fileID}${THUMBNAIL_EXT}`);
         const pool =
             kind === "original" ? this.pools.content : this.pools.thumbnails;
@@ -491,21 +616,39 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
                         ? this.beginOriginalWrite(fileID)
                         : null;
                 try {
-                    await this.download(file, dest, kind, opts?.onByte);
-                    await chmod(dest, FILE_MODE);
-                    const size = (await stat(dest)).size;
-                    if (size === 0) {
-                        throw new Error(
-                            `content cache: ${kind} ${fileID} stored empty`,
-                        );
+                    const stored = await this.download(
+                        file,
+                        dest,
+                        kind,
+                        opts?.onByte,
+                    );
+                    for (const path of [stored.path, stored.videoPath]) {
+                        if (path === undefined) continue;
+                        await chmod(path, FILE_MODE);
+                        if ((await stat(path)).size === 0) {
+                            throw new Error(
+                                `content cache: ${kind} ${fileID} stored empty`,
+                            );
+                        }
                     }
-                    known.set(fileID, dest);
+                    // A backup records its own live photos.
+                    if (
+                        stored.videoPath !== undefined &&
+                        opts?.destination === undefined
+                    ) {
+                        await writeLivePhoto(dir, fileID, {
+                            path: stored.path,
+                            videoPath: stored.videoPath,
+                        });
+                    }
+                    known.set(fileID, stored);
                     // A fresh original may have crossed the limit; make room by
                     // evicting least-recently-used originals. An over-budget
                     // fetch keeps the file it returns, and no overlapping
                     // sibling is evicted. Thumbnails are never bounded.
                     if (write) await this.enforceOriginalsLimit(write);
-                    return { path: dest, bytes: size, cached: false };
+                    const size = (await stat(stored.path)).size;
+                    return { ...stored, bytes: size, cached: false };
                 } finally {
                     if (write) this.inFlightOriginals.delete(write);
                 }
@@ -514,18 +657,24 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         );
     }
 
+    // Fetch into `destination`, returning where the bytes landed: there, or
+    // for a live photo, its image and video beside it.
     private async download(
         file: EnteFile,
         destination: string,
         kind: Kind,
         onProgress: ProgressCallback | undefined,
-    ): Promise<number> {
+    ): Promise<{ path: string; videoPath?: string }> {
         const args = { file, destination, onProgress };
-        const result =
-            kind === "original"
-                ? await this.source.original(args)
-                : await this.source.thumbnail(args);
-        return result.bytesWritten;
+        if (kind === "thumbnail") {
+            await this.source.thumbnail(args);
+            return { path: destination };
+        }
+        const result = await this.source.original(args);
+        return {
+            path: result.path ?? destination,
+            videoPath: result.videoPath,
+        };
     }
 
     // Best-effort bump of a file's mtime to now; a failed touch must never fail
@@ -536,13 +685,14 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
     }
 
     // Every stored original that lives under `originalsDir` (a backup-directory
-    // hit recorded in the map is excluded), with its size and mtime. Entries
-    // whose file has vanished are dropped from the map. Backups and thumbnails
-    // are never counted.
+    // hit recorded in the map is excluded), with its size and mtime; a live
+    // photo's size includes its video. Entries whose file has vanished are
+    // dropped from the map. Backups and thumbnails are never counted.
     private async measureOriginals(): Promise<{
         entries: {
             fileID: number;
             path: string;
+            videoPath?: string;
             size: number;
             mtimeMs: number;
         }[];
@@ -551,21 +701,28 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         const entries: {
             fileID: number;
             path: string;
+            videoPath?: string;
             size: number;
             mtimeMs: number;
         }[] = [];
         let used = 0;
-        for (const [fileID, path] of this.originals) {
+        for (const [fileID, { path, videoPath }] of this.originals) {
             if (dirname(path) !== this.originalsDir) continue;
             try {
                 const s = await stat(path);
+                const size =
+                    s.size +
+                    (videoPath === undefined
+                        ? 0
+                        : (await stat(videoPath)).size);
                 entries.push({
                     fileID,
                     path,
-                    size: s.size,
+                    videoPath,
+                    size,
                     mtimeMs: s.mtimeMs,
                 });
-                used += s.size;
+                used += size;
             } catch {
                 this.originals.delete(fileID);
             }
@@ -629,6 +786,18 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
                 for (const e of evictable) {
                     if (remaining <= limit) break;
                     await rm(e.path, { force: true });
+                    // A live photo goes whole: its video and the JSON file
+                    // naming the two go with its image.
+                    if (e.videoPath !== undefined) {
+                        await rm(e.videoPath, { force: true });
+                        await rm(
+                            join(
+                                this.originalsDir,
+                                livePhotoFileName(e.fileID),
+                            ),
+                            { force: true },
+                        );
+                    }
                     this.originals.delete(e.fileID);
                     remaining -= e.size;
                 }
@@ -653,23 +822,30 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         await chmod(dir, DIR_MODE);
     }
 
-    private async scan(dir: string, into: Map<number, string>): Promise<void> {
+    private async scan(
+        dir: string,
+        into: Map<number, { path: string; videoPath?: string }>,
+    ): Promise<void> {
+        // Another process sharing this cache may still be writing its temp
+        // files, so only those whose process has exited are removed.
+        removeLeftoverTempFiles(dir);
         let entries: string[];
         try {
             entries = await readdir(dir);
         } catch {
             return;
         }
+        const names = new Set(entries);
         for (const name of entries) {
-            if (name.startsWith(TEMP_PREFIX) && name.endsWith(TEMP_SUFFIX)) {
-                await rm(join(dir, name), { force: true }).catch(
-                    () => undefined,
-                );
-                continue;
-            }
             const id = fileIDFromName(name);
             const path = join(dir, name);
-            if (id !== undefined && existsSync(path)) into.set(id, path);
+            if (id === undefined || !existsSync(path)) continue;
+            // A live photo's image and video are one entry, as the JSON file
+            // beside them names them.
+            const livePhoto = names.has(livePhotoFileName(id))
+                ? readLivePhoto(dir, id)
+                : undefined;
+            into.set(id, livePhoto ?? { path });
         }
     }
 }

src/library/index.ts

@@ -26,6 +26,7 @@
 // store marked unsaved until a later save actually lands, so a stuck disk is
 // never masked by a subsequent empty refresh.
 
+import { rm } from "node:fs/promises";
 import { join } from "node:path";
 import envPaths from "env-paths";
 
@@ -97,6 +98,11 @@ export {
 
 export const DEFAULT_REFRESH_INTERVAL_SECONDS = 3;
 
+// The account's cache directory when `cacheDirectory` is not given: the
+// env-paths cache directory plus the user id, so each account has its own.
+export const defaultCacheDirectory = (userID: number): string =>
+    join(envPaths("quak", { suffix: "" }).cache, String(userID));
+
 // Project a metadata store into by-id records, filling each record's cache
 // paths from the content cache when one is given. Shared by the live read
 // projection and the precache's initial seeding at open().
@@ -266,8 +272,9 @@ export class Library {
     // that, a fresh read propagates it.
     private cycle?: Promise<void>;
     // Guards the ML fetch pass so a slow backfill never runs twice at once; a
-    // refresh whose pass is still running kicks nothing new.
-    private mlFetching = false;
+    // refresh whose pass is still running kicks nothing new. Holds the running
+    // pass, so `close()` can wait for it.
+    private mlFetch?: Promise<void>;
     private closed = false;
     private lastRefreshAt?: number;
     private lastError?: string;
@@ -342,11 +349,21 @@ export class Library {
     static async open(opts: LibraryOptions): Promise<Library> {
         const { userID } = opts.client.whoami();
         const cacheDirectory =
-            opts.cacheDirectory ??
-            join(envPaths("quak", { suffix: "" }).cache, String(userID));
-        const store = await MetadataStore.load(
-            join(cacheDirectory, "metadata.json"),
-        );
+            opts.cacheDirectory ?? defaultCacheDirectory(userID);
+        const metadataPath = join(cacheDirectory, "metadata.json");
+        let store = await MetadataStore.load(metadataPath);
+        // A cache directory given explicitly can hold another account's cache.
+        // Its records and cursor are not this account's, so delete it and the
+        // ML data beside it and start empty. A user ID of 0 means the cache
+        // was never refreshed and so holds nothing to discard.
+        if (store.userID !== 0 && store.userID !== userID) {
+            await rm(metadataPath, { force: true });
+            await rm(join(cacheDirectory, "mldata"), {
+                recursive: true,
+                force: true,
+            });
+            store = await MetadataStore.load(metadataPath);
+        }
         const intervalMs =
             (opts.refreshIntervalSeconds ?? DEFAULT_REFRESH_INTERVAL_SECONDS) *
             1000;
@@ -521,11 +538,13 @@ export class Library {
     }
 
     // Back up every in-scope file to `downloadDirectory` in the historical
-    // on-disk layout, with a durable failure ledger (issue #51). Refreshes
-    // first, fetches pending originals (and optional thumbnails) through the
-    // content cache and pools, then rebuilds the derived symlink/JSON views
-    // from the model. Throws before any network work when no download directory
-    // is available or no content cache backs the originals it must fetch.
+    // on-disk layout, with a durable failure ledger (issue #51). Waits for a
+    // completed refresh first, as `fresh()` does, joining one already running,
+    // and rejects before touching any file when it fails. Then fetches pending
+    // originals (and optional thumbnails) through the content cache and pools,
+    // and rebuilds the derived symlink/JSON views from the model. Throws before
+    // any network work when no download directory is available or no content
+    // cache backs the originals it must fetch.
     backup(opts?: BackupOptions): Promise<BackupResult> {
         const downloadDirectory =
             opts?.downloadDirectory ?? this.downloadDirectory;
@@ -549,10 +568,11 @@ export class Library {
         const cache = this.cache;
         return runBackup(
             {
-                refresh: () => this.runRefresh(),
+                refresh: () => this.refreshNow(),
                 listCollections: () => this.store.listCollections(),
                 listFiles: (id) => this.store.listFiles(id),
-                original: (fileID) => cache!.original(fileID),
+                original: (fileID, destination) =>
+                    cache!.backupOriginal(fileID, destination),
                 thumbnail: (fileID) => cache!.thumbnail(fileID),
             },
             { ...opts, downloadDirectory },
@@ -560,14 +580,21 @@ export class Library {
     }
 
     // Stop the background timer. Idempotent. An in-flight refresh is left to
-    // finish; it will not schedule another cycle once closed.
-    close(): void {
+    // finish; it will not schedule another cycle once closed. The returned
+    // promise resolves once that refresh (including its cache write), the ML
+    // fetch pass and the precache fetches already running have all finished,
+    // so a caller can then remove the cache directory. A refresh failure is
+    // reported through `status()`, not thrown here.
+    async close(): Promise<void> {
         this.closed = true;
-        this.precache?.close();
+        const precacheClosed = this.precache?.close();
         if (this.timer !== undefined) {
             clearTimeout(this.timer);
             this.timer = undefined;
         }
+        await this.cycle?.catch(() => {});
+        await this.mlFetch;
+        await precacheClosed;
     }
 
     private scheduleNext(): void {
@@ -631,7 +658,9 @@ export class Library {
             // outside the refresh's success/failure so a fetch or disk problem
             // there never marks the metadata refresh failed, and it is not
             // awaited so it never stalls the refresh interval.
-            void this.runMLFetch();
+            this.mlFetch ??= this.runMLFetch().finally(() => {
+                this.mlFetch = undefined;
+            });
         } catch (err) {
             const error = err instanceof Error ? err.message : String(err);
             this.lastError = error;
@@ -745,13 +774,12 @@ export class Library {
         // Bind so the call keeps the client as its receiver when invoked
         // through the pool below.
         const fetchMLData = this.client.fetchMLData?.bind(this.client);
-        if (!mldata || !fetchMLData || this.closed || this.mlFetching) return;
+        if (!mldata || !fetchMLData || this.closed) return;
 
         const files = this.uniqueFiles();
         const needed = mldata.neededFor(files);
         if (needed.length === 0) return;
 
-        this.mlFetching = true;
         this.emit({ operation: "fetchMLData", status: "started" });
         try {
             const fileKeys = new Map<number, Uint8Array>();
@@ -784,8 +812,6 @@ export class Library {
             const error = err instanceof Error ? err.message : String(err);
             this.lastMLError = error;
             this.emit({ operation: "fetchMLData", status: "failed", error });
-        } finally {
-            this.mlFetching = false;
         }
     }
 

src/library/precache.ts

@@ -92,9 +92,10 @@ export class Precache {
     private pinned = new Set<number>();
 
     // A sweep runs at most once per fill at a time; a re-kick while one runs is
-    // a no-op, and the next refresh re-kicks after it finishes.
-    private thumbRunning = false;
-    private originalsRunning = false;
+    // a no-op, and the next refresh re-kicks after it finishes. Each holds the
+    // running sweep, so `close()` can wait for it.
+    private thumbSweep?: Promise<void>;
+    private originalsSweep?: Promise<void>;
     private readonly aborter = new AbortController();
     private closed = false;
 
@@ -191,15 +192,19 @@ export class Precache {
     }
 
     // Stop the fills. In-flight fetches are left to settle; queued ones drop.
-    close(): void {
+    // Resolves once both sweeps have finished, so nothing is still writing.
+    async close(): Promise<void> {
         this.closed = true;
         this.aborter.abort();
+        await Promise.all([
+            this.thumbSweep?.catch(() => {}),
+            this.originalsSweep?.catch(() => {}),
+        ]);
     }
 
     private kickThumbnails(): void {
-        if (this.thumbRunning) return;
-        this.thumbRunning = true;
-        void this.sweep(
+        if (this.thumbSweep) return;
+        this.thumbSweep = this.sweep(
             "precacheThumbnails",
             () => this.thumbOrder,
             (id) => this.cache!.pathsFor(id).thumbnailPath !== undefined,
@@ -211,14 +216,13 @@ export class Precache {
                     signal: this.aborter.signal,
                 }),
         ).finally(() => {
-            this.thumbRunning = false;
+            this.thumbSweep = undefined;
         });
     }
 
     private kickOriginals(): void {
-        if (this.originalsRunning) return;
-        this.originalsRunning = true;
-        void this.sweep(
+        if (this.originalsSweep) return;
+        this.originalsSweep = this.sweep(
             "precacheOriginals",
             () => this.originalsOrder,
             (id) => this.cache!.pathsFor(id).originalPath !== undefined,
@@ -229,7 +233,7 @@ export class Precache {
                     signal: this.aborter.signal,
                 }),
         ).finally(() => {
-            this.originalsRunning = false;
+            this.originalsSweep = undefined;
         });
     }
 

src/library/read.ts

@@ -80,7 +80,8 @@ export class Photo {
     }
 
     // Fetch and cache the full-resolution original, returning its on-disk path
-    // and byte length. Served from the cache (or the backup download directory)
+    // and byte length; for a live photo, its image's, and its video's path as
+    // `videoPath`. Served from the cache (or the backup download directory)
     // when already present, otherwise fetched through the content pool.
     async original(opts?: ContentOptions): Promise<ContentResult> {
         return this.contentOrThrow().original(this.rec.fileID, opts);

src/library/records.ts

@@ -42,6 +42,7 @@ export interface PhotoRecord {
     isArchived: boolean;
     isHidden: boolean;
     // Local cache paths, set once a later phase caches the bytes; unset here.
+    // A live photo's `originalPath` is its image.
     thumbnailPath?: string;
     originalPath?: string;
 }

src/metadata-backup.ts

@@ -5,7 +5,11 @@ import exifReader from "exif-reader";
 import type { Client } from "./client.js";
 import type { Library, Photo } from "./library/index.js";
 import { sanitizeFileName } from "./filename.js";
-import { fetchMLData } from "./mldata-fetch.js";
+import {
+    fetchMLDataBatch,
+    MLDATA_BATCH_SIZE,
+    type MLData,
+} from "./mldata-fetch.js";
 import type { EnteFile } from "./model/types.js";
 
 export type ProgressCallback = (message: string) => void;
@@ -15,114 +19,137 @@ export interface MetadataBackupOptions {
     onProgress?: ProgressCallback;
 }
 
-// Extract the raw EXIF APP1 segment from JPEG bytes. Returns the EXIF
-// data buffer (starting after the APP1 length field, at the "Exif\0\0"
-// header) or undefined if no APP1 marker is found.
-const extractExifFromJpeg = (buf: Uint8Array): Buffer | undefined => {
-    if (buf[0] !== 0xff || buf[1] !== 0xd8) return undefined;
+// Find the raw EXIF APP1 segment in JPEG bytes. Returns `exif` (the segment
+// data, starting at the "Exif\0\0" header) when there is one, nothing when the
+// bytes are not a JPEG or carry no EXIF, and `error` when the segment layout is
+// malformed. Each segment length is checked against the bytes that remain and
+// each step moves forward by at least 4 bytes, so the scan ends on any input.
+export const extractExifFromJpeg = (
+    buf: Uint8Array,
+): { exif?: Buffer; error?: string } => {
+    if (buf[0] !== 0xff || buf[1] !== 0xd8) return {};
     let offset = 2;
-    while (offset < buf.length - 1) {
-        if (buf[offset] !== 0xff) return undefined;
+    while (offset < buf.length) {
+        if (offset + 2 > buf.length)
+            return { error: `truncated segment marker at byte ${offset}` };
+        if (buf[offset] !== 0xff)
+            return { error: `no segment marker at byte ${offset}` };
         const marker = buf[offset + 1]!;
-        if (marker === 0xda) break; // start of scan, no more markers
-        if (offset + 3 >= buf.length) break;
+        if (marker === 0xda) return {}; // start of scan, no more markers
+        if (offset + 4 > buf.length)
+            return { error: `truncated segment length at byte ${offset}` };
         const len = (buf[offset + 2]! << 8) | buf[offset + 3]!;
+        // The length counts its own two bytes, so anything under 2 is invalid.
+        if (len < 2)
+            return {
+                error: `segment length ${len} at byte ${offset} is too small`,
+            };
+        if (offset + 2 + len > buf.length)
+            return {
+                error: `segment length ${len} at byte ${offset} runs past the end of the file`,
+            };
         if (marker === 0xe1) {
-            // APP1 — check for "Exif\0\0" header
+            // APP1 — check for "Exif\0\0" header. A length under 8 cannot hold
+            // the six-byte header, so the segment is not EXIF; below 6 the
+            // bytes compared would also lie past the segment.
             if (
+                len >= 8 &&
                 buf[offset + 4] === 0x45 &&
                 buf[offset + 5] === 0x78 &&
                 buf[offset + 6] === 0x69 &&
                 buf[offset + 7] === 0x66
             ) {
-                return Buffer.from(
-                    buf.buffer,
-                    buf.byteOffset + offset + 4,
-                    len - 2,
-                );
+                return {
+                    exif: Buffer.from(
+                        buf.buffer,
+                        buf.byteOffset + offset + 4,
+                        len - 2,
+                    ),
+                };
             }
         }
         offset += 2 + len;
     }
-    return undefined;
+    return { error: "file ends before the image data" };
 };
 
-const extractImageMetadata = (
+// Extract dimensions, EXIF and XMP from a file's bytes. When the EXIF segment
+// is malformed or cannot be parsed, the record carries the reason in
+// `exifError`.
+export const extractImageMetadata = (
     fileBytes: Uint8Array,
 ): Record<string, unknown> | undefined => {
+    const result: Record<string, unknown> = {};
+
+    // Try to get dimensions from JPEG decode
     try {
-        const result: Record<string, unknown> = {};
-
-        // Try to get dimensions from JPEG decode
-        try {
-            const decoded = jpeg.decode(fileBytes, {
-                useTArray: true,
-                formatAsRGBA: false,
-            });
-            result.format = "jpeg";
-            result.width = decoded.width;
-            result.height = decoded.height;
-        } catch {
-            // Not a JPEG or corrupt; still try EXIF extraction
-        }
-
-        const exifBuf = extractExifFromJpeg(fileBytes);
-        if (exifBuf) {
-            try {
-                result.exif = exifReader(exifBuf);
-            } catch {
-                result.exifRaw = exifBuf.toString("base64");
-            }
-        }
-
-        // Extract XMP (look for "http://ns.adobe.com/xap" in the bytes)
-        const xmpStart = Buffer.from(fileBytes).indexOf("<?xpacket begin");
-        if (xmpStart !== -1) {
-            const xmpEnd = Buffer.from(fileBytes).indexOf(
-                "<?xpacket end",
-                xmpStart,
-            );
-            if (xmpEnd !== -1) {
-                const end = Buffer.from(fileBytes).indexOf("?>", xmpEnd);
-                result.xmp = Buffer.from(fileBytes)
-                    .subarray(xmpStart, end !== -1 ? end + 2 : xmpEnd + 50)
-                    .toString("utf-8");
-            }
-        }
-
-        return Object.keys(result).length > 0 ? result : undefined;
+        const decoded = jpeg.decode(fileBytes, {
+            useTArray: true,
+            formatAsRGBA: false,
+        });
+        result.format = "jpeg";
+        result.width = decoded.width;
+        result.height = decoded.height;
     } catch {
-        return undefined;
+        // Not every original is a JPEG (PNG, HEIC, video), so a failed decode
+        // is expected and only means no dimensions; a malformed JPEG is still
+        // reported below through `exifError`.
     }
+
+    const { exif, error } = extractExifFromJpeg(fileBytes);
+    if (error) result.exifError = error;
+    if (exif) {
+        try {
+            result.exif = exifReader(exif);
+        } catch (err) {
+            result.exifRaw = exif.toString("base64");
+            result.exifError = err instanceof Error ? err.message : String(err);
+        }
+    }
+
+    // Extract XMP (look for "http://ns.adobe.com/xap" in the bytes)
+    const xmpStart = Buffer.from(fileBytes).indexOf("<?xpacket begin");
+    if (xmpStart !== -1) {
+        const xmpEnd = Buffer.from(fileBytes).indexOf(
+            "<?xpacket end",
+            xmpStart,
+        );
+        if (xmpEnd !== -1) {
+            const end = Buffer.from(fileBytes).indexOf("?>", xmpEnd);
+            result.xmp = Buffer.from(fileBytes)
+                .subarray(xmpStart, end !== -1 ? end + 2 : xmpEnd + 50)
+                .toString("utf-8");
+        }
+    }
+
+    return Object.keys(result).length > 0 ? result : undefined;
 };
 
 // Read a file's original bytes through the library's content cache and extract
 // its embedded image metadata. The bytes come from `photo.original()` — the
 // same on-disk cache the rest of the library fills — rather than a fresh
-// per-call download to a throwaway temp file.
+// per-call download to a throwaway temp file. For a live photo, its `path` is
+// the image.
 const extractExif = async (
     photo: Photo,
 ): Promise<Record<string, unknown> | undefined> => {
-    try {
-        const { path } = await photo.original();
-        const fileBytes = new Uint8Array(readFileSync(path));
-        return extractImageMetadata(fileBytes);
-    } catch {
-        return undefined;
-    }
+    const { path } = await photo.original();
+    const fileBytes = new Uint8Array(readFileSync(path));
+    return extractImageMetadata(fileBytes);
 };
 
 // Dump every decrypted metadata layer the account holds into a directory tree
 // of plain JSON: account, per-collection, and per-file records including the
 // private and public magic metadata and (by default) the ML data. Collections
-// and files are enumerated from the library's cache rather than a fresh server
-// scan; the ML fetch and EXIF extraction are unchanged.
+// and files are enumerated from the library's cache, which the caller refreshes
+// first. Returns how many ML data requests failed; their files are still
+// written, with `mlDataError` in place of `mlData`.
 export const runMetadataBackup = async (
     lib: Library,
     client: Client,
     outDir: string,
     opts?: MetadataBackupOptions,
-): Promise<void> => {
+): Promise<{ failedMLBatches: number }> => {
     const log = opts?.onProgress ?? (() => {});
     const wantExif = opts?.exif ?? false;
 
@@ -187,12 +214,31 @@ export const runMetadataBackup = async (
         }
     }
 
+    // One failed request (retries exhausted) must not end the dump: its files
+    // get the reason in `mlDataError` and the other batches go on.
     log("Fetching ML data (face detections, CLIP embeddings)...");
-    const mlDataMap = await fetchMLData(
-        client.getApiClient(),
-        [...fileKeys.keys()],
-        fileKeys,
-    );
+    const mlDataMap = new Map<number, MLData>();
+    const mlDataErrors = new Map<number, string>();
+    let failedMLBatches = 0;
+    const fileIDs = [...fileKeys.keys()];
+    for (let i = 0; i < fileIDs.length; i += MLDATA_BATCH_SIZE) {
+        const batch = fileIDs.slice(i, i + MLDATA_BATCH_SIZE);
+        try {
+            const result = await fetchMLDataBatch(
+                client.getApiClient(),
+                batch,
+                fileKeys,
+            );
+            for (const [id, payload] of result) mlDataMap.set(id, payload);
+        } catch (err) {
+            const reason = err instanceof Error ? err.message : String(err);
+            failedMLBatches++;
+            log(
+                `ML data request for ${batch.length} file(s) failed: ${reason}`,
+            );
+            for (const id of batch) mlDataErrors.set(id, reason);
+        }
+    }
     log(`Got ML data for ${mlDataMap.size} file(s)`);
 
     const writtenFileIDs = new Set<number>();
@@ -212,11 +258,18 @@ export const runMetadataBackup = async (
 
         const ml = mlDataMap.get(file.id);
         if (ml) fileMeta.mlData = ml;
+        const mlError = mlDataErrors.get(file.id);
+        if (mlError) fileMeta.mlDataError = mlError;
 
         if (wantExif && !writtenFileIDs.has(file.id)) {
             log(`[${file.metadata.title}] Extracting EXIF...`);
-            const exifData = await extractExif(photo);
-            if (exifData) fileMeta.imageMetadata = exifData;
+            try {
+                const exifData = await extractExif(photo);
+                if (exifData) fileMeta.imageMetadata = exifData;
+            } catch (err) {
+                fileMeta.imageMetadataError =
+                    err instanceof Error ? err.message : String(err);
+            }
         }
         writtenFileIDs.add(file.id);
 
@@ -227,4 +280,5 @@ export const runMetadataBackup = async (
     }
 
     log("Metadata backup complete.");
+    return { failedMLBatches };
 };

src/mldata-fetch.ts

@@ -5,9 +5,8 @@
 // comes back encrypted under the file's own key and gzipped; decrypting and
 // gunzipping yields the JSON payload
 // `{ face: { faces: [...] }, clip: { embedding } }`. Ente caps a request at 200
-// ids, so `fetchMLData` batches for callers that want many at once while
-// `fetchMLDataBatch` is the single-request unit the library submits to its
-// request pool.
+// ids, so callers that want many at once split them into batches of
+// `MLDATA_BATCH_SIZE` and call `fetchMLDataBatch` once per batch.
 
 import { gunzipSync } from "node:zlib";
 
@@ -69,25 +68,3 @@ export const fetchMLDataBatch = async (
     }
     return result;
 };
-
-// Fetch ML data for arbitrarily many ids, batching at `MLDATA_BATCH_SIZE`. Used
-// by the one-shot metadata backup; the library fetches through its request pool
-// with `fetchMLDataBatch` instead.
-export const fetchMLData = async (
-    api: ApiClient,
-    fileIDs: number[],
-    fileKeys: Map<number, Uint8Array>,
-): Promise<Map<number, MLData>> => {
-    const result = new Map<number, MLData>();
-    for (let i = 0; i < fileIDs.length; i += MLDATA_BATCH_SIZE) {
-        const batch = fileIDs.slice(i, i + MLDATA_BATCH_SIZE);
-        for (const [id, payload] of await fetchMLDataBatch(
-            api,
-            batch,
-            fileKeys,
-        )) {
-            result.set(id, payload);
-        }
-    }
-    return result;
-};

src/model/decrypt.ts

@@ -34,6 +34,28 @@ const FILE_TYPE_MAP: Record<number, FileType> = {
 
 const parseFileType = (n: number): FileType => FILE_TYPE_MAP[n] ?? "unknown";
 
+// The hash the uploading client recorded for the original's bytes, read the
+// way the upstream client's `metadataHash` reads it: `hash` if present,
+// otherwise, for a live photo from an older client that wrote the two parts
+// separately, `<imageHash>:<videoHash>`. A field that is not a non-empty
+// string counts as absent, and a file with no hash at all is normal.
+const expectedHash = (json: Record<string, unknown>): string | undefined => {
+    const text = (v: unknown): string | undefined =>
+        typeof v === "string" && v !== "" ? v : undefined;
+    const hash = text(json.hash);
+    if (hash !== undefined) return hash;
+    const imageHash = text(json.imageHash);
+    const videoHash = text(json.videoHash);
+    if (
+        json.fileType === 2 &&
+        imageHash !== undefined &&
+        videoHash !== undefined
+    ) {
+        return `${imageHash}:${videoHash}`;
+    }
+    return undefined;
+};
+
 export const decryptCollection = (
     raw: RawCollection,
     keys: KeyMaterial,
@@ -115,7 +137,7 @@ export const decryptFile = (
         modificationTime: metadataJSON.modificationTime ?? 0,
         latitude: metadataJSON.latitude,
         longitude: metadataJSON.longitude,
-        hash: metadataJSON.hash,
+        hash: expectedHash(metadataJSON),
     };
 
     const magicMetadata = decryptMagicMetadata(raw.magicMetadata, key);

src/model/types.ts

@@ -29,6 +29,9 @@ export interface FileMetadata {
     modificationTime: Microseconds;
     latitude?: number;
     longitude?: number;
+    // The content hash the uploader recorded (see `expectedHash` in
+    // decrypt.ts); `downloadFile` refuses an original that does not match it.
+    // Absent for files from very old clients.
     hash?: string;
 }
 

src/retry.ts

@@ -88,18 +88,21 @@ const MAX_CAUSE_DEPTH = 8;
 // errno on the error it throws — it hangs the underlying socket error off
 // `cause`, sometimes more than one level down — so a classifier that only read
 // the top-level error would see a bare `Error` and call every dropped
-// connection permanent.
-const causeCodes = (err: unknown): string[] => {
+// connection permanent. `complete` is false when the walk stopped at the
+// depth limit with more of the chain still below it.
+const causeCodes = (err: unknown): { codes: string[]; complete: boolean } => {
     const codes: string[] = [];
     let current: unknown = err;
     for (let depth = 0; depth < MAX_CAUSE_DEPTH; depth++) {
-        if (current === null || typeof current !== "object") break;
+        if (current === null || typeof current !== "object") {
+            return { codes, complete: true };
+        }
         const { code, cause } = current as { code?: unknown; cause?: unknown };
         if (typeof code === "string") codes.push(code);
-        if (cause === current) break;
+        if (cause === current) return { codes, complete: true };
         current = cause;
     }
-    return codes;
+    return { codes, complete: current === null || typeof current !== "object" };
 };
 
 const isAbort = (err: unknown): boolean => {
@@ -145,15 +148,15 @@ export const isRetryable = (err: unknown): boolean => {
     // have succeeded; the cost of the imprecision is bounded by the attempt
     // count.
     if (err instanceof TypeError) return true;
-    return causeCodes(err).some((code) => TRANSPORT_CODES.has(code));
+    return causeCodes(err).codes.some((code) => TRANSPORT_CODES.has(code));
 };
 
 // Could the first attempt already have taken effect on the server?
 //
 // `isRetryable` is the wrong question for a request that changes state.
-// quak's non-idempotent calls are `/users/srp/create-session`,
-// `/users/two-factor/verify` — which consumes one of a small number of 2FA
-// attempts — and `/files/thumbnail`. They are replayed only on the failures in
+// `postJSON` and `putJSON` use this for every `POST` and `PUT` listed in the
+// README under "Endpoints used"; verifying a second factor, for one, consumes
+// one of a small number of attempts. They are replayed only on the failures in
 // `CONNECT_CODES`, which establish that no TCP connection to the server ever
 // existed: there was no address to connect to, or the peer refused the
 // connection outright. A request byte cannot have been transmitted, so the
@@ -162,9 +165,19 @@ export const isRetryable = (err: unknown): boolean => {
 // Everything else is ambiguous. A 5xx proves the server did process the
 // request. A reset or a broken pipe can arrive after it was fully sent and
 // acted on. A routing errno can be delivered on an established socket. A
-// deadline says nothing at all about the server's state.
-export const isSafeToReplay = (err: unknown): boolean =>
-    isRetryable(err) && causeCodes(err).some((code) => CONNECT_CODES.has(code));
+// deadline says nothing at all about the server's state. So every errno in the
+// cause chain must be a connect errno: one other errno anywhere in the chain
+// is doubt, and doubt is not replayed. A chain longer than the walk is doubt
+// too: the links below the limit were never read.
+export const isSafeToReplay = (err: unknown): boolean => {
+    const { codes, complete } = causeCodes(err);
+    return (
+        isRetryable(err) &&
+        complete &&
+        codes.length > 0 &&
+        codes.every((code) => CONNECT_CODES.has(code))
+    );
+};
 
 export interface WithRetryOptions extends RetryOptions {
     isRetryable?: (err: unknown) => boolean;

src/thumbnails.ts

@@ -7,8 +7,21 @@ import { ApiError } from "./api/client.js";
 import { encryptBlob, toBase64 } from "./crypto/index.js";
 import type { EnteFile } from "./model/types.js";
 
-const THUMB_MAX_DIMENSION = 720;
-const THUMB_JPEG_QUALITY = 50;
+// The server refuses a thumbnail larger than the one it already records for the
+// file (`thumbnail.size`, the encrypted size), so these encodings are tried
+// from largest to smallest and the first that fits is uploaded.
+const THUMB_ENCODINGS = [
+    { maxDimension: 720, quality: 50 },
+    { maxDimension: 720, quality: 30 },
+    { maxDimension: 480, quality: 30 },
+    { maxDimension: 320, quality: 20 },
+    { maxDimension: 160, quality: 20 },
+];
+
+// The server accepts a new thumbnail only from the file's owner, so files other
+// people own in albums shared with this account are never checked or repaired.
+const NOT_OWNED_REASON =
+    "owned by another account (only the owner can replace its thumbnail)";
 
 export interface MissingThumbnailInfo {
     fileID: number;
@@ -19,11 +32,12 @@ export interface MissingThumbnailInfo {
 
 // Three outcomes, not two. "fixed": a thumbnail was generated and uploaded.
 // "failed": something went wrong (download, encode, upload) and the file still
-// has no thumbnail. "skipped": the file is a format this helper cannot
-// regenerate — a video, or an image that is not a baseline JPEG. Skipped is a
-// deliberate, expected outcome, not an error (issue #17): the repair path is
-// JPEG-only because `jpeg-js` is, and a PNG or HEIC is left for a format-aware
-// tool rather than reported as a failure.
+// has no thumbnail. "skipped": the server would refuse any thumbnail for the
+// file or this helper cannot regenerate it — a file another account owns, a
+// recorded thumbnail size nothing fits within, a video, or an image that is
+// not a baseline JPEG. Skipped is a deliberate, expected outcome, not an error
+// (issue #17): the repair path is JPEG-only because `jpeg-js` is, and a PNG or
+// HEIC is left for a format-aware tool rather than reported as a failure.
 export type ThumbnailFixStatus = "fixed" | "skipped" | "failed";
 
 export interface ThumbnailFixResult {
@@ -45,6 +59,7 @@ export type ProgressCallback = (message: string) => void;
 // exists, so it is logged and the file is left unreported. That distinction is
 // what stops `fix-missing-thumbnails` from regenerating and uploading over
 // thumbnails that were fine all along while the CDN was briefly returning 500s.
+// Files another account owns are logged as skipped and not checked.
 export const listMissingThumbnails = async (
     lib: Library,
     client: Client,
@@ -52,6 +67,7 @@ export const listMissingThumbnails = async (
 ): Promise<MissingThumbnailInfo[]> => {
     const log = onProgress ?? (() => {});
     const api = client.getApiClient();
+    const { userID } = client.whoami();
     const missing: MissingThumbnailInfo[] = [];
     const seen = new Set<number>();
 
@@ -60,6 +76,13 @@ export const listMissingThumbnails = async (
         for (const photo of album.photos.list()) {
             if (seen.has(photo.fileID)) continue;
             seen.add(photo.fileID);
+            const file = lib.getFile(album.collectionID, photo.fileID);
+            if (file && file.ownerID !== userID) {
+                log(
+                    `[${album.name}] Skipping ${photo.title}: ${NOT_OWNED_REASON}`,
+                );
+                continue;
+            }
             try {
                 const stream = await api.getThumbnailStream(photo.fileID);
                 const reader = stream.getReader();
@@ -135,17 +158,13 @@ const resizeRGBA = (
     return dst;
 };
 
-const generateThumbnail = (fileBytes: Uint8Array): Uint8Array => {
-    const decoded = jpeg.decode(fileBytes, {
-        useTArray: true,
-        formatAsRGBA: true,
-    });
+const generateThumbnail = (
+    decoded: { data: Uint8Array; width: number; height: number },
+    maxDimension: number,
+    quality: number,
+): Uint8Array => {
     const { width: srcW, height: srcH } = decoded;
-    const scale = Math.min(
-        THUMB_MAX_DIMENSION / srcW,
-        THUMB_MAX_DIMENSION / srcH,
-        1,
-    );
+    const scale = Math.min(maxDimension / srcW, maxDimension / srcH, 1);
     const dstW = Math.round(srcW * scale);
     const dstH = Math.round(srcH * scale);
 
@@ -158,7 +177,7 @@ const generateThumbnail = (fileBytes: Uint8Array): Uint8Array => {
 
     const encoded = jpeg.encode(
         { data: pixels, width: dstW, height: dstH },
-        THUMB_JPEG_QUALITY,
+        quality,
     );
     return new Uint8Array(encoded.data);
 };
@@ -171,14 +190,35 @@ const generateThumbnail = (fileBytes: Uint8Array): Uint8Array => {
 const isJpeg = (bytes: Uint8Array): boolean =>
     bytes.length >= 2 && bytes[0] === 0xff && bytes[1] === 0xd8;
 
-// The reason a file cannot have a JPEG thumbnail regenerated for it from its
-// metadata alone, before any bytes are fetched, or undefined when it might. A
-// non-image (video, live photo) is unsupported outright; a still image still
-// has to be checked against its actual bytes once downloaded.
-const unsupportedByType = (file: EnteFile): string | undefined => {
+// The reason a file cannot have a JPEG thumbnail regenerated for it, known from
+// its record alone before any bytes are fetched, or undefined when it might. A
+// still image still has to be checked against its actual bytes once
+// downloaded.
+const reasonToSkip = (file: EnteFile, userID: number): string | undefined => {
+    if (file.ownerID !== userID) {
+        return NOT_OWNED_REASON;
+    }
     if (file.metadata.fileType !== "image") {
         return `unsupported file type: ${file.metadata.fileType} (only JPEG images can be regenerated)`;
     }
+    if (!file.thumbnail.size) {
+        return `recorded thumbnail size is ${file.thumbnail.size ?? "unknown"} (the server refuses a thumbnail larger than the one it records)`;
+    }
+    return undefined;
+};
+
+// Encrypt the largest encoding of the decoded image whose ciphertext is no
+// larger than `maxSize`, or return undefined when even the smallest is larger.
+const encryptThumbnailWithin = (
+    decoded: { data: Uint8Array; width: number; height: number },
+    key: Uint8Array,
+    maxSize: number,
+): { header: Uint8Array; ciphertext: Uint8Array } | undefined => {
+    for (const { maxDimension, quality } of THUMB_ENCODINGS) {
+        const thumbJpeg = generateThumbnail(decoded, maxDimension, quality);
+        const encrypted = encryptBlob(thumbJpeg, key);
+        if (encrypted.ciphertext.length <= maxSize) return encrypted;
+    }
     return undefined;
 };
 
@@ -197,6 +237,7 @@ export const fixMissingThumbnails = async (
     const log = onProgress ?? (() => {});
     const results: ThumbnailFixResult[] = [];
     const api = client.getApiClient();
+    const { userID } = client.whoami();
 
     // Resolve each requested fileID to its file record and owning album by
     // enumerating the library, each file taken from the first album that holds
@@ -237,18 +278,19 @@ export const fixMissingThumbnails = async (
         const { file, collectionName } = entry;
         const title = file.metadata.title;
 
-        const typeReason = unsupportedByType(file);
-        if (typeReason) {
-            log(`[${collectionName}] Skipping ${title}: ${typeReason}`);
+        const skipReason = reasonToSkip(file, userID);
+        if (skipReason) {
+            log(`[${collectionName}] Skipping ${title}: ${skipReason}`);
             results.push({
                 fileID,
                 title,
                 collection: collectionName,
                 status: "skipped",
-                reason: typeReason,
+                reason: skipReason,
             });
             continue;
         }
+        const maxSize = file.thumbnail.size!;
 
         try {
             const photo = lib.photos.byID({ fileID });
@@ -277,12 +319,28 @@ export const fixMissingThumbnails = async (
             }
 
             log(`[${collectionName}] Generating thumbnail for ${title}...`);
-            const thumbJpeg = generateThumbnail(fileBytes);
+            const decoded = jpeg.decode(fileBytes, {
+                useTArray: true,
+                formatAsRGBA: true,
+            });
+            const fitting = encryptThumbnailWithin(decoded, file.key, maxSize);
+            if (!fitting) {
+                const reason = `no thumbnail encoding fits the recorded thumbnail size of ${maxSize} bytes`;
+                log(`[${collectionName}] Skipping ${title}: ${reason}`);
+                results.push({
+                    fileID,
+                    title,
+                    collection: collectionName,
+                    status: "skipped",
+                    reason,
+                });
+                continue;
+            }
+            const { header, ciphertext } = fitting;
 
             log(
-                `[${collectionName}] Encrypting and uploading thumbnail (${thumbJpeg.length} bytes)...`,
+                `[${collectionName}] Uploading thumbnail (${ciphertext.length} bytes)...`,
             );
-            const { header, ciphertext } = encryptBlob(thumbJpeg, file.key);
             const md5 = createHash("md5").update(ciphertext).digest("base64");
             const { objectKey, url } = await api.getUploadURL(
                 ciphertext.length,

test/api/client.test.ts

@@ -38,14 +38,18 @@
  * the network. The fake records every call for assertion.
  */
 
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import {
     ApiClient,
     ApiError,
     DEFAULT_DOWNLOAD_TIMEOUT_MS,
     DEFAULT_REQUEST_TIMEOUT_MS,
 } from "../../src/api/client.js";
-import type { RetryOptions } from "../../src/retry.js";
+import {
+    isRetryable,
+    isSafeToReplay,
+    type RetryOptions,
+} from "../../src/retry.js";
 
 // ---------------------------------------------------------------------------
 // Test helpers
@@ -385,6 +389,103 @@ describe("ApiClient custom origins", () => {
     });
 });
 
+describe("ApiClient request URLs", () => {
+    it("accepts a path with or without a leading slash", async () => {
+        const { fetch, calls } = recordingFetch(
+            jsonResponse({}),
+            jsonResponse({}),
+            jsonResponse({}),
+        );
+        const client = new ApiClient({ fetch });
+        await client.getJSON("health");
+        await client.postJSON("users/ott", {});
+        await client.putJSON("/files/thumbnail", {});
+
+        expect(calls.map((c) => c.url)).toEqual([
+            "https://api.ente.io/health",
+            "https://api.ente.io/users/ott",
+            "https://api.ente.io/files/thumbnail",
+        ]);
+    });
+
+    it("accepts an apiOrigin with a trailing slash", async () => {
+        const { fetch, calls } = recordingFetch(jsonResponse({}));
+        const client = new ApiClient({
+            fetch,
+            apiOrigin: "https://my-ente.example.com/",
+        });
+        await client.getJSON("/health");
+
+        expect(calls[0]!.url).toBe("https://my-ente.example.com/health");
+    });
+
+    it("keeps a base path in a self-hosted apiOrigin for every request", async () => {
+        const body = new Uint8Array([1]);
+        const { fetch, calls } = recordingFetch(
+            jsonResponse({}),
+            jsonResponse({}),
+            jsonResponse({}),
+            streamResponse(body),
+            streamResponse(body),
+        );
+        const client = new ApiClient({
+            fetch,
+            apiOrigin: "https://example.com/ente/",
+        });
+        await client.getJSON("/collections/v2", { sinceTime: 0 });
+        await client.postJSON("/users/ott", {});
+        await client.putJSON("/files/thumbnail", {});
+        await client.getFileStream(99);
+        await client.getThumbnailStream(77);
+
+        expect(calls.map((c) => c.url)).toEqual([
+            "https://example.com/ente/collections/v2?sinceTime=0",
+            "https://example.com/ente/users/ott",
+            "https://example.com/ente/files/thumbnail",
+            "https://example.com/ente/files/download/99",
+            "https://example.com/ente/files/preview/77",
+        ]);
+    });
+
+    it("percent-encodes query parameters and skips undefined ones", async () => {
+        const { fetch, calls } = recordingFetch(jsonResponse({}));
+        const client = new ApiClient({ fetch });
+        await client.getJSON("/search", {
+            q: "a&b=c/d é",
+            limit: 5,
+            cursor: undefined,
+        });
+
+        const url = new URL(calls[0]!.url);
+        expect(url.pathname).toBe("/search");
+        expect(url.search).toBe("?q=a%26b%3Dc%2Fd+%C3%A9&limit=5");
+        expect(url.searchParams.get("q")).toBe("a&b=c/d é");
+    });
+
+    it("rejects a path that carries its own query string", async () => {
+        const { fetch, calls } = recordingFetch();
+        const client = new ApiClient({ fetch });
+
+        await expect(client.getJSON("/diff?sinceTime=0")).rejects.toThrow(
+            /must not contain "\?"/,
+        );
+        await expect(client.postJSON("/users/ott?x=1", {})).rejects.toThrow(
+            /must not contain "\?"/,
+        );
+        expect(calls).toHaveLength(0);
+    });
+
+    it("rejects a path that carries a fragment", async () => {
+        const { fetch, calls } = recordingFetch();
+        const client = new ApiClient({ fetch });
+
+        await expect(client.getJSON("/diff#top")).rejects.toThrow(
+            /must not contain "\?" or "#"/,
+        );
+        expect(calls).toHaveLength(0);
+    });
+});
+
 describe("ApiError", () => {
     it("throws ApiError on 4xx with status, code, requestID", async () => {
         const { fetch } = recordingFetch(
@@ -639,17 +740,33 @@ describe("ApiClient retries", () => {
         expect(policy.baseDelayMs).toBe(7);
         expect(policy.maxDelayMs).toBe(11);
     });
+
+    it("does not let a caller change its settings through that policy", async () => {
+        const { fetch, calls } = scriptedFetch(
+            textResponse("boom", 500),
+            textResponse("boom", 500),
+            textResponse("boom", 500),
+        );
+        const client = new ApiClient({
+            fetch,
+            retry: { ...noWait, attempts: 2 },
+        });
+
+        client.getRetryOptions().attempts = 3;
+
+        expect(client.getRetryOptions().attempts).toBe(2);
+        await expect(client.getJSON("/x")).rejects.toBeInstanceOf(ApiError);
+        expect(calls).toHaveLength(2);
+    });
 });
 
 describe("ApiClient timeouts", () => {
     it("ships bounded default deadlines", () => {
-        // Asserted here so the README and the code cannot drift. Two numbers
-        // rather than one, because a deadline that is sane for a JSON call is
-        // nowhere near enough for a multi-gigabyte body, and a deadline long
-        // enough for that body would let a hung API call stall a backup for
-        // ten minutes.
+        // Asserted here so the README and the code cannot drift. The request
+        // deadline bounds a whole JSON call; the download deadline is an idle
+        // one, measured from the last byte that arrived.
         expect(DEFAULT_REQUEST_TIMEOUT_MS).toBe(30_000);
-        expect(DEFAULT_DOWNLOAD_TIMEOUT_MS).toBe(600_000);
+        expect(DEFAULT_DOWNLOAD_TIMEOUT_MS).toBe(60_000);
     });
 
     it("attaches an abort signal to every request", async () => {
@@ -693,6 +810,51 @@ describe("ApiClient timeouts", () => {
         expect(new Set(signals).size).toBe(3);
     }, 5000);
 
+    it("gives every retrying entry point a fresh deadline per attempt", async () => {
+        // A refused connection is retried by every entry point, the
+        // non-idempotent ones included. If the deadline were created once,
+        // outside the retry, both attempts would carry the same signal.
+        const entryPoints: [
+            string,
+            () => Response,
+            (c: ApiClient) => unknown,
+        ][] = [
+            ["getJSON", () => jsonResponse({}), (c) => c.getJSON("/a")],
+            ["postJSON", () => jsonResponse({}), (c) => c.postJSON("/b", {})],
+            ["putJSON", () => jsonResponse({}), (c) => c.putJSON("/c", {})],
+            [
+                "putFile",
+                () => new Response(null, { status: 200 }),
+                (c) => c.putFile("https://s3.example/x", new Uint8Array([1])),
+            ],
+            [
+                "getFileStream",
+                () => streamResponse(new Uint8Array([1])),
+                (c) => c.getFileStream(1),
+            ],
+            [
+                "getThumbnailStream",
+                () => streamResponse(new Uint8Array([1])),
+                (c) => c.getThumbnailStream(1),
+            ],
+        ];
+        for (const [name, success, call] of entryPoints) {
+            const { fetch, calls } = scriptedFetch(
+                errnoError("ECONNREFUSED", "connect ECONNREFUSED"),
+                success(),
+            );
+            const client = new ApiClient({ fetch, retry: noWait });
+
+            await call(client);
+
+            expect(calls, name).toHaveLength(2);
+            const [first, second] = calls.map((c) => c.init?.signal);
+            expect(first, name).toBeInstanceOf(AbortSignal);
+            expect(second, name).toBeInstanceOf(AbortSignal);
+            expect(second, name).not.toBe(first);
+        }
+    });
+
     it("recovers when a later attempt answers in time", async () => {
         const { fetch, calls } = scriptedFetch(HANG, jsonResponse({ ok: 1 }));
         const client = new ApiClient({
@@ -718,25 +880,91 @@ describe("ApiClient timeouts", () => {
         // that never produces a chunk and never observes the signal, so the
         // only thing that can unblock the read is quak's own enforcement of
         // the deadline over the stream it hands out.
-        const stalling = new Response(
-            new ReadableStream<Uint8Array>({
-                pull: () => new Promise<void>(() => {}),
-            }),
-            { status: 200 },
-        );
-        const { fetch } = scriptedFetch(stalling);
-        const client = new ApiClient({
-            fetch,
-            downloadTimeoutMs: 20,
-            retry: { ...noWait, attempts: 1 },
-        });
+        //
+        // The clock is faked, so the test runs under the real default
+        // deadline and waits for nothing.
+        vi.useFakeTimers();
+        try {
+            const stalling = new Response(
+                new ReadableStream<Uint8Array>({
+                    pull: () => new Promise<void>(() => {}),
+                }),
+                { status: 200 },
+            );
+            const { fetch } = scriptedFetch(stalling);
+            const client = new ApiClient({
+                fetch,
+                retry: { ...noWait, attempts: 1 },
+            });
 
-        const stream = await client.getFileStream(42);
-        const err: unknown = await readAll(stream).catch((e: unknown) => e);
+            const stream = await client.getFileStream(42);
+            let settled = false;
+            const result = readAll(stream).then(
+                (n) => n,
+                (e: unknown) => e,
+            );
+            void result.finally(() => {
+                settled = true;
+            });
 
-        expect(err).toBeInstanceOf(Error);
-        expect((err as Error).name).toBe("TimeoutError");
-    }, 5000);
+            await vi.advanceTimersByTimeAsync(DEFAULT_DOWNLOAD_TIMEOUT_MS - 1);
+            expect(settled).toBe(false);
+            await vi.advanceTimersByTimeAsync(1);
+
+            const err = await result;
+            expect(err).toBeInstanceOf(Error);
+            expect((err as Error).name).toBe("TimeoutError");
+            // Classified as every deadline is: retried by the idempotent
+            // downloads, never replayed for a POST or PUT.
+            expect(isRetryable(err)).toBe(true);
+            expect(isSafeToReplay(err)).toBe(false);
+        } finally {
+            vi.useRealTimers();
+        }
+    });
+
+    it("does not abort a slow body that keeps making progress", async () => {
+        // A deadline over the whole transfer would cut off a large video on a
+        // slow link however steadily it was arriving. The deadline restarts
+        // with every chunk, so a body that sends one byte every 600 ms for
+        // well over the 1000 ms deadline completes.
+        vi.useFakeTimers();
+        try {
+            let sent = 0;
+            const trickling = new Response(
+                new ReadableStream<Uint8Array>({
+                    async pull(controller) {
+                        await new Promise((resolve) =>
+                            setTimeout(resolve, 600),
+                        );
+                        if (sent === 10) {
+                            controller.close();
+                            return;
+                        }
+                        controller.enqueue(new Uint8Array([sent++]));
+                    },
+                }),
+                { status: 200 },
+            );
+            const { fetch } = scriptedFetch(trickling);
+            const client = new ApiClient({
+                fetch,
+                downloadTimeoutMs: 1000,
+                retry: { ...noWait, attempts: 1 },
+            });
+
+            const stream = await client.getFileStream(42);
+            const result = readAll(stream).then(
+                (n) => n,
+                (e: unknown) => e,
+            );
+            await vi.advanceTimersByTimeAsync(11 * 600);
+
+            expect(await result).toBe(10);
+        } finally {
+            vi.useRealTimers();
+        }
+    });
 
     it("lets a body that arrives in time through untouched", async () => {
         // The counterpart to the previous test: enforcing the deadline over
@@ -762,6 +990,52 @@ describe("ApiClient timeouts", () => {
         }
         expect(joined).toEqual(payload);
     });
+
+    it("leaves no timer pending after a download completes or fails", async () => {
+        vi.useFakeTimers();
+        try {
+            const { fetch } = scriptedFetch(
+                streamResponse(new Uint8Array([1, 2, 3])),
+                textResponse("gone", 404),
+            );
+            const client = new ApiClient({
+                fetch,
+                retry: { ...noWait, attempts: 1 },
+            });
+
+            expect(await readAll(await client.getFileStream(1))).toBe(3);
+            expect(vi.getTimerCount()).toBe(0);
+
+            await expect(client.getFileStream(2)).rejects.toBeInstanceOf(
+                ApiError,
+            );
+            expect(vi.getTimerCount()).toBe(0);
+        } finally {
+            vi.useRealTimers();
+        }
+    });
+
+    it("never lets the download timer keep the process alive", async () => {
+        const spy = vi.spyOn(globalThis, "setTimeout");
+        try {
+            const { fetch } = scriptedFetch(
+                streamResponse(new Uint8Array([1])),
+            );
+            const client = new ApiClient({
+                fetch,
+                downloadTimeoutMs: 12_345,
+                retry: noWait,
+            });
+
+            const stream = await client.getFileStream(1);
+            const i = spy.mock.calls.findIndex((call) => call[1] === 12_345);
+            const timer = spy.mock.results[i]!.value as NodeJS.Timeout;
+            expect(timer.hasRef()).toBe(false);
+            await stream.cancel();
+        } finally {
+            spy.mockRestore();
+        }
+    });
 });
 
 describe("ApiClient error typing", () => {
@@ -820,9 +1094,8 @@ describe("ApiClient error typing", () => {
 
 describe("ApiClient non-idempotent requests", () => {
     /**
-     * `postJSON` and `putJSON` carry quak's only requests that change server
-     * state: `/users/srp/create-session`, `/users/two-factor/verify` — which
-     * consumes one of a small number of 2FA attempts — and `/files/thumbnail`.
+     * `postJSON` and `putJSON` carry quak's requests that can change server
+     * state; the README lists them under "Endpoints used".
      *
      * They are retried only on a failure that establishes no TCP connection to
      * the server ever existed — DNS produced no address, or the peer refused
@@ -922,4 +1195,30 @@ describe("ApiClient non-idempotent requests", () => {
         await refusedClient.updateThumbnail(1, "key", "header");
         expect(refused.calls).toHaveLength(2);
     });
+
+    it("does not follow or replay a redirect on POST or PUT", async () => {
+        // The origin has already received a request it answers with a
+        // redirect, so following it would let a refused connection to the
+        // redirect target pass for a request that never went out.
+        for (const send of [
+            (c: ApiClient) => c.postJSON("/users/ott", {}),
+            (c: ApiClient) => c.putJSON("/files/thumbnail", {}),
+        ]) {
+            const { fetch, calls } = scriptedFetch(
+                new Response(null, {
+                    status: 307,
+                    headers: { location: "https://elsewhere.example/" },
+                }),
+                jsonResponse({}),
+            );
+            const client = new ApiClient({ fetch, retry: noWait });
+
+            const err: unknown = await send(client).catch((e: unknown) => e);
+
+            expect(calls[0]?.init?.redirect).toBe("manual");
+            expect(err).toBeInstanceOf(ApiError);
+            expect((err as ApiError).status).toBe(307);
+            expect(calls).toHaveLength(1);
+        }
+    });
 });

test/cli/backup.test.ts

@@ -40,16 +40,54 @@ import {
     readFileSync,
     readlinkSync,
     rmSync,
+    symlinkSync,
     writeFileSync,
 } from "node:fs";
+import { spawnSync } from "node:child_process";
 import { join } from "node:path";
 import { tmpdir } from "node:os";
-import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 
+import { runBackup, type BackupLibrary } from "../../src/backup.js";
 import { Library } from "../../src/library/index.js";
 import type { ContentSource } from "../../src/library/content.js";
 import type { CollectionsPage, FilesPage } from "../../src/client.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
+import {
+    asLivePhoto,
+    cdnSource,
+    IMAGE,
+    livePhotoZip,
+    VIDEO,
+} from "../live-photo.js";
+
+// `open` and `rename` are wrapped to record, in order, every fsync and rename,
+// so a test can pin the sequence "fsync the temp file, rename, fsync the
+// directory" that makes a copied original survive a power cut. `vi.hoisted`
+// because `vi.mock` factories run before module-level constants exist.
+const fsEvents = vi.hoisted(() => [] as string[]);
+
+vi.mock("node:fs/promises", async (importOriginal) => {
+    const actual = await importOriginal<typeof import("node:fs/promises")>();
+    return {
+        ...actual,
+        open: async (
+            ...args: Parameters<typeof actual.open>
+        ): Promise<Awaited<ReturnType<typeof actual.open>>> => {
+            const handle = await actual.open(...args);
+            const realSync = handle.sync.bind(handle);
+            handle.sync = async (): Promise<void> => {
+                fsEvents.push(`sync:${String(args[0])}`);
+                await realSync();
+            };
+            return handle;
+        },
+        rename: async (from: string, to: string): Promise<void> => {
+            fsEvents.push(`rename:${to}`);
+            await actual.rename(from, to);
+        },
+    };
+});
 
 const USER_ID = 42;
 
@@ -530,4 +568,683 @@ describe("lib.backup", () => {
         expect(readLedger(outDir).files["101"]!.attempts).toBe(1);
         lib.close();
     });
+
+    it("fetches each original once and writes it only into the backup", async () => {
+        // A backup of a 500 GB account must write 500 GB, not a copy in the
+        // cache as well: an original fetched for the backup goes straight
+        // into its originals/, and the cache records it there.
+        const source = stubSource();
+        const lib = await openLibrary(source);
+        const outDir = join(root, "backup");
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result.downloaded).toBe(3);
+        expect(source.originalCalls).toBe(3);
+        expect(readdirSync(join(root, "cache", "originals"))).toEqual([]);
+        const stored = readdirSync(join(outDir, "originals")).filter(
+            (name) => !name.endsWith(".json"),
+        );
+        expect(stored.sort()).toEqual(["100.jpg", "101.jpg", "200.png"]);
+        // The cache counts the backup's copy as present: reading the
+        // original afterwards fetches nothing and answers with that copy.
+        const read = await lib.photos.byID({ fileID: 100 })!.original();
+        expect(read.path).toBe(join(outDir, "originals", "100.jpg"));
+        expect(source.originalCalls).toBe(3);
+        await lib.close();
+    });
+
+    it("fsyncs an original copied from the cache before the rename and its directory after", async () => {
+        const lib = await openLibrary(stubSource());
+        const outDir = join(root, "backup");
+        const originals = join(outDir, "originals");
+        const dest = join(originals, "100.jpg");
+        // Only an original already in the cache is copied into the backup;
+        // one fetched for the backup is written there by the download writer.
+        await lib.photos.byID({ fileID: 100 })!.original();
+        fsEvents.length = 0;
+
+        await lib.backup({ downloadDirectory: outDir });
+
+        const at = fsEvents.indexOf(`rename:${dest}`);
+        expect(at).toBeGreaterThan(0);
+        expect(fsEvents[at - 1]).toMatch(
+            /^sync:.*\/\.quak-backup-100\.jpg-\d+-[0-9a-z]*\.tmp$/,
+        );
+        expect(fsEvents[at + 1]).toBe(`sync:${originals}`);
+        lib.close();
+    });
+
+    it("removes temp files left by a killed backup but not those of one still running", async () => {
+        const outDir = join(root, "backup");
+        const originals = join(outDir, "originals");
+        mkdirSync(originals, { recursive: true });
+        // A child that has already exited: its process ID is not running.
+        const exitedPID = spawnSync(process.execPath, ["-e", ""]).pid;
+        const leftover = `.quak-backup-100.jpg-${exitedPID}-abc123.tmp`;
+        // This test's own process stands in for a backup running at the same
+        // time.
+        const inProgress = `.quak-backup-101.jpg-${process.pid}-def456.tmp`;
+        writeFileSync(join(originals, leftover), "partial");
+        writeFileSync(join(originals, inProgress), "partial");
+        const lib = await openLibrary(stubSource());
+
+        await lib.backup({ downloadDirectory: outDir });
+
+        const names = readdirSync(originals);
+        expect(names).not.toContain(leftover);
+        expect(names).toContain(inProgress);
+        lib.close();
+    });
+
+    it("removes leftover temp files in thumbnails/ but not those of a backup still running", async () => {
+        const outDir = join(root, "backup");
+        const thumbnails = join(outDir, "thumbnails");
+        mkdirSync(thumbnails, { recursive: true });
+        const exitedPID = spawnSync(process.execPath, ["-e", ""]).pid;
+        const leftover = `.quak-backup-100.jpg-${exitedPID}-abc123.tmp`;
+        const inProgress = `.quak-backup-101.jpg-${process.pid}-def456.tmp`;
+        writeFileSync(join(thumbnails, leftover), "partial");
+        writeFileSync(join(thumbnails, inProgress), "partial");
+        const lib = await openLibrary(stubSource());
+
+        await lib.backup({
+            downloadDirectory: outDir,
+            includeThumbnails: true,
+        });
+
+        const names = readdirSync(thumbnails);
+        expect(names).not.toContain(leftover);
+        expect(names).toContain(inProgress);
+        lib.close();
+    });
+});
+
+// Every refresh fails, as with an expired session or no network.
+class FailingClient extends MockClient {
+    override async collectionsSince(): Promise<CollectionsPage> {
+        throw new Error("HTTP 401 from server");
+    }
+}
+
+// Holds its refresh open until `release()` is called, then reports a third
+// album, so a backup can be started while that refresh is still running.
+class HeldClient extends MockClient {
+    release!: () => void;
+    private held = new Promise<void>((resolve) => {
+        this.release = resolve;
+    });
+    override async collectionsSince(): Promise<CollectionsPage> {
+        await this.held;
+        return {
+            collections: [collection(3, "Later")],
+            deleted: [],
+            cursor: 2,
+        };
+    }
+    override async filesSince(args: {
+        collectionID: number;
+    }): Promise<FilesPage> {
+        if (args.collectionID !== 3) return super.filesSince(args);
+        return { files: [file(300, 3, "late.jpg")], deleted: [], cursor: 2 };
+    }
+}
+
+// Fill the library cache on disk, so the next open starts its refresh in the
+// background instead of waiting for it.
+const fillCache = async (): Promise<void> => {
+    const lib = await openLibrary(stubSource());
+    await lib.close();
+};
+
+describe("the refresh before a backup", () => {
+    it("waits for a refresh already running and backs up what it found", async () => {
+        await fillCache();
+        const client = new HeldClient();
+        const lib = await openLibrary(stubSource(), client);
+        const outDir = join(root, "backup");
+
+        const backup = lib.backup({ downloadDirectory: outDir });
+        client.release();
+        const result = await backup;
+
+        expect(result.totalFiles).toBe(4);
+        expect(existsSync(join(outDir, "originals", "300.jpg"))).toBe(true);
+        await lib.close();
+    });
+
+    it("fails before any download when the refresh fails, leaving failures.json as it was", async () => {
+        await fillCache();
+        const outDir = join(root, "backup");
+        seedLedger(outDir, 100, "beach.jpg");
+        const ledgerPath = join(outDir, "failures.json");
+        const ledgerBefore = readFileSync(ledgerPath, "utf-8");
+        const source = stubSource();
+        const lib = await openLibrary(source, new FailingClient());
+
+        await expect(lib.backup({ downloadDirectory: outDir })).rejects.toThrow(
+            "HTTP 401 from server",
+        );
+
+        expect(source.originalCalls).toBe(0);
+        expect(readFileSync(ledgerPath, "utf-8")).toBe(ledgerBefore);
+        expect(existsSync(join(outDir, "originals"))).toBe(false);
+        await lib.close();
+    });
+
+    it("fails when the refresh fails on an empty cache, instead of backing up nothing", async () => {
+        const source = stubSource();
+        const lib = await openLibrary(source, new FailingClient());
+        const outDir = join(root, "backup");
+
+        await expect(lib.backup({ downloadDirectory: outDir })).rejects.toThrow(
+            "HTTP 401 from server",
+        );
+
+        expect(source.originalCalls).toBe(0);
+        expect(existsSync(outDir)).toBe(false);
+        await lib.close();
+    });
+});
+
+// Every entry under collections/, one level of directories deep, with each
+// symlink's target.
+const tree = (outDir: string): string[] => {
+    const lines: string[] = [];
+    const list = (dir: string, prefix: string): void => {
+        for (const name of readdirSync(dir).sort()) {
+            const path = join(dir, name);
+            const st = lstatSync(path);
+            if (st.isSymbolicLink()) {
+                lines.push(`${prefix}${name} -> ${readlinkSync(path)}`);
+            } else if (st.isDirectory() && prefix === "") {
+                lines.push(`${name}/`);
+                list(path, `${name}/`);
+            } else {
+                lines.push(`${prefix}${name}`);
+            }
+        }
+    };
+    list(join(outDir, "collections"), "");
+    return lines;
+};
+
+// The album folders under collections/, driven through `runBackup` with a
+// stand-in library whose albums a test changes between runs.
+describe("backup album folders", () => {
+    interface Album {
+        collection: Collection;
+        files: EnteFile[];
+    }
+
+    const libraryOf = (albums: Album[]): BackupLibrary => ({
+        refresh: async () => {},
+        listCollections: () => albums.map((a) => a.collection),
+        listFiles: (id) =>
+            albums.find((a) => a.collection.id === id)?.files ?? [],
+        original: async (fileID) => {
+            const path = join(root, `source-${fileID}`);
+            writeFileSync(path, `original ${fileID}`);
+            return { path };
+        },
+        thumbnail: async () => {
+            throw new Error("no thumbnails in this stand-in");
+        },
+    });
+
+    const albumID = (outDir: string, jsonName: string): number =>
+        JSON.parse(readFileSync(join(outDir, "collections", jsonName), "utf-8"))
+            .id;
+
+    it("gives every file and every album its own name when names repeat", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, "IMG_0001.JPG"),
+                    file(2, 10, "IMG_0001.JPG"),
+                    file(4, 10, "img_0001.jpg"),
+                    file(3, 10, "other.jpg"),
+                ],
+            },
+            {
+                collection: collection(11, "Trip"),
+                files: [file(3, 11, "other.jpg")],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip (10)/",
+            "Trip (10)/IMG_0001 (1).JPG -> ../../originals/1.JPG",
+            "Trip (10)/IMG_0001 (2).JPG -> ../../originals/2.JPG",
+            "Trip (10)/img_0001 (4).jpg -> ../../originals/4.jpg",
+            "Trip (10)/other.jpg -> ../../originals/3.jpg",
+            "Trip (10).json",
+            "Trip (11)/",
+            "Trip (11)/other.jpg -> ../../originals/3.jpg",
+            "Trip (11).json",
+        ]);
+        expect(albumID(outDir, "Trip (10).json")).toBe(10);
+        expect(albumID(outDir, "Trip (11).json")).toBe(11);
+    });
+
+    it("keeps names unique when a name with an ID added is another entry's own name", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(5, 10, "IMG (6).JPG"),
+                    file(6, 10, "IMG.JPG"),
+                    file(7, 10, "IMG.JPG"),
+                ],
+            },
+            {
+                collection: collection(11, "Trip"),
+                files: [file(8, 11, "a.jpg")],
+            },
+            {
+                collection: collection(12, "Trip (11)"),
+                files: [file(9, 12, "b.jpg")],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip (10)/",
+            "Trip (10)/IMG (6) (5).JPG -> ../../originals/5.JPG",
+            "Trip (10)/IMG (6).JPG -> ../../originals/6.JPG",
+            "Trip (10)/IMG (7).JPG -> ../../originals/7.JPG",
+            "Trip (10).json",
+            "Trip (11)/",
+            "Trip (11)/a.jpg -> ../../originals/8.jpg",
+            "Trip (11) (12)/",
+            "Trip (11) (12)/b.jpg -> ../../originals/9.jpg",
+            "Trip (11) (12).json",
+            "Trip (11).json",
+        ]);
+        expect(albumID(outDir, "Trip (10).json")).toBe(10);
+        expect(albumID(outDir, "Trip (11).json")).toBe(11);
+        expect(albumID(outDir, "Trip (11) (12).json")).toBe(12);
+    });
+
+    it("changes nothing on a second run over an unchanged account", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, "IMG_0001.JPG"),
+                    file(2, 10, "IMG_0001.JPG"),
+                ],
+            },
+            {
+                collection: collection(11, "Trip"),
+                files: [file(3, 11, "other.jpg")],
+            },
+        ]);
+
+        await runBackup(lib, { downloadDirectory: outDir });
+        const before = tree(outDir);
+        const second = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(second.downloaded).toBe(0);
+        expect(second.failed).toBe(0);
+        expect(tree(outDir)).toEqual(before);
+    });
+
+    it("leaves the albums an onlyAlbumNames run skips as they were", async () => {
+        const outDir = join(root, "backup");
+        // "trip" is skipped by the scoped run but its name clashes with the
+        // in-scope "Trip", so "Trip" must keep its ID suffix.
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [file(1, 10, "a.jpg")],
+            },
+            {
+                collection: collection(11, "trip"),
+                files: [file(2, 11, "b.jpg")],
+            },
+            {
+                collection: collection(12, "Work"),
+                files: [file(3, 12, "c.jpg")],
+            },
+        ]);
+        const json = (name: string): string =>
+            readFileSync(join(outDir, "collections", name), "utf-8");
+
+        await runBackup(lib, { downloadDirectory: outDir });
+        const before = tree(outDir);
+        const skippedJSON = [json("trip (11).json"), json("Work.json")];
+        const scoped = await runBackup(lib, {
+            downloadDirectory: outDir,
+            onlyAlbumNames: ["Trip"],
+        });
+
+        expect(scoped.failed).toBe(0);
+        expect(before).toEqual([
+            "Trip (10)/",
+            "Trip (10)/a.jpg -> ../../originals/1.jpg",
+            "Trip (10).json",
+            "Work/",
+            "Work/c.jpg -> ../../originals/3.jpg",
+            "Work.json",
+            "trip (11)/",
+            "trip (11)/b.jpg -> ../../originals/2.jpg",
+            "trip (11).json",
+        ]);
+        expect(tree(outDir)).toEqual(before);
+        expect([json("trip (11).json"), json("Work.json")]).toEqual(
+            skippedJSON,
+        );
+    });
+
+    it("removes links and album folders that are gone, and nothing the user added", async () => {
+        const outDir = join(root, "backup");
+        const albums: Album[] = [
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, "IMG_0001.JPG"),
+                    file(2, 10, "IMG_0001.JPG"),
+                    file(3, 10, "other.jpg"),
+                ],
+            },
+            {
+                collection: collection(12, "Work"),
+                files: [file(5, 12, "a.jpg")],
+            },
+            {
+                collection: collection(13, "Old"),
+                files: [file(5, 13, "a.jpg")],
+            },
+        ];
+        const lib = libraryOf(albums);
+        await runBackup(lib, { downloadDirectory: outDir });
+
+        // What the user put in the tree: a note and a symlink of their own in
+        // an album, a note in an album about to be renamed, and a folder quak
+        // did not create.
+        const collectionsDir = join(outDir, "collections");
+        writeFileSync(join(collectionsDir, "Trip", "notes.txt"), "mine");
+        symlinkSync("../elsewhere", join(collectionsDir, "Trip", "mine"));
+        writeFileSync(join(collectionsDir, "Work", "keep.txt"), "mine");
+        mkdirSync(join(collectionsDir, "Mine"));
+        writeFileSync(join(collectionsDir, "Mine", "keep.txt"), "mine");
+
+        // File 2 leaves Trip, Work is renamed Office, Old is deleted.
+        albums[0]!.files.splice(1, 1);
+        albums[1]!.collection = collection(12, "Office");
+        albums.splice(2, 1);
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Mine/",
+            "Mine/keep.txt",
+            "Office/",
+            "Office/a.jpg -> ../../originals/5.jpg",
+            "Office.json",
+            "Trip/",
+            "Trip/IMG_0001.JPG -> ../../originals/1.JPG",
+            "Trip/mine -> ../elsewhere",
+            "Trip/notes.txt",
+            "Trip/other.jpg -> ../../originals/3.jpg",
+            "Trip.json",
+            "Work/",
+            "Work/keep.txt",
+            "Work.json",
+        ]);
+    });
+
+    // One album backed up, then a folder the user made beside it holding a
+    // symlink into originals/, with `json` (if given) as its sibling JSON.
+    const backupWithUserFolder = async (
+        json: string | undefined,
+    ): Promise<{ outDir: string; failed: number }> => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [file(1, 10, "a.jpg")],
+            },
+        ]);
+        await runBackup(lib, { downloadDirectory: outDir });
+        const collectionsDir = join(outDir, "collections");
+        mkdirSync(join(collectionsDir, "Mine"));
+        symlinkSync(
+            "../../originals/1.jpg",
+            join(collectionsDir, "Mine", "a.jpg"),
+        );
+        if (json !== undefined) {
+            writeFileSync(join(collectionsDir, "Mine.json"), json);
+        }
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+        return { outDir, failed: result.failed };
+    };
+
+    it("leaves a user folder with no JSON beside it as it was", async () => {
+        const { outDir, failed } = await backupWithUserFolder(undefined);
+
+        expect(failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Mine/",
+            "Mine/a.jpg -> ../../originals/1.jpg",
+            "Trip/",
+            "Trip/a.jpg -> ../../originals/1.jpg",
+            "Trip.json",
+        ]);
+    });
+
+    it("leaves a user folder whose JSON has no album ID as it was", async () => {
+        const json = '{"name":"Mine"}';
+        const { outDir, failed } = await backupWithUserFolder(json);
+
+        expect(failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Mine/",
+            "Mine/a.jpg -> ../../originals/1.jpg",
+            "Mine.json",
+            "Trip/",
+            "Trip/a.jpg -> ../../originals/1.jpg",
+            "Trip.json",
+        ]);
+        expect(
+            readFileSync(join(outDir, "collections", "Mine.json"), "utf-8"),
+        ).toBe(json);
+    });
+});
+
+// A live photo, which Ente stores as one ZIP, is backed up as its image and
+// its video, which a photo viewer can open, beside a JSON file naming them,
+// and its album folder links both. These tests download a live photo ZIP
+// through the real download layer (test/live-photo.ts).
+describe("backup of live photos", () => {
+    // An account of one album, Trip (10), holding `files`.
+    class TripClient extends MockClient {
+        constructor(private readonly files: EnteFile[]) {
+            super();
+        }
+        override async collectionsSince(): Promise<CollectionsPage> {
+            return {
+                collections: [collection(10, "Trip")],
+                deleted: [],
+                cursor: 1,
+            };
+        }
+        override async filesSince(): Promise<FilesPage> {
+            return { files: this.files, deleted: [], cursor: 1 };
+        }
+    }
+
+    const open = (files: EnteFile[], bodies: Map<number, Uint8Array>) =>
+        openLibrary(cdnSource(bodies), new TripClient(files));
+
+    // What an earlier version stored for live photo 500: the ZIP under the
+    // image's name, and its link.
+    const earlierZIP = (outDir: string): void => {
+        mkdirSync(join(outDir, "originals"), { recursive: true });
+        mkdirSync(join(outDir, "collections", "Trip"), { recursive: true });
+        writeFileSync(join(outDir, "originals", "500.HEIC"), livePhotoZip());
+        symlinkSync(
+            "../../originals/500.HEIC",
+            join(outDir, "collections", "Trip", "IMG_0500.HEIC"),
+        );
+    };
+
+    const stored = ["500.heic", "500.json", "500.livephoto.json", "500.mov"];
+    const linked = [
+        "Trip/",
+        "Trip/IMG_0500.heic -> ../../originals/500.heic",
+        "Trip/IMG_0500.mov -> ../../originals/500.mov",
+        "Trip.json",
+    ];
+
+    it("stores a live photo as its image and its video and links both", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(500, 10, "IMG_0500.HEIC"),
+        );
+        const lib = await open([live], new Map([[500, body]]));
+        const outDir = join(root, "backup");
+        const originals = join(outDir, "originals");
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result).toMatchObject({ downloaded: 1, failed: 0 });
+        expect(readdirSync(originals).sort()).toEqual(stored);
+        expect(readFileSync(join(originals, "500.heic"))).toEqual(
+            Buffer.from(IMAGE),
+        );
+        expect(readFileSync(join(originals, "500.mov"))).toEqual(
+            Buffer.from(VIDEO),
+        );
+        expect(tree(outDir)).toEqual(linked);
+
+        // Both parts are there, so the next run fetches nothing.
+        const second = await lib.backup({ downloadDirectory: outDir });
+        expect(second).toMatchObject({ downloaded: 0, skipped: 1, failed: 0 });
+        await lib.close();
+    });
+
+    it("gives both links of each live photo their own names when titles clash", async () => {
+        const a = await asLivePhoto(file(500, 10, "IMG_0001.HEIC"));
+        const b = await asLivePhoto(file(501, 10, "IMG_0001.HEIC"));
+        const lib = await open(
+            [a.file, b.file],
+            new Map([
+                [500, a.body],
+                [501, b.body],
+            ]),
+        );
+        const outDir = join(root, "backup");
+
+        await lib.backup({ downloadDirectory: outDir });
+
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            "Trip/IMG_0001 (500).heic -> ../../originals/500.heic",
+            "Trip/IMG_0001 (500).mov -> ../../originals/500.mov",
+            "Trip/IMG_0001 (501).heic -> ../../originals/501.heic",
+            "Trip/IMG_0001 (501).mov -> ../../originals/501.mov",
+            "Trip.json",
+        ]);
+        await lib.close();
+    });
+
+    it("replaces the ZIP an earlier version stored, and its link", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(500, 10, "IMG_0500.HEIC"),
+        );
+        const outDir = join(root, "backup");
+        earlierZIP(outDir);
+        const lib = await open([live], new Map([[500, body]]));
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result).toMatchObject({ downloaded: 1, failed: 0 });
+        expect(readdirSync(join(outDir, "originals")).sort()).toEqual(stored);
+        expect(tree(outDir)).toEqual(linked);
+        await lib.close();
+    });
+
+    it("stores nothing for a live photo that fails its hash, and keeps what was there", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(500, 10, "IMG_0500.HEIC"),
+            livePhotoZip(),
+            "not:the recorded hash",
+        );
+        const outDir = join(root, "backup");
+        earlierZIP(outDir);
+        const lib = await open([live], new Map([[500, body]]));
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result).toMatchObject({ downloaded: 0, failed: 1 });
+        expect(result.errors.map((e) => e.fileID)).toEqual([500]);
+        expect(Object.keys(readLedger(outDir).files)).toEqual(["500"]);
+        expect(readdirSync(join(outDir, "originals"))).toEqual(["500.HEIC"]);
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            "Trip/IMG_0500.HEIC -> ../../originals/500.HEIC",
+            "Trip.json",
+        ]);
+        await lib.close();
+    });
+
+    it("copies both parts of a live photo the cache already holds", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(500, 10, "IMG_0500.HEIC"),
+        );
+        const lib = await open([live], new Map([[500, body]]));
+        const cached = await lib.photos.byID({ fileID: 500 })!.original();
+        const outDir = join(root, "backup");
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result).toMatchObject({ downloaded: 1, failed: 0 });
+        expect(readdirSync(join(outDir, "originals")).sort()).toEqual(stored);
+        expect(readFileSync(join(outDir, "originals", "500.mov"))).toEqual(
+            Buffer.from(VIDEO),
+        );
+        expect(tree(outDir)).toEqual(linked);
+        // The cache keeps its own copy.
+        expect(existsSync(cached.videoPath!)).toBe(true);
+        await lib.close();
+    });
+
+    it("serves a live photo the backup stored to a library reading the backup", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(500, 10, "IMG_0500.HEIC"),
+        );
+        const lib = await open([live], new Map([[500, body]]));
+        const outDir = join(root, "backup");
+        await lib.backup({ downloadDirectory: outDir });
+        await lib.close();
+
+        // Another cache over the same backup, whose server has nothing.
+        const reader = await Library.open({
+            client: new TripClient([live]),
+            cacheDirectory: join(root, "other-cache"),
+            downloadDirectory: outDir,
+            contentSource: cdnSource(new Map()),
+            refreshIntervalSeconds: 3600,
+            precacheThumbnails: false,
+            precacheOriginals: false,
+        });
+        const read = await reader.photos.byID({ fileID: 500 })!.original();
+
+        expect(read).toEqual({
+            path: join(outDir, "originals", "500.heic"),
+            videoPath: join(outDir, "originals", "500.mov"),
+            bytes: IMAGE.length,
+        });
+        await reader.close();
+    });
 });

test/cli/commands.test.ts

@@ -0,0 +1,856 @@
+/**
+ * Tests for the CLI commands (`src/cli-commands.ts`, issue #12).
+ *
+ * Each command is called directly with a context whose output streams collect
+ * text, whose session directory is a fresh temp directory, and whose session
+ * loader hands back a fake client. The fake serves two albums and three files
+ * from memory, writes stand-in bytes for originals and thumbnails, and makes no
+ * network calls. The helpers the commands call (`cli-read`, `cli-output`,
+ * backup, thumbnails) have their own tests; these check what each command
+ * prints and the exit code it returns.
+ */
+
+import {
+    existsSync,
+    mkdirSync,
+    mkdtempSync,
+    readdirSync,
+    readFileSync,
+    rmSync,
+    statSync,
+    writeFileSync,
+} from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { PassThrough } from "node:stream";
+import * as jpegJs from "jpeg-js";
+import {
+    describe,
+    it,
+    expect,
+    vi,
+    beforeAll,
+    beforeEach,
+    afterEach,
+} from "vitest";
+
+import {
+    type CliContext,
+    saveSession,
+    loginCommand,
+    whoamiCommand,
+    logoutCommand,
+    collectionsCommand,
+    filesCommand,
+    getCommand,
+    getThumbCommand,
+    backupCommand,
+    backupMetadataCommand,
+    listMissingThumbnailsCommand,
+    fixMissingThumbnailsCommand,
+} from "../../src/cli-commands.js";
+import { run } from "../../src/cli-run.js";
+import { loadSession } from "../../src/cli-session.js";
+import type { Client, ClientSnapshot, LoginOptions } from "../../src/client.js";
+import type { ContentSource } from "../../src/library/content.js";
+import type { Collection, EnteFile } from "../../src/model/types.js";
+import { init, toBase64 } from "../../src/crypto/index.js";
+import { defaultCacheDirectory } from "../../src/library/index.js";
+import {
+    asLivePhoto,
+    cdnSource,
+    IMAGE,
+    livePhotoHash,
+    livePhotoZip,
+    VIDEO,
+} from "../live-photo.js";
+
+const USER_ID = 42;
+
+const collection = (
+    id: number,
+    name: string,
+    isShared = false,
+): Collection => ({
+    id,
+    ownerID: USER_ID,
+    key: new Uint8Array([id]),
+    name,
+    type: "album",
+    updationTime: 1,
+    isShared,
+});
+
+const file = (id: number, collectionID: number, title: string): EnteFile => ({
+    id,
+    collectionID,
+    ownerID: USER_ID,
+    key: new Uint8Array([id & 0xff]),
+    metadata: {
+        title,
+        fileType: "image",
+        creationTime: 1000,
+        modificationTime: 1000,
+    },
+    file: { decryptionHeader: "aGVhZGVy" },
+    thumbnail: { decryptionHeader: "dGh1bWI=" },
+    updationTime: 1,
+});
+
+const COLLECTIONS = [collection(1, "Vacation"), collection(2, "Work", true)];
+
+const FILES: Record<number, EnteFile[]> = {
+    1: [file(100, 1, "beach.jpg"), file(101, 1, "sunset.jpg")],
+    2: [file(200, 2, "diagram.png")],
+};
+
+// An original is 7 bytes and a thumbnail 3. `failID` makes that file's
+// original fail; `emptyThumbID` makes the server report that file's
+// thumbnail as empty. `withNewFile` adds new.jpg (102) to Vacation, advancing
+// the collection's updationTime as the server does, and `refreshError` makes
+// listing collections fail with that message.
+const fakeClient = (
+    opts: {
+        failID?: number;
+        emptyThumbID?: number;
+        withNewFile?: boolean;
+        refreshError?: string;
+    } = {},
+) => {
+    const collections = opts.withNewFile
+        ? [{ ...COLLECTIONS[0], updationTime: 2 }, COLLECTIONS[1]]
+        : COLLECTIONS;
+    const files = opts.withNewFile
+        ? {
+              ...FILES,
+              1: [...FILES[1], { ...file(102, 1, "new.jpg"), updationTime: 2 }],
+          }
+        : FILES;
+    const source: ContentSource = {
+        original: async ({ file: f, destination }) => {
+            if (f.id === opts.failID) throw new Error("HTTP 500 from server");
+            writeFileSync(destination, Buffer.alloc(7, f.id & 0xff));
+            return { bytesWritten: 7 };
+        },
+        thumbnail: async ({ file: f, destination }) => {
+            writeFileSync(destination, Buffer.alloc(3, f.id & 0xff));
+            return { bytesWritten: 3 };
+        },
+    };
+    const fake = {
+        whoami: () => ({ email: "cli@example.com", userID: USER_ID }),
+        collectionsSince: async () => {
+            if (opts.refreshError) throw new Error(opts.refreshError);
+            return { collections, deleted: [], cursor: 1 };
+        },
+        filesSince: async (args: { collectionID: number }) => ({
+            files: files[args.collectionID] ?? [],
+            deleted: [],
+            cursor: 1,
+        }),
+        contentSource: () => source,
+        getApiClient: () => ({
+            // The ML data request of `backup-metadata`: no file has any.
+            postJSON: async () => ({ data: [] }),
+            getThumbnailStream: async (fileID: number) =>
+                new ReadableStream<Uint8Array>({
+                    start(controller) {
+                        if (fileID !== opts.emptyThumbID) {
+                            controller.enqueue(new Uint8Array(3));
+                        }
+                        controller.close();
+                    },
+                }),
+        }),
+    };
+    // The commands only call the methods above.
+    return fake as unknown as Client;
+};
+
+// Collects everything written to it.
+class Output {
+    text = "";
+    write(text: string): void {
+        this.text += text;
+    }
+}
+
+let root: string;
+let stdout: Output;
+let stderr: Output;
+
+const context = (client: Client | null = fakeClient()): CliContext => ({
+    stdout,
+    stderr,
+    sessionDir: join(root, "session"),
+    cacheDir: join(root, "cache"),
+    loadSession: () => client,
+    login: async () => {
+        throw new Error("login not expected");
+    },
+    prompt: async () => {
+        throw new Error("prompt not expected");
+    },
+    promptSecret: async () => {
+        throw new Error("prompt not expected");
+    },
+});
+
+beforeAll(async () => {
+    await init();
+});
+
+beforeEach(() => {
+    root = mkdtempSync(join(tmpdir(), "quak-cli-test-"));
+    stdout = new Output();
+    stderr = new Output();
+});
+
+afterEach(() => {
+    rmSync(root, { recursive: true, force: true });
+});
+
+describe("session file", () => {
+    const snapshot: ClientSnapshot = {
+        email: "cli@example.com",
+        userID: USER_ID,
+        token: "token",
+        masterKey: "a",
+        secretKey: "b",
+        publicKey: "c",
+    };
+
+    it("is written with mode 0600 in a directory with mode 0700", () => {
+        const dir = join(root, "new", "session");
+        saveSession(dir, snapshot);
+        expect(statSync(dir).mode & 0o777).toBe(0o700);
+        const path = join(dir, "session.json");
+        expect(statSync(path).mode & 0o777).toBe(0o600);
+        expect(JSON.parse(readFileSync(path, "utf-8"))).toEqual(snapshot);
+    });
+
+    it("a missing session exits 1 with 'Not logged in'", async () => {
+        const ctx = { ...context(), loadSession };
+        expect(await whoamiCommand(ctx)).toBe(1);
+        expect(stderr.text).toBe(
+            `Not logged in. Run "quak login" first.\n` +
+                `Session file: ${join(ctx.sessionDir, "session.json")}\n`,
+        );
+        expect(stdout.text).toBe("");
+    });
+
+    it("a corrupt session exits 1 and says it is corrupt", async () => {
+        const ctx = { ...context(), loadSession };
+        saveSession(ctx.sessionDir, snapshot);
+        expect(await collectionsCommand(ctx, {})).toBe(1);
+        expect(stderr.text).toContain("is corrupt");
+        expect(stderr.text).toContain(
+            `Run "quak logout" and then "quak login" to replace it.\n`,
+        );
+        expect(stdout.text).toBe("");
+    });
+});
+
+// The login function is a fake that hands back a client whose snapshot is
+// `snapshot`; each prompt is recorded and answered with "123456".
+describe("login", () => {
+    const snapshot: ClientSnapshot = {
+        email: "cli@example.com",
+        userID: USER_ID,
+        token: "token",
+        masterKey: "a",
+        secretKey: "b",
+        publicKey: "c",
+    };
+
+    const loggedIn = {
+        whoami: () => ({ email: "cli@example.com", userID: USER_ID }),
+        toJSON: () => snapshot,
+    } as unknown as Client;
+
+    let prompts: string[];
+
+    const loginContext = (
+        login: (opts: LoginOptions) => Promise<Client>,
+    ): CliContext => ({
+        ...context(),
+        login,
+        prompt: async (message) => {
+            prompts.push(message);
+            return "123456";
+        },
+        promptSecret: async (message) => {
+            prompts.push(message);
+            return "123456";
+        },
+    });
+
+    beforeEach(() => {
+        prompts = [];
+        vi.stubEnv("QUAK_EMAIL", "cli@example.com");
+        vi.stubEnv("QUAK_PASSWORD", "hunter2");
+    });
+
+    afterEach(() => {
+        vi.unstubAllEnvs();
+    });
+
+    it("takes the email and password from the environment without a prompt", async () => {
+        const calls: LoginOptions[] = [];
+        const ctx = loginContext(async (opts) => {
+            calls.push(opts);
+            return loggedIn;
+        });
+        expect(await loginCommand(ctx)).toBe(0);
+
+        expect(prompts).toEqual([]);
+        expect(calls).toHaveLength(1);
+        expect(calls[0]!.email).toBe("cli@example.com");
+        expect(calls[0]!.password).toBe("hunter2");
+        const path = join(ctx.sessionDir, "session.json");
+        expect(stderr.text).toBe(
+            "Authenticating...\n" +
+                `Logged in as cli@example.com (user ${USER_ID})\n` +
+                `Session saved to ${path}\n`,
+        );
+    });
+
+    it("saves the session with mode 0600 in a directory with mode 0700", async () => {
+        const ctx = loginContext(async () => loggedIn);
+        expect(await loginCommand(ctx)).toBe(0);
+
+        expect(statSync(ctx.sessionDir).mode & 0o777).toBe(0o700);
+        const path = join(ctx.sessionDir, "session.json");
+        expect(statSync(path).mode & 0o777).toBe(0o600);
+        expect(JSON.parse(readFileSync(path, "utf-8"))).toEqual(snapshot);
+    });
+
+    it("asks for the TOTP code when the account needs one", async () => {
+        let code: string | undefined;
+        const ctx = loginContext(async (opts) => {
+            code = await opts.totp!();
+            return loggedIn;
+        });
+        expect(await loginCommand(ctx)).toBe(0);
+
+        expect(prompts).toEqual(["TOTP code: "]);
+        expect(code).toBe("123456");
+    });
+
+    it("a failed login exits 1, says why and writes no session", async () => {
+        const ctx = loginContext(async () => {
+            throw new Error("HTTP 401 from server");
+        });
+        expect(await loginCommand(ctx)).toBe(1);
+
+        expect(stderr.text).toBe(
+            "Authenticating...\nLogin failed: HTTP 401 from server\n",
+        );
+        expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(false);
+    });
+});
+
+// These use a real client read from the session file, over a fake API that
+// records each request and answers with `status`.
+describe("logout", () => {
+    const snapshot: ClientSnapshot = {
+        email: "cli@example.com",
+        userID: USER_ID,
+        token: "saved-token",
+        masterKey: toBase64(new Uint8Array(32)),
+        secretKey: toBase64(new Uint8Array(32)),
+        publicKey: toBase64(new Uint8Array(32)),
+    };
+
+    const requests: Request[] = [];
+
+    const logoutContext = (status: number): CliContext => ({
+        ...context(),
+        loadSession: (path) =>
+            loadSession(path, {
+                fetch: async (url, init) => {
+                    requests.push(new Request(url, init));
+                    return new Response(JSON.stringify({}), {
+                        status,
+                        headers: { "content-type": "application/json" },
+                    });
+                },
+            }),
+    });
+
+    beforeEach(() => {
+        requests.length = 0;
+    });
+
+    it("ends the session on the server, then deletes the file", async () => {
+        const ctx = logoutContext(200);
+        saveSession(ctx.sessionDir, snapshot);
+        expect(await logoutCommand(ctx)).toBe(0);
+
+        expect(requests).toHaveLength(1);
+        expect(requests[0]!.method).toBe("POST");
+        expect(new URL(requests[0]!.url).pathname).toBe("/users/logout");
+        expect(requests[0]!.headers.get("X-Auth-Token")).toBe("saved-token");
+        expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(false);
+        expect(stderr.text).toBe(
+            "Session ended on the server.\n" +
+                "Session deleted.\n" +
+                `Cache directory ${ctx.cacheDir} still holds decrypted data; delete it to remove that data.\n`,
+        );
+    });
+
+    it("still deletes the file when the server call fails, and says so", async () => {
+        const ctx = logoutContext(500);
+        saveSession(ctx.sessionDir, snapshot);
+        expect(await logoutCommand(ctx)).toBe(1);
+
+        expect(requests).toHaveLength(1);
+        expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(false);
+        expect(stderr.text).toBe(
+            "Could not end the session on the server: HTTP 500\n" +
+                "Session deleted.\n" +
+                `Cache directory ${ctx.cacheDir} still holds decrypted data; delete it to remove that data.\n`,
+        );
+    });
+
+    it("names the account's default cache directory without --cache-dir", async () => {
+        const ctx = { ...logoutContext(200), cacheDir: undefined };
+        saveSession(ctx.sessionDir, snapshot);
+        expect(await logoutCommand(ctx)).toBe(0);
+        expect(stderr.text).toContain(
+            `Cache directory ${defaultCacheDirectory(USER_ID)} still holds decrypted data`,
+        );
+    });
+
+    it("without a session says so, calls nothing and exits 0", async () => {
+        expect(await logoutCommand(logoutContext(200))).toBe(0);
+        expect(requests).toHaveLength(0);
+        expect(stderr.text).toBe("No session found.\n");
+    });
+});
+
+describe("whoami", () => {
+    it("prints the account as one line of JSON", async () => {
+        expect(await whoamiCommand(context())).toBe(0);
+        expect(stdout.text).toBe(
+            `{"email":"cli@example.com","userID":${USER_ID}}\n`,
+        );
+    });
+});
+
+describe("collections", () => {
+    it("prints one tab-separated line per album", async () => {
+        expect(await collectionsCommand(context(), {})).toBe(0);
+        expect(stdout.text).toBe(
+            "1\talbum\tVacation\n" + "2\talbum\tWork (shared)\n",
+        );
+    });
+
+    it("prints a JSON array with --json", async () => {
+        expect(await collectionsCommand(context(), { json: true })).toBe(0);
+        expect(JSON.parse(stdout.text)).toEqual([
+            {
+                id: 1,
+                name: "Vacation",
+                type: "album",
+                ownerID: USER_ID,
+                isShared: false,
+                updationTime: 1,
+            },
+            {
+                id: 2,
+                name: "Work",
+                type: "album",
+                ownerID: USER_ID,
+                isShared: true,
+                updationTime: 1,
+            },
+        ]);
+    });
+});
+
+describe("files", () => {
+    it("prints one tab-separated line per file", async () => {
+        expect(await filesCommand(context(), { collection: "1" })).toBe(0);
+        expect(stdout.text).toBe(
+            "100\timage\tbeach.jpg\n" + "101\timage\tsunset.jpg\n",
+        );
+    });
+
+    it("prints a JSON array with --json", async () => {
+        const code = await filesCommand(context(), {
+            collection: "2",
+            json: true,
+        });
+        expect(code).toBe(0);
+        expect(JSON.parse(stdout.text)).toEqual([
+            {
+                id: 200,
+                title: "diagram.png",
+                fileType: "image",
+                creationTime: 1000,
+                collectionID: 2,
+            },
+        ]);
+    });
+
+    it("exits 1 for an unknown collection", async () => {
+        expect(await filesCommand(context(), { collection: "9" })).toBe(1);
+        expect(stderr.text).toBe("Collection 9 not found\n");
+    });
+
+    it("exits 1 for a collection ID that is not a number", async () => {
+        expect(await filesCommand(context(), { collection: "abc" })).toBe(1);
+        expect(stderr.text).toBe("Invalid collection ID\n");
+    });
+});
+
+describe("get and get-thumb", () => {
+    it("get finds a file in any album without --collection", async () => {
+        const out = join(root, "diagram.png");
+        expect(await getCommand(context(), "200", { out })).toBe(0);
+        expect(readFileSync(out)).toEqual(Buffer.alloc(7, 200));
+        expect(stderr.text).toBe(`7 bytes -> ${out}\n`);
+    });
+
+    it("get-thumb finds a file in any album without --collection", async () => {
+        const out = join(root, "thumb.jpg");
+        expect(await getThumbCommand(context(), "200", { out })).toBe(0);
+        expect(readFileSync(out)).toEqual(Buffer.alloc(3, 200));
+        expect(stderr.text).toBe(`3 bytes -> ${out}\n`);
+    });
+
+    it("get exits 1 when no album has the file", async () => {
+        const out = join(root, "x");
+        expect(await getCommand(context(), "999", { out })).toBe(1);
+        expect(stderr.text).toBe("File 999 not found\n");
+        expect(existsSync(out)).toBe(false);
+    });
+
+    it("get-thumb exits 1 when no album has the file", async () => {
+        const out = join(root, "x");
+        expect(await getThumbCommand(context(), "999", { out })).toBe(1);
+        expect(stderr.text).toBe("File 999 not found\n");
+        expect(existsSync(out)).toBe(false);
+    });
+
+    it("both exit 1 for a file ID that is not a number", async () => {
+        expect(await getCommand(context(), "abc", {})).toBe(1);
+        expect(await getThumbCommand(context(), "abc", {})).toBe(1);
+        expect(stderr.text).toBe("Invalid file ID\nInvalid file ID\n");
+    });
+});
+
+// A live photo, which Ente stores as one ZIP, is written as its image and its
+// video, which a photo viewer can open. The account here is Vacation holding
+// one live photo, 300, downloaded through the real download layer
+// (test/live-photo.ts).
+describe("a live photo", () => {
+    const livePhotoClient = async (image = IMAGE): Promise<Client> => {
+        const { file: live, body } = await asLivePhoto(
+            file(300, 1, "IMG_0300.HEIC"),
+            livePhotoZip({ "image.heic": image, "video.mov": VIDEO }),
+            livePhotoHash(image, VIDEO),
+        );
+        const fake = {
+            whoami: () => ({ email: "cli@example.com", userID: USER_ID }),
+            collectionsSince: async () => ({
+                collections: [collection(1, "Vacation")],
+                deleted: [],
+                cursor: 1,
+            }),
+            filesSince: async () => ({ files: [live], deleted: [], cursor: 1 }),
+            contentSource: () => cdnSource(new Map([[300, body]])),
+            // The ML data request of `backup-metadata`: no file has any.
+            getApiClient: () => ({ postJSON: async () => ({ data: [] }) }),
+        };
+        return fake as unknown as Client;
+    };
+
+    it("get writes its image and video, named after the title with their own extensions", async () => {
+        const ctx = context(await livePhotoClient());
+        const dir = join(root, "cwd");
+        mkdirSync(dir);
+        const previous = process.cwd();
+        process.chdir(dir);
+        try {
+            expect(await getCommand(ctx, "300", {})).toBe(0);
+        } finally {
+            process.chdir(previous);
+        }
+
+        expect(readdirSync(dir).sort()).toEqual([
+            "IMG_0300.heic",
+            "IMG_0300.mov",
+        ]);
+        expect(readFileSync(join(dir, "IMG_0300.heic"))).toEqual(
+            Buffer.from(IMAGE),
+        );
+        expect(readFileSync(join(dir, "IMG_0300.mov"))).toEqual(
+            Buffer.from(VIDEO),
+        );
+        expect(stderr.text).toBe(
+            `${IMAGE.length} bytes -> IMG_0300.heic\n` +
+                `${VIDEO.length} bytes -> IMG_0300.mov\n`,
+        );
+    });
+
+    it("get --out writes the image there and the video beside it", async () => {
+        const out = join(root, "photo.jpg");
+        const video = join(root, "photo.mov");
+
+        expect(
+            await getCommand(context(await livePhotoClient()), "300", { out }),
+        ).toBe(0);
+
+        expect(readFileSync(out)).toEqual(Buffer.from(IMAGE));
+        expect(readFileSync(video)).toEqual(Buffer.from(VIDEO));
+        expect(stderr.text).toBe(
+            `${IMAGE.length} bytes -> ${out}\n${VIDEO.length} bytes -> ${video}\n`,
+        );
+    });
+
+    it("get exits 1 and writes nothing when --out has the video's extension", async () => {
+        const out = join(root, "photo.MOV");
+
+        expect(
+            await getCommand(context(await livePhotoClient()), "300", { out }),
+        ).toBe(1);
+
+        expect(existsSync(out)).toBe(false);
+        expect(existsSync(join(root, "photo.mov"))).toBe(false);
+        expect(stderr.text).toBe(
+            `File 300 is a live photo, and its video would also be written to ${out}\n`,
+        );
+    });
+
+    it("backup-metadata --exif reads its image", async () => {
+        // A 4x4 JPEG, whose size can only come from reading the image; the
+        // ZIP and the video are not JPEGs.
+        const jpeg = jpegJs.encode(
+            { data: new Uint8Array(4 * 4 * 4), width: 4, height: 4 },
+            50,
+        ).data;
+        const dir = join(root, "dump");
+
+        expect(
+            await backupMetadataCommand(
+                context(await livePhotoClient(new Uint8Array(jpeg))),
+                dir,
+                { exif: true },
+            ),
+        ).toBe(0);
+
+        const record = JSON.parse(
+            readFileSync(
+                join(dir, "collections", "1-Vacation", "300.json"),
+                "utf-8",
+            ),
+        );
+        expect(record.imageMetadata).toMatchObject({
+            format: "jpeg",
+            width: 4,
+            height: 4,
+        });
+    });
+});
+
+describe("backup", () => {
+    it("exits 0 and prints a summary when every file is saved", async () => {
+        const dir = join(root, "backup");
+        expect(await backupCommand(context(), dir, {})).toBe(0);
+        expect(stderr.text).toContain(
+            "\n--- Backup complete ---\n" +
+                "  Total files: 3\n" +
+                "  Downloaded:  3\n" +
+                "  Skipped:     0\n" +
+                "  Failed:      0\n",
+        );
+        expect(stdout.text).toBe("");
+    });
+
+    // The backup opens its library with the precache off: it fetches the
+    // originals it needs into the backup, and must not also fetch every
+    // thumbnail in the account, or keep originals, in the per-user cache.
+    it("leaves nothing in the cache's originals and thumbnails", async () => {
+        const dir = join(root, "backup");
+        expect(await backupCommand(context(), dir, {})).toBe(0);
+        expect(readdirSync(join(root, "cache", "thumbnails"))).toEqual([]);
+        expect(readdirSync(join(root, "cache", "originals"))).toEqual([]);
+    });
+
+    it("exits 1 and lists the file when one download fails", async () => {
+        const ctx = context(fakeClient({ failID: 101 }));
+        expect(await backupCommand(ctx, join(root, "backup"), {})).toBe(1);
+        expect(stderr.text).toContain("  Failed:      1\n");
+        expect(stderr.text).toContain(
+            "\nFailed files:\n" +
+                "  [Vacation] sunset.jpg (id 101): HTTP 500 from server\n",
+        );
+    });
+
+    it("prints the result as JSON with --json, still exiting 1 on a failure", async () => {
+        const ctx = context(fakeClient({ failID: 101 }));
+        const code = await backupCommand(ctx, join(root, "backup"), {
+            json: true,
+        });
+        expect(code).toBe(1);
+        const result = JSON.parse(stdout.text);
+        expect(result).toMatchObject({
+            totalFiles: 3,
+            downloaded: 2,
+            skipped: 0,
+            failed: 1,
+        });
+        expect(result.errors[0].fileID).toBe(101);
+        expect(stderr.text).toBe("Starting backup...\n");
+    });
+
+    it("exits 1 with the error on one line when the refresh fails", async () => {
+        const client = {
+            ...fakeClient(),
+            collectionsSince: async () => {
+                throw new Error("HTTP 401 from server");
+            },
+        } as unknown as Client;
+        const dir = join(root, "backup");
+        // Through `run`, as `bin/quak.ts` does, which prints a thrown error.
+        const runStderr = new PassThrough();
+        let runText = "";
+        runStderr.on("data", (chunk: Buffer) => {
+            runText += chunk.toString();
+        });
+        const code = await new Promise<number>((resolve) => {
+            void run(
+                backupCommand(context(client), dir, {}),
+                new PassThrough(),
+                runStderr,
+                resolve,
+            );
+        });
+        expect(code).toBe(1);
+        expect(runText).toBe("quak: HTTP 401 from server\n");
+        expect(stderr.text).toBe("Starting backup...\nRefreshing library...\n");
+        expect(existsSync(join(dir, "originals"))).toBe(false);
+    });
+});
+
+describe("helper list-missing-thumbnails", () => {
+    it("prints one line per file with an empty thumbnail", async () => {
+        const ctx = context(fakeClient({ emptyThumbID: 200 }));
+        expect(await listMissingThumbnailsCommand(ctx, {})).toBe(0);
+        expect(stdout.text).toBe(
+            "200\tdiagram.png\tWork\tempty thumbnail (0 bytes)\n",
+        );
+        expect(stderr.text).toContain("\n1 file(s) with missing thumbnails:\n");
+    });
+
+    it("says so when nothing is missing", async () => {
+        expect(await listMissingThumbnailsCommand(context(), {})).toBe(0);
+        expect(stdout.text).toBe("");
+        expect(stderr.text).toContain("No missing thumbnails found.\n");
+    });
+
+    it("prints a JSON array with --json and no progress", async () => {
+        const ctx = context(fakeClient({ emptyThumbID: 200 }));
+        expect(await listMissingThumbnailsCommand(ctx, { json: true })).toBe(0);
+        expect(JSON.parse(stdout.text)).toEqual([
+            {
+                fileID: 200,
+                title: "diagram.png",
+                collection: "Work",
+                reason: "empty thumbnail (0 bytes)",
+            },
+        ]);
+        expect(stderr.text).toBe("");
+    });
+});
+
+describe("backup-metadata --exif", () => {
+    // Runs the command and returns what it printed to stderr.
+    const backupMetadata = async (opts: { exif?: boolean; all?: boolean }) => {
+        expect(
+            await backupMetadataCommand(context(), join(root, "dump"), opts),
+        ).toBe(0);
+        return stderr.text;
+    };
+
+    it("--exif extracts EXIF", async () => {
+        expect(await backupMetadata({ exif: true })).toContain(
+            "[beach.jpg] Extracting EXIF...\n",
+        );
+    });
+
+    it("--all extracts EXIF", async () => {
+        expect(await backupMetadata({ all: true })).toContain(
+            "[beach.jpg] Extracting EXIF...\n",
+        );
+    });
+
+    it("without either flag extracts no EXIF", async () => {
+        expect(await backupMetadata({})).not.toContain("Extracting EXIF");
+    });
+});
+
+// Each test first runs `collections` so the cache holds the account as it was,
+// then changes the server under it.
+describe("backup-metadata and the thumbnail helpers refresh first", () => {
+    beforeEach(async () => {
+        expect(await collectionsCommand(context(), {})).toBe(0);
+        stdout.text = "";
+        stderr.text = "";
+    });
+
+    it("backup-metadata writes a file added since the cache was written", async () => {
+        const ctx = context(fakeClient({ withNewFile: true }));
+        const dir = join(root, "dump");
+        expect(await backupMetadataCommand(ctx, dir, {})).toBe(0);
+        expect(
+            existsSync(join(dir, "collections", "1-Vacation", "102.json")),
+        ).toBe(true);
+    });
+
+    it("list-missing-thumbnails checks a file added since the cache was written", async () => {
+        const ctx = context(
+            fakeClient({ withNewFile: true, emptyThumbID: 102 }),
+        );
+        expect(await listMissingThumbnailsCommand(ctx, {})).toBe(0);
+        expect(stdout.text).toBe(
+            "102\tnew.jpg\tVacation\tempty thumbnail (0 bytes)\n",
+        );
+    });
+
+    it("fix-missing-thumbnails finds a file added since the cache was written", async () => {
+        const ctx = context(fakeClient({ withNewFile: true }));
+        expect(
+            await fixMissingThumbnailsCommand(ctx, {
+                file: ["102"],
+                json: true,
+            }),
+        ).toBe(0);
+        // Found, then skipped because the server records no thumbnail size
+        // for it; a file missing from the cache would fail as not found.
+        expect(JSON.parse(stdout.text)).toMatchObject([
+            { fileID: 102, title: "new.jpg", status: "skipped" },
+        ]);
+    });
+
+    // `run` in `cli-run.ts` prints a thrown error as one line and exits 1.
+    it("all three throw when the refresh fails", async () => {
+        const ctx = context(
+            fakeClient({ refreshError: "HTTP 503 from server" }),
+        );
+        const dir = join(root, "dump");
+        await expect(backupMetadataCommand(ctx, dir, {})).rejects.toThrow(
+            "HTTP 503 from server",
+        );
+        expect(existsSync(dir)).toBe(false);
+        await expect(listMissingThumbnailsCommand(ctx, {})).rejects.toThrow(
+            "HTTP 503 from server",
+        );
+        await expect(
+            fixMissingThumbnailsCommand(ctx, { file: ["100"] }),
+        ).rejects.toThrow("HTTP 503 from server");
+        expect(stdout.text).toBe("");
+    });
+});

test/cli/metadata-backup.test.ts

@@ -38,7 +38,7 @@ import { join } from "node:path";
 import { tmpdir } from "node:os";
 import sodium from "libsodium-wrappers-sumo";
 import { SRP, SrpServer } from "fast-srp-hap";
-import { beforeAll, afterAll, describe, expect, it } from "vitest";
+import { beforeAll, afterAll, describe, expect, it, vi } from "vitest";
 import {
     init,
     toBase64,
@@ -53,8 +53,16 @@ import {
     runMetadataBackup,
     type MetadataBackupOptions,
 } from "../../src/metadata-backup.js";
+import { backupMetadataCommand } from "../../src/cli-commands.js";
 import type { KeyAttributes } from "../../src/auth/types.js";
 
+// One file per ML data request, so the two files of the mock account are
+// fetched in two requests and one of them can fail on its own.
+vi.mock("../../src/mldata-fetch.js", async (importOriginal) => ({
+    ...(await importOriginal<typeof import("../../src/mldata-fetch.js")>()),
+    MLDATA_BATCH_SIZE: 1,
+}));
+
 const TEST_EMAIL = "metabackup@example.com";
 const TEST_PASSWORD = "metapass";
 const TEST_OPS = 2;
@@ -347,7 +355,8 @@ const buildMetaMock = async (): Promise<MetaMockState> => {
     };
 };
 
-const buildMetaFetch = (m: MetaMockState) => {
+// `failMLDataFor`: answer 500 to every ML data request that asks for this file.
+const buildMetaFetch = (m: MetaMockState, failMLDataFor?: number) => {
     let srpServer: SrpServer;
     return (async (
         input: RequestInfo | URL,
@@ -403,6 +412,8 @@ const buildMetaFetch = (m: MetaMockState) => {
         }
         if (path === "/files/data/fetch") {
             const body = JSON.parse(init?.body as string);
+            if ((body.fileIDs as number[]).includes(failMLDataFor!))
+                return new Response("server error", { status: 500 });
             const data = (body.fileIDs as number[])
                 .filter((id: number) => m.encryptedMLData[id])
                 .map((id: number) => ({
@@ -621,5 +632,78 @@ describe("quak backup-metadata", () => {
         expect(fileMeta.imageMetadata.format).toBe("jpeg");
         expect(fileMeta.imageMetadata.width).toBe(100);
         expect(fileMeta.imageMetadata.height).toBe(80);
+        expect(fileMeta.imageMetadataError).toBeUndefined();
+
+        // File 200 has no original on the mock server, so extraction fails
+        // and the reason is recorded instead of the field being left out.
+        const workDir = collDirs.find((d) => d.includes("Work"))!;
+        const failedMeta = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", workDir, "200.json"),
+                "utf-8",
+            ),
+        );
+        expect(failedMeta.imageMetadata).toBeUndefined();
+        expect(failedMeta.imageMetadataError).toEqual(expect.any(String));
+    });
+});
+
+describe("quak backup-metadata when an ML data request fails", () => {
+    // Run the CLI command against the mock and return its exit code, stderr
+    // and output directory.
+    const runCommand = async (failMLDataFor?: number) => {
+        const client = await Client.login({
+            email: TEST_EMAIL,
+            password: TEST_PASSWORD,
+            apiOptions: {
+                fetch: buildMetaFetch(mock, failMLDataFor),
+                retry: { sleep: async () => {} },
+            },
+        });
+        const outDir = mkdtempSync(join(testDir, "ml-fail-"));
+        let stderr = "";
+        const code = await backupMetadataCommand(
+            {
+                stdout: { write: () => true },
+                stderr: { write: (text: string) => (stderr += text) },
+                sessionDir: testDir,
+                cacheDir: mkdtempSync(join(testDir, "cache-")),
+                loadSession: () => client,
+            },
+            outDir,
+            {},
+        );
+        return { code, stderr, outDir };
+    };
+
+    it("writes every file, marks the failed batch's files, and exits 1", async () => {
+        const { code, stderr, outDir } = await runCommand(200);
+
+        expect(code).toBe(1);
+        expect(stderr).toContain("ML data request for 1 file(s) failed");
+
+        const ok = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", "10-Vacation", "100.json"),
+                "utf-8",
+            ),
+        );
+        expect(ok.mlData.clip.embedding).toEqual([0.5, 0.6, 0.7]);
+        expect(ok.mlDataError).toBeUndefined();
+
+        const failed = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", "20-__Work", "200.json"),
+                "utf-8",
+            ),
+        );
+        expect(failed.metadata.title).toBe("diagram.png");
+        expect(failed.mlData).toBeUndefined();
+        expect(failed.mlDataError).toContain("500");
+    });
+
+    it("exits 0 when every ML data request succeeds", async () => {
+        const { code } = await runCommand();
+        expect(code).toBe(0);
     });
 });

test/cli/metadata-exif.test.ts

@@ -0,0 +1,136 @@
+/**
+ * Tests for the JPEG EXIF scan behind `quak backup-metadata --exif`.
+ *
+ * The originals come from users' libraries, so a truncated or corrupt JPEG
+ * must neither hang the scan nor throw out of it, and a malformed file must be
+ * told apart from one that simply has no EXIF: the record carries the reason in
+ * `exifError`. Each input below is a short hand-built byte array.
+ */
+
+import { describe, expect, it } from "vitest";
+import {
+    extractExifFromJpeg,
+    extractImageMetadata,
+} from "../../src/metadata-backup.js";
+
+const SOI = [0xff, 0xd8]; // start of image
+const SOS = [0xff, 0xda, 0x00, 0x02]; // start of scan, where the scan stops
+const EXIF_HEADER = [0x45, 0x78, 0x69, 0x66, 0x00, 0x00]; // "Exif\0\0"
+
+// A big-endian TIFF block with one IFD entry: Orientation (0x0112), SHORT, 6.
+const TIFF_ORIENTATION_6 = [
+    0x4d, 0x4d, 0x00, 0x2a, 0x00, 0x00, 0x00, 0x08, 0x00, 0x01, 0x01, 0x12,
+    0x00, 0x03, 0x00, 0x00, 0x00, 0x01, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00,
+];
+
+// An APP1 segment whose length field matches its data.
+const app1 = (data: number[]): number[] => {
+    const len = data.length + 2;
+    return [0xff, 0xe1, len >> 8, len & 0xff, ...data];
+};
+
+const bytes = (...parts: number[][]): Uint8Array =>
+    new Uint8Array(parts.flat());
+
+describe("extractExifFromJpeg", () => {
+    it("returns the EXIF segment of a valid JPEG", () => {
+        const data = [...EXIF_HEADER, ...TIFF_ORIENTATION_6];
+        const scan = extractExifFromJpeg(bytes(SOI, app1(data), SOS));
+        expect(scan.error).toBeUndefined();
+        expect([...scan.exif!]).toEqual(data);
+    });
+
+    it("returns nothing for a file that is not a JPEG", () => {
+        const png = bytes([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]);
+        expect(extractExifFromJpeg(png)).toEqual({});
+    });
+
+    it("returns nothing for a JPEG without EXIF", () => {
+        const app0 = [0xff, 0xe0, 0x00, 0x04, 0x00, 0x00];
+        expect(extractExifFromJpeg(bytes(SOI, app0, SOS))).toEqual({});
+    });
+
+    it("ignores an APP1 segment too short to hold the Exif header", () => {
+        // A length under 8 cannot hold the six-byte "Exif\0\0" header, so the
+        // segment is not EXIF. This one has length 7 and holds only "Exif\0",
+        // which the old code, lacking the length check, returned as EXIF.
+        const short = app1(EXIF_HEADER.slice(0, 5));
+        expect(extractExifFromJpeg(bytes(SOI, short, SOS))).toEqual({});
+    });
+
+    it("accepts an APP1 segment of length 8 holding just the Exif header", () => {
+        const scan = extractExifFromJpeg(bytes(SOI, app1(EXIF_HEADER), SOS));
+        expect(scan.error).toBeUndefined();
+        expect([...scan.exif!]).toEqual(EXIF_HEADER);
+    });
+
+    it("reports a JPEG truncated inside a segment header", () => {
+        const scan = extractExifFromJpeg(bytes(SOI, [0xff, 0xe1, 0x00]));
+        expect(scan.exif).toBeUndefined();
+        expect(scan.error).toMatch(/truncated segment length/);
+    });
+
+    it("reports a JPEG that ends before the image data", () => {
+        const app0 = [0xff, 0xe0, 0x00, 0x04, 0x00, 0x00];
+        const scan = extractExifFromJpeg(bytes(SOI, app0));
+        expect(scan.error).toMatch(/ends before the image data/);
+    });
+
+    it("stops on a zero-length segment instead of looping", () => {
+        // A length of 0 would otherwise step the scan by 2 bytes at a time
+        // through the rest of the file, reading garbage as markers.
+        const zero = [0xff, 0xe0, 0x00, 0x00];
+        const scan = extractExifFromJpeg(
+            bytes(SOI, zero, zero, zero, zero, SOS),
+        );
+        expect(scan.error).toMatch(/segment length 0 at byte 2 is too small/);
+    });
+
+    it("stops on a segment length of 1", () => {
+        const scan = extractExifFromJpeg(
+            bytes(SOI, [0xff, 0xe0, 0x00, 0x01], SOS),
+        );
+        expect(scan.error).toMatch(/segment length 1 at byte 2 is too small/);
+    });
+
+    it("reports a segment length that runs past the end of the file", () => {
+        // APP1 claims 0x4000 bytes but only the "Exif\0\0" header follows.
+        const scan = extractExifFromJpeg(
+            bytes(SOI, [0xff, 0xe1, 0x40, 0x00], EXIF_HEADER),
+        );
+        expect(scan.exif).toBeUndefined();
+        expect(scan.error).toMatch(/runs past the end of the file/);
+    });
+});
+
+describe("extractImageMetadata", () => {
+    it("parses EXIF from a valid JPEG", () => {
+        const meta = extractImageMetadata(
+            bytes(SOI, app1([...EXIF_HEADER, ...TIFF_ORIENTATION_6]), SOS),
+        );
+        expect(meta?.exifError).toBeUndefined();
+        expect(meta?.exif).toMatchObject({ Image: { Orientation: 6 } });
+    });
+
+    it("returns nothing for a file that is not a JPEG", () => {
+        const text = new TextEncoder().encode("just some text, not an image");
+        expect(extractImageMetadata(text)).toBeUndefined();
+    });
+
+    it("records the reason when the JPEG is malformed", () => {
+        const meta = extractImageMetadata(
+            bytes(SOI, [0xff, 0xe1, 0x40, 0x00], EXIF_HEADER),
+        );
+        expect(meta?.exif).toBeUndefined();
+        expect(meta?.exifError).toMatch(/runs past the end of the file/);
+    });
+
+    it("keeps the raw bytes and the reason when EXIF cannot be parsed", () => {
+        const data = [...EXIF_HEADER, 0x58, 0x58];
+        const meta = extractImageMetadata(bytes(SOI, app1(data), SOS));
+        expect(meta?.exif).toBeUndefined();
+        expect(meta?.exifRaw).toBe(Buffer.from(data).toString("base64"));
+        expect(meta?.exifError).toEqual(expect.any(String));
+    });
+});

test/cli/run.test.ts

@@ -0,0 +1,58 @@
+/**
+ * Tests for `run` in `src/cli-run.ts`, which every CLI command goes through.
+ */
+
+import { PassThrough } from "node:stream";
+import { describe, it, expect } from "vitest";
+
+import { run } from "../../src/cli-run.js";
+
+// A stream whose written text is kept in `text`; writes finish at once, so
+// nothing is left waiting to drain.
+const collector = (): { stream: PassThrough; text: () => string } => {
+    const stream = new PassThrough();
+    const chunks: string[] = [];
+    stream.on("data", (chunk: Buffer) => chunks.push(chunk.toString()));
+    return { stream, text: () => chunks.join("") };
+};
+
+const runToExit = async (
+    command: Promise<number>,
+): Promise<{ code: number; stdout: string; stderr: string }> => {
+    const stdout = collector();
+    const stderr = collector();
+    const code = await new Promise<number>((resolve) => {
+        void run(command, stdout.stream, stderr.stream, resolve);
+    });
+    return { code, stdout: stdout.text(), stderr: stderr.text() };
+};
+
+describe("run", () => {
+    it("exits with the code the command returns", async () => {
+        const result = await runToExit(Promise.resolve(3));
+        expect(result).toEqual({ code: 3, stdout: "", stderr: "" });
+    });
+
+    it("prints a thrown error as one line without a stack trace and exits 1", async () => {
+        const failing = async (): Promise<number> => {
+            throw new Error(
+                "ENOTDIR: not a directory, mkdir '/dev/null/x/originals'",
+            );
+        };
+        const result = await runToExit(failing());
+        expect(result.code).toBe(1);
+        expect(result.stdout).toBe("");
+        expect(result.stderr).toBe(
+            "quak: ENOTDIR: not a directory, mkdir '/dev/null/x/originals'\n",
+        );
+    });
+
+    it("prints a thrown value that is not an Error", async () => {
+        const result = await runToExit(Promise.reject("offline"));
+        expect(result).toEqual({
+            code: 1,
+            stdout: "",
+            stderr: "quak: offline\n",
+        });
+    });
+});

test/client/session.test.ts

@@ -0,0 +1,197 @@
+/**
+ * Tests for the client session lifecycle: `toJSON`, `fromJSON`, `logout`, and
+ * the CLI's `loadSession`, which reads the saved session file back into a
+ * client.
+ */
+
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import sodium from "libsodium-wrappers-sumo";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+import { init, toBase64 } from "../../src/crypto/index.js";
+import { Client, type ClientSnapshot } from "../../src/client.js";
+import { loadSession } from "../../src/cli-session.js";
+
+const validSnapshot = (): ClientSnapshot => {
+    const kp = sodium.crypto_box_keypair();
+    return {
+        email: "user@example.com",
+        userID: 42,
+        token: "test-token",
+        masterKey: toBase64(sodium.crypto_secretbox_keygen()),
+        secretKey: toBase64(kp.privateKey),
+        publicKey: toBase64(kp.publicKey),
+    };
+};
+
+// The client's key buffers are private; the tests read them to prove that
+// logout wipes them.
+const keyBuffers = (client: Client): Uint8Array[] => [
+    client["masterKey"],
+    client["secretKey"],
+    client["publicKey"],
+];
+
+beforeAll(async () => {
+    await init();
+});
+
+describe("Client.toJSON", () => {
+    it("round-trips through fromJSON unchanged", () => {
+        const snapshot = validSnapshot();
+        expect(Client.fromJSON(snapshot).toJSON()).toEqual(snapshot);
+    });
+
+    it("throws instead of emitting a snapshot without a token", () => {
+        const client = Client.fromJSON(validSnapshot());
+        client.getApiClient().clearAuthToken();
+        expect(() => client.toJSON()).toThrow(/no auth token/);
+    });
+});
+
+describe("Client.fromJSON", () => {
+    const shortKey = toBase64(new Uint8Array(16));
+
+    it.each([
+        ["email", undefined],
+        ["email", 7],
+        ["email", ""],
+        ["token", undefined],
+        ["token", null],
+        ["token", ""],
+        ["userID", undefined],
+        ["userID", "42"],
+        ["userID", 4.2],
+        ["masterKey", undefined],
+        ["masterKey", 7],
+        ["masterKey", "not base64!"],
+        ["masterKey", shortKey],
+        ["secretKey", undefined],
+        ["secretKey", "not base64!"],
+        ["secretKey", shortKey],
+        ["publicKey", undefined],
+        ["publicKey", "not base64!"],
+        ["publicKey", shortKey],
+    ])("rejects %s = %j, naming the field", (field, value) => {
+        const snapshot: Record<string, unknown> = { ...validSnapshot() };
+        snapshot[field] = value;
+        expect(() => Client.fromJSON(snapshot)).toThrow(
+            new RegExp(`^Invalid session data: ${field} `),
+        );
+    });
+
+    it.each([null, "a string", 42])("rejects a non-object %j", (value) => {
+        expect(() => Client.fromJSON(value)).toThrow(
+            /^Invalid session data: not a JSON object/,
+        );
+    });
+});
+
+describe("Client.logout", () => {
+    it("zeroes the key buffers and clears the token", () => {
+        const client = Client.fromJSON(validSnapshot());
+        const api = client.getApiClient();
+        const keys = keyBuffers(client);
+
+        client.logout();
+
+        for (const key of keys) {
+            expect(key.length).toBe(32);
+            expect(key.every((b) => b === 0)).toBe(true);
+        }
+        expect(api.getAuthToken()).toBeUndefined();
+    });
+
+    it("makes every later operation throw", async () => {
+        const client = Client.fromJSON(validSnapshot());
+        client.logout();
+
+        expect(() => client.whoami()).toThrow(/logged out/);
+        expect(() => client.toJSON()).toThrow(/logged out/);
+        expect(() => client.getApiClient()).toThrow(/logged out/);
+        expect(() => client.contentSource()).toThrow(/logged out/);
+        await expect(client.listCollections()).rejects.toThrow(/logged out/);
+        await expect(client.collectionsSince({ sinceTime: 0 })).rejects.toThrow(
+            /logged out/,
+        );
+        await expect(
+            client.filesSince({
+                collectionID: 1,
+                collectionKey: new Uint8Array(32),
+                sinceTime: 0,
+            }),
+        ).rejects.toThrow(/logged out/);
+        await expect(
+            client.fetchMLData({ fileIDs: [1], fileKeys: new Map() }),
+        ).rejects.toThrow(/logged out/);
+    });
+
+    it("stops a listing in flight from decrypting with the zeroed keys", async () => {
+        // The server answers only after the client has logged out. If the
+        // listing went on to decrypt this row with all-zero keys it would fail
+        // with a decryption error, not the logged-out one.
+        const row = {
+            id: 1,
+            owner: { id: 42 },
+            encryptedKey: toBase64(new Uint8Array(48)),
+            keyDecryptionNonce: toBase64(new Uint8Array(24)),
+            updationTime: 1,
+        };
+        const client: Client = Client.fromJSON(validSnapshot(), {
+            fetch: async () => {
+                client.logout();
+                return new Response(JSON.stringify({ collections: [row] }), {
+                    status: 200,
+                    headers: { "content-type": "application/json" },
+                });
+            },
+        });
+
+        await expect(client.listCollections()).rejects.toThrow(/logged out/);
+    });
+});
+
+describe("loadSession", () => {
+    let dir: string;
+
+    beforeAll(() => {
+        dir = mkdtempSync(join(tmpdir(), "quak-session-test-"));
+    });
+
+    afterAll(() => {
+        rmSync(dir, { recursive: true, force: true });
+    });
+
+    it("returns null when there is no session file", () => {
+        expect(loadSession(join(dir, "missing.json"))).toBeNull();
+    });
+
+    it("restores a client from a valid session file", () => {
+        const path = join(dir, "valid.json");
+        writeFileSync(path, JSON.stringify(validSnapshot()));
+        expect(loadSession(path)!.whoami()).toEqual({
+            email: "user@example.com",
+            userID: 42,
+        });
+    });
+
+    it("says the file is corrupt when it is not JSON", () => {
+        const path = join(dir, "truncated.json");
+        writeFileSync(path, '{"email": "user@exa');
+        expect(() => loadSession(path)).toThrow(
+            `Session file ${path} is corrupt`,
+        );
+    });
+
+    it("says the file is corrupt and names the bad field", () => {
+        const path = join(dir, "bad-key.json");
+        writeFileSync(
+            path,
+            JSON.stringify({ ...validSnapshot(), secretKey: "AAAA" }),
+        );
+        expect(() => loadSession(path)).toThrow(
+            new RegExp(`^Session file ${path} is corrupt: .*secretKey`),
+        );
+    });
+});

test/crypto/hash.test.ts

@@ -0,0 +1,33 @@
+import { beforeAll, describe, expect, it } from "vitest";
+import {
+    chunkHashFinal,
+    chunkHashInit,
+    chunkHashUpdate,
+    init,
+} from "../../src/crypto/index.js";
+
+beforeAll(async () => {
+    await init();
+});
+
+describe("content hash", () => {
+    // RFC 7693 Appendix A: BLAKE2b-512 of "abc".
+    const abc = Buffer.from(
+        "ba80a53f981c4d0d6a2797b69f12f6e94c212f14685ac4b74b12bb6fdbffa2d1" +
+            "7d87c5392aab792dc252d5de4533cc9518d38aa8dbf1925ab92386edd4009923",
+        "hex",
+    ).toString("base64");
+
+    it("is unkeyed BLAKE2b-512 in standard base64", () => {
+        const state = chunkHashInit();
+        chunkHashUpdate(state, new TextEncoder().encode("abc"));
+        expect(chunkHashFinal(state)).toBe(abc);
+    });
+
+    it("gives the same hash when the input arrives in chunks", () => {
+        const state = chunkHashInit();
+        chunkHashUpdate(state, new TextEncoder().encode("a"));
+        chunkHashUpdate(state, new TextEncoder().encode("bc"));
+        expect(chunkHashFinal(state)).toBe(abc);
+    });
+});

test/crypto/kdf.test.ts

@@ -29,10 +29,10 @@ describe("crypto.deriveKEK (Argon2id)", () => {
     });
 
     /**
-     * Cheap parameters used so the test suite stays under the 30-second
-     * budget. The real production parameters Ente uses are larger
-     * (memLimit up to 1 GiB, opsLimit 3-16). The algorithm is the same
-     * regardless of parameters.
+     * Cheap parameters used so the test suite stays under the 90-second
+     * `timeout` in the `test` phase of the `Dockerfile`. The real production
+     * parameters Ente uses are larger (memLimit up to 1 GiB, opsLimit 3-16).
+     * The algorithm is the same regardless of parameters.
      */
     const TEST_OPS = 2;
     const TEST_MEM = 64 * 1024 * 1024; // 64 MiB

test/download/download.test.ts

@@ -48,18 +48,21 @@
  */
 
 import {
+    chmodSync,
     existsSync,
     mkdirSync,
     readdirSync,
     readFileSync,
     rmSync,
     mkdtempSync,
+    statSync,
     writeFileSync,
 } from "node:fs";
 import { dirname, join } from "node:path";
 import { tmpdir } from "node:os";
 import { createHash } from "node:crypto";
 import sodium from "libsodium-wrappers-sumo";
+import { zipSync } from "fflate";
 import {
     beforeAll,
     beforeEach,
@@ -79,6 +82,7 @@ import {
     writeAtomic,
 } from "../../src/download/index.js";
 import type { EnteFile, FileMetadata } from "../../src/model/types.js";
+import { IMAGE, livePhotoHash, livePhotoZip, VIDEO } from "../live-photo.js";
 
 // ---------------------------------------------------------------------------
 // Test helpers
@@ -104,6 +108,8 @@ import type { EnteFile, FileMetadata } from "../../src/model/types.js";
 const renameHook = vi.hoisted(() => ({
     calls: [] as { from: string; to: string; sourceExisted: boolean }[],
     failWith: null as Error | null,
+    // When set, only a rename to this path fails.
+    failTo: null as string | null,
 }));
 
 /**
@@ -179,7 +185,10 @@ vi.mock("node:fs/promises", async (importOriginal) => {
                 sourceExisted: sourceExists(from),
             });
             durabilityHook.events.push(`rename:${to}`);
-            if (renameHook.failWith !== null) {
+            if (
+                renameHook.failWith !== null &&
+                (renameHook.failTo === null || renameHook.failTo === to)
+            ) {
                 throw renameHook.failWith;
             }
             await actual.rename(from, to);
@@ -187,9 +196,34 @@ vi.mock("node:fs/promises", async (importOriginal) => {
     };
 });
 
+/**
+ * `chunkHashUpdate` is wrapped to record the length of every piece hashed, so
+ * a test can show that a live photo entry reaches the hash in pieces far
+ * smaller than the entry, rather than decompressed whole first.
+ */
+const hashHook = vi.hoisted(() => ({
+    lengths: [] as number[],
+}));
+
+vi.mock("../../src/crypto/index.js", async (importOriginal) => {
+    const actual =
+        await importOriginal<typeof import("../../src/crypto/index.js")>();
+    return {
+        ...actual,
+        chunkHashUpdate: (
+            ...args: Parameters<typeof actual.chunkHashUpdate>
+        ): void => {
+            hashHook.lengths.push(args[1].length);
+            actual.chunkHashUpdate(...args);
+        },
+    };
+});
+
 beforeEach(() => {
+    hashHook.lengths.length = 0;
     renameHook.calls.length = 0;
     renameHook.failWith = null;
+    renameHook.failTo = null;
     durabilityHook.events.length = 0;
     writeHook.writes.length = 0;
 });
@@ -222,7 +256,8 @@ afterAll(() => {
  * `sodium.randombytes_buf` goes through the wasm wrapper a byte at a time and
  * costs roughly 20 seconds for the 4 MiB chunk below — about two hundred
  * times what it costs to encrypt the same buffer, and on its own enough to
- * push `make test` past the 30-second cap in `script/test`. This loop fills
+ * push `make test` past the 90-second `timeout` in the `test` phase of the
+ * `Dockerfile`. This loop fills
  * 4 MiB in a few milliseconds.
  */
 const patternBytes = (length: number, seed: number): Uint8Array => {
@@ -989,6 +1024,47 @@ describe.each(entryPoints)(
             expect(readFileSync(outPath)).toEqual(Buffer.from(existing));
             expect(readdirSync(dir)).toEqual(["rename-fails.bin"]);
         });
+
+        it("fails without creating anything when the destination directory does not exist", async () => {
+            const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+            const { header, ciphertext } = encryptFileBody(
+                patternBytes(64, 33),
+                key,
+            );
+            const { api, file } = fixtureFor(key, header, ciphertext);
+            const dir = freshDir();
+            const outPath = join(dir, "missing", "never.bin");
+
+            await expect(download(api, file, outPath)).rejects.toMatchObject({
+                code: "ENOENT",
+            });
+
+            // The missing directory is not created on the caller's behalf.
+            expect(readdirSync(dir)).toEqual([]);
+        });
+
+        // Root ignores directory permissions, so this fails when run as root.
+        // The `test` phase of the `Dockerfile` runs as the `node` user.
+        it("fails without creating anything when the destination directory is not writable", async () => {
+            const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+            const { header, ciphertext } = encryptFileBody(
+                patternBytes(64, 34),
+                key,
+            );
+            const { api, file } = fixtureFor(key, header, ciphertext);
+            const dir = freshDir();
+            const outPath = join(dir, "never.bin");
+            chmodSync(dir, 0o500);
+            try {
+                await expect(
+                    download(api, file, outPath),
+                ).rejects.toMatchObject({ code: "EACCES" });
+            } finally {
+                chmodSync(dir, 0o700);
+            }
+
+            expect(readdirSync(dir)).toEqual([]);
+        });
     },
 );
 
@@ -1291,6 +1367,102 @@ describe("download retries: corruption is not retried", () => {
 
         expect(requests()).toBe(1);
     });
+
+    it("cancels the response body when decryption fails", async () => {
+        // A backup run carries on past a failed file, so a body left open on
+        // failure would hold its connection until garbage collection, once
+        // per failed file. This body delivers a corrupt chunk and then stays
+        // open, so only a cancel from the downloader can close it.
+        const corrupted = Uint8Array.from(multiChunk.body);
+        corrupted[10] ^= 0xff;
+        let cancelled = false;
+        const fetch = (async () =>
+            new Response(
+                new ReadableStream<Uint8Array>({
+                    start(controller) {
+                        controller.enqueue(corrupted);
+                    },
+                    cancel() {
+                        cancelled = true;
+                    },
+                }),
+                { status: 200 },
+            )) as typeof globalThis.fetch;
+        const api = new ApiClient({ fetch, retry: { ...noWait, attempts: 1 } });
+        const file = buildMockEnteFile(
+            multiChunkKey,
+            multiChunk.header,
+            multiChunk.header,
+        );
+        const outPath = join(mkdtempSync(join(testDir, "cancel-")), "c.bin");
+
+        await expect(downloadFile(api, file, outPath)).rejects.toThrow(
+            /authentication failed/i,
+        );
+
+        expect(cancelled).toBe(true);
+    });
+
+    it("cancels the response body when the temp file cannot be opened", async () => {
+        // The download fails before a byte of the body is read, so the body
+        // is still open and only a cancel from the downloader can close it.
+        let cancelled = false;
+        const fetch = (async () =>
+            new Response(
+                new ReadableStream<Uint8Array>({
+                    start(controller) {
+                        controller.enqueue(multiChunk.body);
+                    },
+                    cancel() {
+                        cancelled = true;
+                    },
+                }),
+                { status: 200 },
+            )) as typeof globalThis.fetch;
+        const api = new ApiClient({ fetch, retry: { ...noWait, attempts: 1 } });
+        const file = buildMockEnteFile(
+            multiChunkKey,
+            multiChunk.header,
+            multiChunk.header,
+        );
+        const outPath = join(
+            mkdtempSync(join(testDir, "cancel-")),
+            "missing",
+            "c.bin",
+        );
+
+        await expect(downloadFile(api, file, outPath)).rejects.toMatchObject({
+            code: "ENOENT",
+        });
+
+        expect(cancelled).toBe(true);
+    });
+
+    it("cancels the response body when the header is malformed", async () => {
+        // The header is rejected before the body is read, so the body is
+        // still open and only a cancel from the downloader can close it.
+        let cancelled = false;
+        const fetch = (async () =>
+            new Response(
+                new ReadableStream<Uint8Array>({
+                    start(controller) {
+                        controller.enqueue(multiChunk.body);
+                    },
+                    cancel() {
+                        cancelled = true;
+                    },
+                }),
+                { status: 200 },
+            )) as typeof globalThis.fetch;
+        const api = new ApiClient({ fetch, retry: { ...noWait, attempts: 1 } });
+        const shortHeader = multiChunk.header.subarray(0, 5);
+        const file = buildMockEnteFile(multiChunkKey, shortHeader, shortHeader);
+        const outPath = join(mkdtempSync(join(testDir, "cancel-")), "c.bin");
+
+        await expect(downloadFile(api, file, outPath)).rejects.toThrow();
+
+        expect(cancelled).toBe(true);
+    });
 });
 
 // ---------------------------------------------------------------------------
@@ -1396,7 +1568,13 @@ describe("writeAtomic", () => {
         // directory so that new entry is on disk too. Do the directory fsync
         // before the rename, or skip it, and a crash can lose the rename.
         expect(durabilityHook.events).toHaveLength(3);
-        expect(durabilityHook.events[0]).toMatch(/^sync:w:.*\.tmp$/);
+        // The temp name carries this process's ID, so a library opening the
+        // same cache can tell a write in progress from a leftover.
+        const tempSync = durabilityHook.events[0]!;
+        expect(tempSync.startsWith(`sync:w:${dir}/`)).toBe(true);
+        expect(tempSync.slice(`sync:w:${dir}/`.length)).toMatch(
+            new RegExp(`^\\.quak-${process.pid}-[0-9a-f]{32}\\.tmp$`),
+        );
         expect(durabilityHook.events[1]).toBe(`rename:${dest}`);
         expect(durabilityHook.events[2]).toBe(`sync:r:${dir}`);
     });
@@ -1471,3 +1649,250 @@ describe.each(entryPoints)("$name progress", ({ name, download }) => {
         expectSameBytes(readFileSync(outPath), plaintext);
     });
 });
+
+// Node's own BLAKE2b-512 is the reference, so the tests below do not depend on
+// the code under test to compute what they expect.
+const blake2b = (bytes: Uint8Array): string =>
+    createHash("blake2b512").update(bytes).digest("base64");
+
+// Serve `plaintext` encrypted as file 999 with the given metadata, to be
+// written to `f.bin` in a fresh directory. Four responses are scripted so a
+// retried failure would show in `requests`.
+const setup = (plaintext: Uint8Array, metadata: Partial<FileMetadata>) => {
+    const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+    const { header, ciphertext } = encryptFileBody(plaintext, key);
+    const file = buildMockEnteFile(key, header, header);
+    file.metadata = { ...file.metadata, ...metadata };
+    const body = { kind: "body", bytes: ciphertext } as const;
+    const { fetch, requests } = scriptedCdnFetch(body, body, body, body);
+    const api = new ApiClient({ fetch, retry: { ...noWait, attempts: 4 } });
+    const dir = mkdtempSync(join(testDir, "hash-"));
+    const outPath = join(dir, "f.bin");
+    return {
+        run: () => downloadFile(api, file, outPath),
+        api,
+        file,
+        dir,
+        outPath,
+        requests,
+    };
+};
+
+describe("downloadFile content hash", () => {
+    it("stores a file whose hash matches", async () => {
+        const plaintext = patternBytes(700, 80);
+        const t = setup(plaintext, { hash: blake2b(plaintext) });
+
+        await t.run();
+
+        expectSameBytes(readFileSync(t.outPath), plaintext);
+    });
+
+    it("rejects a mismatch, stores nothing, names the file and does not retry", async () => {
+        const t = setup(patternBytes(700, 80), {
+            hash: blake2b(patternBytes(700, 79)),
+        });
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: content hash .* does not match/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual([]);
+        expect(t.requests()).toBe(1);
+    });
+
+    it("stores a file with no recorded hash unchecked", async () => {
+        const plaintext = patternBytes(700, 80);
+        const t = setup(plaintext, { hash: undefined });
+
+        await t.run();
+
+        expectSameBytes(readFileSync(t.outPath), plaintext);
+    });
+
+    it("stores a live photo whose image and video hashes match", async () => {
+        const t = setup(livePhotoZip(), {
+            fileType: "livePhoto",
+            hash: livePhotoHash(),
+        });
+
+        await t.run();
+
+        expect(readFileSync(join(t.dir, "f.heic"))).toEqual(Buffer.from(IMAGE));
+        expect(readFileSync(join(t.dir, "f.mov"))).toEqual(Buffer.from(VIDEO));
+    });
+
+    it("writes a large live photo entry as it decompresses, never whole", async () => {
+        // 64 MiB of zeros deflates to a few kilobytes, the shape of a ZIP
+        // that would exhaust memory if expanded whole.
+        const image = new Uint8Array(64 * 1024 * 1024);
+        const video = patternBytes(900, 83);
+        const zip = zipSync({ "image.heic": image, "video.mov": video });
+        const t = setup(zip, {
+            fileType: "livePhoto",
+            hash: livePhotoHash(image, video),
+        });
+
+        await t.run();
+
+        expect(statSync(join(t.dir, "f.heic")).size).toBe(image.length);
+        expectSameBytes(readFileSync(join(t.dir, "f.mov")), video);
+        const hashed = hashHook.lengths.reduce((a, b) => a + b, 0);
+        expect(hashed).toBe(image.length + video.length);
+        expect(Math.max(...hashHook.lengths)).toBeLessThanOrEqual(
+            2 * STREAM_CHUNK_SIZE,
+        );
+        const written = writeHook.writes.filter((w) => w.path.endsWith(".tmp"));
+        expect(Math.max(...written.map((w) => w.length))).toBeLessThanOrEqual(
+            2 * STREAM_CHUNK_SIZE,
+        );
+    });
+
+    it("rejects a live photo whose hash does not match, keeping what was there", async () => {
+        // The whole ZIP's hash is not the recorded one: each part is hashed.
+        const zip = livePhotoZip();
+        const t = setup(zip, { fileType: "livePhoto", hash: blake2b(zip) });
+        writeFileSync(t.outPath, "an earlier download");
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: content hash .* does not match/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual(["f.bin"]);
+        expect(readFileSync(t.outPath, "utf-8")).toBe("an earlier download");
+    });
+
+    it("rejects a live photo that is not a readable ZIP and does not retry", async () => {
+        // Bytes 8-9 of a ZIP entry's local header name its compression
+        // method; 99 is one no reader knows, so the entry cannot be read.
+        const zip = livePhotoZip();
+        zip[8] = 99;
+        zip[9] = 0;
+        const t = setup(zip, { fileType: "livePhoto", hash: livePhotoHash() });
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: live photo is not a readable ZIP/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual([]);
+        expect(t.requests()).toBe(1);
+    });
+
+    it("rejects a live photo ZIP with no image entry", async () => {
+        const zip = livePhotoZip({ "video.mov": VIDEO });
+        const t = setup(zip, { fileType: "livePhoto", hash: livePhotoHash() });
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: live photo ZIP does not hold both an image and a video/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual([]);
+    });
+
+    it("rejects a live photo ZIP with no video entry", async () => {
+        const zip = livePhotoZip({ "image.heic": IMAGE });
+        const t = setup(zip, { fileType: "livePhoto", hash: livePhotoHash() });
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: live photo ZIP does not hold both an image and a video/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual([]);
+    });
+});
+
+// ---------------------------------------------------------------------------
+// Live photos
+//
+// A live photo arrives as a ZIP of its image and its video. It is written as
+// those two files, which a photo viewer can open, each named after the
+// destination with its own extension from the ZIP, the way Ente's clients name
+// them when they save one.
+// ---------------------------------------------------------------------------
+
+describe("downloadFile live photos", () => {
+    const livePhoto = { fileType: "livePhoto", hash: livePhotoHash() } as const;
+
+    it("names the image and the video after the title when no outPath is given", async () => {
+        const t = setup(livePhotoZip(), {
+            ...livePhoto,
+            title: "IMG_1234.HEIC",
+        });
+
+        const result = await inDirectory(t.dir, () =>
+            downloadFile(t.api, t.file),
+        );
+
+        // `bytesWritten` is the length of the decrypted ZIP.
+        expect(result).toEqual({
+            path: "IMG_1234.heic",
+            videoPath: "IMG_1234.mov",
+            bytesWritten: livePhotoZip().length,
+        });
+        expect(readdirSync(t.dir).sort()).toEqual([
+            "IMG_1234.heic",
+            "IMG_1234.mov",
+        ]);
+    });
+
+    it("gives each part its own extension from the ZIP, letters and digits only", async () => {
+        const zip = livePhotoZip({ "image.JPG": IMAGE, "video.m-4v": VIDEO });
+        const t = setup(zip, livePhoto);
+
+        const result = await downloadFile(t.api, t.file, join(t.dir, "f.HEIC"));
+
+        expect(result.path).toBe(join(t.dir, "f.JPG"));
+        expect(result.videoPath).toBe(join(t.dir, "f.bin"));
+        expect(readdirSync(t.dir).sort()).toEqual(["f.JPG", "f.bin"]);
+    });
+
+    it("replaces what was at the destination, such as an earlier ZIP of the two", async () => {
+        const t = setup(livePhotoZip(), livePhoto);
+        writeFileSync(t.outPath, livePhotoZip());
+
+        await t.run();
+
+        expect(readdirSync(t.dir).sort()).toEqual(["f.heic", "f.mov"]);
+    });
+
+    it("renames the image and then the video into place, each from its own temp file", async () => {
+        const t = setup(livePhotoZip(), livePhoto);
+
+        await t.run();
+
+        expect(
+            renameHook.calls.map((c) => [
+                dirname(c.from),
+                c.to,
+                c.sourceExisted,
+            ]),
+        ).toEqual([
+            [t.dir, join(t.dir, "f.heic"), true],
+            [t.dir, join(t.dir, "f.mov"), true],
+        ]);
+    });
+
+    it("stores neither part when the video cannot be renamed into place", async () => {
+        const t = setup(livePhotoZip(), livePhoto);
+        renameHook.failWith = new Error("simulated rename failure");
+        renameHook.failTo = join(t.dir, "f.mov");
+
+        await expect(t.run()).rejects.toThrow("simulated rename failure");
+
+        expect(readdirSync(t.dir)).toEqual([]);
+    });
+
+    it("refuses an image and a video with the same extension, storing nothing", async () => {
+        // On a file system that ignores case, the two would be one file.
+        const zip = livePhotoZip({ "image.mov": IMAGE, "video.MOV": VIDEO });
+        const t = setup(zip, livePhoto);
+        writeFileSync(t.outPath, "an earlier download");
+
+        await expect(t.run()).rejects.toThrow(
+            /file 999: live photo's image and video have the same extension/,
+        );
+
+        expect(readdirSync(t.dir)).toEqual(["f.bin"]);
+        expect(t.requests()).toBe(1);
+    });
+});

test/library/content-library.test.ts

@@ -116,7 +116,7 @@ describe("Library content wiring", () => {
         expect(lib.photos.byID({ fileID: 1 })!.record().thumbnailPath).toBe(
             result.path,
         );
-        lib.close();
+        await lib.close();
     });
 
     it("drives thumbnails.ensure through the cache", async () => {
@@ -139,7 +139,7 @@ describe("Library content wiring", () => {
         expect(results).toEqual([
             { fileID: 1, path: join(root, "cache", "thumbnails", "1.jpg") },
         ]);
-        lib.close();
+        await lib.close();
     });
 
     it("throws from content methods when opened without a content source", async () => {
@@ -155,6 +155,6 @@ describe("Library content wiring", () => {
         await expect(
             lib.thumbnails.ensure({ fileIDs: [1], priority: "visible" }),
         ).rejects.toThrow(/content cache/i);
-        lib.close();
+        await lib.close();
     });
 });

test/library/content.test.ts

@@ -31,8 +31,11 @@ import {
     existsSync,
     writeFileSync,
     mkdirSync,
+    readdirSync,
+    readFileSync,
     statSync,
 } from "node:fs";
+import { spawnSync } from "node:child_process";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 
@@ -43,6 +46,13 @@ import {
 } from "../../src/library/content.js";
 import { RequestPools } from "../../src/library/pools.js";
 import type { EnteFile } from "../../src/model/types.js";
+import {
+    asLivePhoto,
+    cdnSource,
+    IMAGE,
+    livePhotoZip,
+    VIDEO,
+} from "../live-photo.js";
 
 const file = (id: number, title = `file-${id}.jpg`): EnteFile => ({
     id,
@@ -161,15 +171,28 @@ describe("ContentCache.open", () => {
         expect(statSync(thumbnails).mode & 0o777).toBe(0o700);
     });
 
-    it("reaps orphan temp files but keeps complete content", async () => {
+    it("removes temp files of an exited process, keeping those of a running one and complete content", async () => {
         const originals = join(cacheDir, "originals");
         const thumbnails = join(cacheDir, "thumbnails");
         mkdirSync(originals, { recursive: true });
         mkdirSync(thumbnails, { recursive: true });
-        const orphan = join(originals, ".quak-abc123.tmp");
+        // A child that has already exited: its process ID is not running.
+        const exitedPID = spawnSync(process.execPath, ["-e", ""]).pid;
+        const orphan = join(originals, `.quak-${exitedPID}-abc123.tmp`);
+        const orphanThumb = join(thumbnails, `.quak-${exitedPID}-abc456.tmp`);
+        // This test's own process stands in for another process still
+        // downloading into the same cache.
+        const inProgress = join(originals, `.quak-${process.pid}-def123.tmp`);
+        const inProgressThumb = join(
+            thumbnails,
+            `.quak-${process.pid}-def456.tmp`,
+        );
         const complete = join(originals, "1.jpg");
         const thumb = join(thumbnails, "2.jpg");
         writeFileSync(orphan, "half-written");
+        writeFileSync(orphanThumb, "half-written");
+        writeFileSync(inProgress, "half-written");
+        writeFileSync(inProgressThumb, "half-written");
         writeFileSync(complete, "whole");
         writeFileSync(thumb, "whole-thumb");
 
@@ -177,8 +200,12 @@ describe("ContentCache.open", () => {
         await cache.open();
 
         expect(existsSync(orphan)).toBe(false);
+        expect(existsSync(orphanThumb)).toBe(false);
+        expect(existsSync(inProgress)).toBe(true);
+        expect(existsSync(inProgressThumb)).toBe(true);
         expect(existsSync(complete)).toBe(true);
         expect(existsSync(thumb)).toBe(true);
+        expect(cache.pathsFor(1)).toEqual({ originalPath: complete });
     });
 
     it("records already-cached files so their paths appear in pathsFor", async () => {
@@ -440,3 +467,125 @@ describe("ContentCache.ensureThumbnails", () => {
         expect(results[1]?.error).toMatch(/unknown file/i);
     });
 });
+
+// A live photo's original is two files, its image and its video, which a
+// photo viewer can open, and a JSON file naming them: the two are named with
+// the extensions from inside the ZIP, so the names alone do not say which is
+// which. These tests download a live photo ZIP through the real download
+// layer (test/live-photo.ts).
+describe("ContentCache live photos", () => {
+    const originals = (): string => join(cacheDir, "originals");
+
+    // A cache over the stand-in server, which holds `bodies` by file ID.
+    const cacheOf = (
+        files: EnteFile[],
+        bodies: Map<number, Uint8Array>,
+    ): ContentCache => buildCache({ files, source: cdnSource(bodies) }).cache;
+
+    it("stores a live photo as its image and its video and a JSON file naming them", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        const result = await cache.original(5);
+
+        expect(result).toEqual({
+            path: join(originals(), "5.heic"),
+            videoPath: join(originals(), "5.mov"),
+            bytes: IMAGE.length,
+        });
+        expect(readFileSync(result.path)).toEqual(Buffer.from(IMAGE));
+        expect(readFileSync(result.videoPath!)).toEqual(Buffer.from(VIDEO));
+        expect(statSync(result.videoPath!).mode & 0o777).toBe(0o600);
+        expect(
+            JSON.parse(
+                readFileSync(join(originals(), "5.livephoto.json"), "utf-8"),
+            ),
+        ).toEqual({ image: "5.heic", video: "5.mov" });
+        expect(cache.pathsFor(5)).toEqual({ originalPath: result.path });
+    });
+
+    it("serves a stored live photo from disk after the cache is opened again", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        const first = cacheOf([live], new Map([[5, body]]));
+        await first.open();
+        const stored = await first.original(5);
+
+        // This server has nothing, so a fetch would fail.
+        const second = cacheOf([live], new Map());
+        await second.open();
+        const events: string[] = [];
+        const served = await second.original(5, {
+            onProgress: (e) => events.push(e.status),
+        });
+
+        expect(served).toEqual(stored);
+        expect(events).toEqual(["skipped"]);
+    });
+
+    it("replaces a live photo an earlier version stored as a ZIP under the image's name", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        mkdirSync(originals(), { recursive: true });
+        writeFileSync(join(originals(), "5.HEIC"), livePhotoZip());
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        const result = await cache.original(5);
+
+        expect(result.videoPath).toBe(join(originals(), "5.mov"));
+        expect(readdirSync(originals()).sort()).toEqual([
+            "5.heic",
+            "5.livephoto.json",
+            "5.mov",
+        ]);
+    });
+
+    it("evicts a live photo's image, video and JSON file together", async () => {
+        const a = await asLivePhoto(file(5, "a.HEIC"));
+        const b = await asLivePhoto(file(6, "b.HEIC"));
+        const size = IMAGE.length + VIDEO.length;
+        const cache = new ContentCache({
+            pools: new RequestPools(),
+            source: cdnSource(
+                new Map([
+                    [5, a.body],
+                    [6, b.body],
+                ]),
+            ),
+            cacheDirectory: cacheDir,
+            getFile: (id) => [a.file, b.file].find((f) => f.id === id),
+            // Room for one live photo, on a disk with plenty free.
+            cacheOriginalsMaxBytes: size,
+            freeBelowBytes: 0,
+            statfs: async () => ({ bsize: 1, bavail: 1e12 }),
+        });
+        await cache.open();
+
+        await cache.original(5);
+        await cache.original(6);
+
+        expect(readdirSync(originals()).sort()).toEqual([
+            "6.heic",
+            "6.livephoto.json",
+            "6.mov",
+        ]);
+        expect(cache.originalsStatus().usedBytes).toBe(size);
+    });
+
+    it("stores nothing when a live photo does not match its recorded hash", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(5, "IMG_5.HEIC"),
+            livePhotoZip(),
+            "not:the recorded hash",
+        );
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        await expect(cache.original(5)).rejects.toThrow(
+            /file 5: content hash .* does not match/,
+        );
+
+        expect(readdirSync(originals())).toEqual([]);
+        expect(cache.pathsFor(5)).toEqual({});
+    });
+});

test/library/fresh.test.ts

@@ -179,7 +179,7 @@ describe("Library.fresh", () => {
             // And the change is now live for the default namespaces too.
             expect(lib.photos.byID({ fileID: 1002 })?.fileID).toBe(1002);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -228,7 +228,7 @@ describe("Library.fresh", () => {
                 expect(reads.photos.byID({ fileID: 1002 })?.fileID).toBe(1002);
             }
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -266,7 +266,7 @@ describe("Library.fresh", () => {
             );
             expect(lib.status().lastError).toBeUndefined();
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 });

test/library/library.test.ts

@@ -17,7 +17,8 @@
  *    failure surfaces via `onProgress` ("failed") and `status()`, and a later
  *    success clears the error. `open()` itself resolves even when the first
  *    refresh fails (offline start from cache).
- * 5. `close()` stops the timer and is idempotent.
+ * 5. `close()` stops the timer and is idempotent, and its promise resolves
+ *    only once an in-flight refresh has written the cache file.
  * 6. `cacheDirectory` defaults to the env-paths cache dir plus the user id.
  * 7. `open()` branches on the cache: an empty cache awaits the first refresh
  *    (it has nothing to serve yet); an existing cache serves its copy at once
@@ -37,6 +38,11 @@
  * short interval and `vi.waitFor`: a fake clock cannot settle the real
  * fsync-and-rename cache write, and empty diffs never write, so the eventual
  * state is stable to poll for.
+ *
+ * A refresh changes RAM before it writes the cache file, so a polled state can
+ * be visible while that write is still running. Every test therefore awaits
+ * `close()`, which waits for the in-flight refresh, before `afterEach` removes
+ * the directory.
  */
 
 import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
@@ -193,7 +199,7 @@ describe("Library.open and background refresh", () => {
             expect(reloaded.getFile(1, 1001)?.id).toBe(1001);
             expect(reloaded.collectionsSinceTime).toBe(100);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -224,7 +230,7 @@ describe("Library.open and background refresh", () => {
             expect(client.collectionsSinceTimes.length).toBe(collectionCalls);
             expect(client.filesCalls.length).toBe(fileCalls);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -271,7 +277,7 @@ describe("Library.open and background refresh", () => {
                 { timeout: 2000, interval: 5 },
             );
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -303,7 +309,7 @@ describe("Library.open and background refresh", () => {
             // never re-fetched.
             expect(client.filesCalls).toEqual([]);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -357,7 +363,7 @@ describe("Library.open and background refresh", () => {
                 { timeout: 2000, interval: 5 },
             );
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -402,7 +408,7 @@ describe("Library.open and background refresh", () => {
             await new Promise((r) => setTimeout(r, FAST_INTERVAL * 1000 * 4));
             expect(saveSpy).toHaveBeenCalledTimes(2);
         } finally {
-            lib.close();
+            await lib.close();
             saveSpy.mockRestore();
         }
     });
@@ -462,7 +468,7 @@ describe("Library.open and background refresh", () => {
                 { timeout: 2000, interval: 5 },
             );
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -488,7 +494,7 @@ describe("Library.open and background refresh", () => {
                 ),
             ).toBe(true);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -502,9 +508,14 @@ describe("Library.open and background refresh", () => {
         seed.putFile(file(1001, 1, 400));
         await seed.save();
 
-        // The server never answers this run's first refresh.
+        // The server does not answer this run's first refresh until the test
+        // is done with it.
+        let answerFirstFetch: (page: CollectionsPage) => void = () => {};
         const client = new MockClient();
-        client.collectionsSince = () => new Promise<CollectionsPage>(() => {});
+        client.collectionsSince = () =>
+            new Promise<CollectionsPage>((resolve) => {
+                answerFirstFetch = resolve;
+            });
 
         // open() must resolve from the cache without blocking on the network,
         // and reads must serve the seeded copy.
@@ -517,7 +528,9 @@ describe("Library.open and background refresh", () => {
             expect(lib.status().lastRefreshAt).toBeUndefined();
             expect(lib.status().lastError).toBeUndefined();
         } finally {
-            lib.close();
+            // close() waits for the outstanding refresh, so let it finish.
+            answerFirstFetch({ collections: [], deleted: [], cursor: 500 });
+            await lib.close();
         }
     });
 
@@ -564,7 +577,7 @@ describe("Library.open and background refresh", () => {
             expect(lib.listFiles(1).map((f) => f.id)).toEqual([1001]);
             expect(lib.status().lastRefreshAt).toBeGreaterThan(0);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -619,7 +632,7 @@ describe("Library.open and background refresh", () => {
             );
             expect(reloaded.getFile(1, 1001)?.id).toBe(1001);
         } finally {
-            lib.close();
+            await lib.close();
             saveSpy.mockRestore();
         }
     });
@@ -634,8 +647,8 @@ describe("Library.open and background refresh", () => {
         });
         const callsAfterOpen = client.collectionsSinceTimes.length;
 
-        lib.close();
-        lib.close(); // second close must not throw
+        await lib.close();
+        await lib.close(); // second close must not throw
         expect(lib.status().closed).toBe(true);
 
         // No further refreshes fire once closed.
@@ -643,6 +656,65 @@ describe("Library.open and background refresh", () => {
         expect(client.collectionsSinceTimes.length).toBe(callsAfterOpen);
     });
 
+    it("close() resolves only after an in-flight refresh has written the cache", async () => {
+        const path = join(cacheDirectory, "metadata.json");
+        const seed = await MetadataStore.load(path);
+        seed.userID = USER_ID;
+        seed.collectionsSinceTime = 500;
+        seed.putCollection(collection(1, 400));
+        seed.putFile(file(1001, 1, 400));
+        await seed.save();
+
+        const client = new MockClient();
+        client.collectionsQueue.push({
+            collections: [collection(1, 600)],
+            deleted: [],
+            cursor: 600,
+        });
+        client.filesFor(1, {
+            files: [file(1002, 1, 600)],
+            deleted: [],
+            cursor: 600,
+        });
+
+        // Hold the refresh's cache write until the test releases it.
+        const realSave = MetadataStore.prototype.save;
+        let releaseSave: () => void = () => {};
+        const saveHeld = new Promise<void>((resolve) => {
+            releaseSave = resolve;
+        });
+        const saveSpy = vi
+            .spyOn(MetadataStore.prototype, "save")
+            .mockImplementation(async function (this: MetadataStore) {
+                await saveHeld;
+                return realSave.call(this);
+            });
+
+        const lib = await Library.open({ client, cacheDirectory });
+        try {
+            await vi.waitFor(() => expect(saveSpy).toHaveBeenCalled(), {
+                timeout: 2000,
+                interval: 5,
+            });
+
+            let closed = false;
+            const closing = lib.close().then(() => {
+                closed = true;
+            });
+            await new Promise((r) => setTimeout(r, 50));
+            expect(closed).toBe(false);
+
+            releaseSave();
+            await closing;
+            const reloaded = await MetadataStore.load(path);
+            expect(reloaded.getFile(1, 1002)?.id).toBe(1002);
+        } finally {
+            releaseSave();
+            await lib.close();
+            saveSpy.mockRestore();
+        }
+    });
+
     it("defaults cacheDirectory to the env-paths cache dir plus user id", async () => {
         const xdg = join(dir, "xdg-cache");
         const prev = process.env.XDG_CACHE_HOME;
@@ -659,7 +731,7 @@ describe("Library.open and background refresh", () => {
                 expect(lib.cacheDirectory.startsWith(xdg)).toBe(true);
                 expect(lib.cacheDirectory.endsWith(String(USER_ID))).toBe(true);
             } finally {
-                lib.close();
+                await lib.close();
             }
         } finally {
             if (prev === undefined) delete process.env.XDG_CACHE_HOME;

test/library/mldata.test.ts

@@ -13,6 +13,8 @@
  *   2. `Library` wiring: after each refresh the library fetches ML data through
  *      the metadata pool for every known file not yet cached, is incremental on
  *      later refreshes, and refetches a file whose `updationTime` advanced.
+ *      Opening a cache directory written by another account starts empty,
+ *      its ML data included (issue #104).
  *
  * Embedding values are chosen to be exactly representable as float32 so the
  * round-trip through `clip.f32` compares equal.
@@ -374,7 +376,7 @@ describe("Library ML-data fetch on refresh", () => {
             await new Promise((r) => setTimeout(r, FAST_INTERVAL * 1000 * 5));
             expect(client.mlFetchCalls.length).toBe(callsAfterFirst);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -443,7 +445,118 @@ describe("Library ML-data fetch on refresh", () => {
             expect(client.mlFetchCalls.length).toBeGreaterThan(callsBefore);
             expect(client.mlFetchCalls.flat()).toContain(1001);
         } finally {
-            lib.close();
+            await lib.close();
+        }
+    });
+
+    it("close() resolves only after a running ML data fetch has stored its payloads", async () => {
+        const client = new MLMockClient();
+        client.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+        client.filesFor(1, {
+            files: [file(1001, 1, 90)],
+            deleted: [],
+            cursor: 90,
+        });
+        client.mlByFile.set(1001, payload([0.5, 0.25, 0.75]));
+
+        // Hold the ML data fetch open until the test releases it.
+        let release!: () => void;
+        const held = new Promise<void>((r) => (release = r));
+        let fetchStarted!: () => void;
+        const started = new Promise<void>((r) => (fetchStarted = r));
+        const realFetch = client.fetchMLData.bind(client);
+        client.fetchMLData = async (args) => {
+            fetchStarted();
+            await held;
+            return realFetch(args);
+        };
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: 3600,
+        });
+        try {
+            await started;
+
+            let closed = false;
+            const closing = lib.close().then(() => {
+                closed = true;
+            });
+            await new Promise((r) => setTimeout(r, 20));
+            expect(closed).toBe(false);
+
+            release();
+            await closing;
+            expect(
+                existsSync(join(cacheDirectory, "mldata", "1001.json")),
+            ).toBe(true);
+        } finally {
+            release();
+            await lib.close();
+        }
+    });
+
+    it("starts empty when the cache directory holds another account's cache", async () => {
+        // Account A fills the cache directory: metadata and ML data.
+        const clientA = new MLMockClient();
+        clientA.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+        clientA.filesFor(1, {
+            files: [file(1001, 1, 90)],
+            deleted: [],
+            cursor: 90,
+        });
+        clientA.mlByFile.set(1001, payload([0.5, 0.25, 0.75]));
+        const libA = await Library.open({
+            client: clientA,
+            cacheDirectory,
+            refreshIntervalSeconds: 3600,
+        });
+        try {
+            await vi.waitFor(
+                () => expect(libA.status().lastMLFetchAt).toBeGreaterThan(0),
+                { timeout: 2000, interval: 5 },
+            );
+        } finally {
+            await libA.close();
+        }
+
+        // Account B opens the same directory.
+        const clientB = new MLMockClient();
+        clientB.userID = USER_ID + 1;
+        const sinceTimes: number[] = [];
+        const realCollectionsSince = clientB.collectionsSince.bind(clientB);
+        clientB.collectionsSince = async (args) => {
+            sinceTimes.push(args.sinceTime);
+            return realCollectionsSince(args);
+        };
+        const libB = await Library.open({
+            client: clientB,
+            cacheDirectory,
+            refreshIntervalSeconds: 3600,
+        });
+        try {
+            expect(sinceTimes[0]).toBe(0);
+            expect(libB.status().userID).toBe(USER_ID + 1);
+            expect(libB.listCollections()).toEqual([]);
+            expect(libB.getFile(1, 1001)).toBeUndefined();
+            expect(await libB.mldata.forFile({ fileID: 1001 })).toBeUndefined();
+            expect(
+                libB.mldata.searchByEmbedding({ embedding: [0.5, 0.25, 0.75] }),
+            ).toEqual([]);
+            expect(
+                existsSync(join(cacheDirectory, "mldata", "1001.json")),
+            ).toBe(false);
+        } finally {
+            await libB.close();
         }
     });
 });

test/library/precache.test.ts

@@ -402,35 +402,97 @@ describe("Precache through Library.open", () => {
     }
 
     it("starts both precaches from open() and reports them in status()", async () => {
-        const thumbFetched = new Set<number>();
-        const origFetched = new Set<number>();
         const source: ContentSource = {
-            original: async ({ file: f, destination }) => {
-                origFetched.add(f.id);
+            original: async ({ destination }) => {
                 await writeFile(destination, Buffer.alloc(10, 1));
                 return { bytesWritten: 10 };
             },
-            thumbnail: async ({ file: f, destination }) => {
-                thumbFetched.add(f.id);
+            thumbnail: async ({ destination }) => {
                 await writeFile(destination, Buffer.alloc(10, 1));
                 return { bytesWritten: 10 };
             },
         };
+        // Each fill reports "done" once the cache has recorded its files. The
+        // source returning is not enough: the cache records a file only after
+        // it has checked it on disk.
+        const finished = new Set<string>();
+        let bothFinished!: () => void;
+        const precached = new Promise<void>((r) => (bothFinished = r));
         const lib = await Library.open({
             client: new MockClient(),
             cacheDirectory: join(root, "cache"),
             contentSource: source,
             refreshIntervalSeconds: 3600,
+            onProgress: (e) => {
+                if (
+                    e.status === "done" &&
+                    (e.operation === "precacheThumbnails" ||
+                        e.operation === "precacheOriginals")
+                ) {
+                    finished.add(e.operation);
+                    if (finished.size === 2) bothFinished();
+                }
+            },
         });
 
         // Every file's thumbnail is precached; the favorite (file 3) and the
         // week's files (1, 2) all have their originals precached.
-        await until(() => thumbFetched.size === 3 && origFetched.size === 3);
+        await precached;
         const status = lib.status();
         expect(status.thumbnailsTotal).toBe(3);
         expect(status.thumbnailsCached).toBe(3);
         expect(status.originalsPinned).toBe(3);
         expect(status.originalsCached).toBe(3);
-        lib.close();
+        await lib.close();
     });
+
+    it.each(["thumbnail", "original"] as const)(
+        "close() resolves only after a running %s precache fetch has written its file",
+        async (kind) => {
+            // Only the fill under test runs, and each of its fetches waits
+            // until the test releases it.
+            let release!: () => void;
+            const held = new Promise<void>((r) => (release = r));
+            let fetchStarted!: (destination: string) => void;
+            const started = new Promise<string>((r) => (fetchStarted = r));
+            const fetch = async ({ destination }: { destination: string }) => {
+                fetchStarted(destination);
+                await held;
+                await writeFile(destination, Buffer.alloc(10, 1));
+                return { bytesWritten: 10 };
+            };
+            const unused = async () => {
+                throw new Error("this fill is turned off");
+            };
+            const source: ContentSource =
+                kind === "thumbnail"
+                    ? { original: unused, thumbnail: fetch }
+                    : { original: fetch, thumbnail: unused };
+            const lib = await Library.open({
+                client: new MockClient(),
+                cacheDirectory: join(root, "cache"),
+                contentSource: source,
+                refreshIntervalSeconds: 3600,
+                precacheThumbnails: kind === "thumbnail",
+                precacheOriginals: kind === "original",
+            });
+            try {
+                const destination = await started;
+
+                let closed = false;
+                const closing = lib.close().then(() => {
+                    closed = true;
+                });
+                await new Promise((r) => setTimeout(r, 20));
+                expect(closed).toBe(false);
+
+                release();
+                await closing;
+                expect(existsSync(destination)).toBe(true);
+            } finally {
+                release();
+                await lib.close();
+            }
+        },
+    );
 });

test/library/read.test.ts

@@ -531,7 +531,7 @@ describe("Library exposes the read surface over its live store", () => {
             expect(client.collectionsCalls).toBe(collectionsBefore);
             expect(client.filesCalls).toBe(filesBefore);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 });

test/library/snapshot.test.ts

@@ -159,7 +159,7 @@ describe("Library.snapshot and Library.subscribe", () => {
             for (const p of snap.photos) expect("key" in p).toBe(false);
             for (const a of snap.albums) expect("key" in a).toBe(false);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -219,7 +219,7 @@ describe("Library.snapshot and Library.subscribe", () => {
             expect(change.refreshedAt).toBeGreaterThan(0);
         } finally {
             unsubscribe();
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -251,7 +251,7 @@ describe("Library.snapshot and Library.subscribe", () => {
             expect(changes).toEqual([]);
         } finally {
             unsubscribe();
-            lib.close();
+            await lib.close();
         }
     });
 
@@ -297,7 +297,7 @@ describe("Library.snapshot and Library.subscribe", () => {
             );
             expect(changes).toEqual([]);
         } finally {
-            lib.close();
+            await lib.close();
         }
     });
 });

test/live-photo.ts

@@ -0,0 +1,77 @@
+/**
+ * Live photo fixtures for the download, content cache, backup and CLI tests.
+ *
+ * Ente stores a live photo as one ZIP holding its image and its video, which
+ * Ente's clients name `image.<ext>` and `video.<ext>`. The ZIP is built here
+ * with fflate from small fixed bytes and encrypted the way the server serves a
+ * file under 4 MiB, as one secretstream chunk. `cdnSource` serves it to the
+ * real download layer, so a test checks what quak stores for a real one.
+ */
+
+import { createHash } from "node:crypto";
+import { zipSync } from "fflate";
+
+import { ApiClient } from "../src/api/client.js";
+import { encryptBlob, init, toBase64 } from "../src/crypto/index.js";
+import {
+    makeDownloadContentSource,
+    type ContentSource,
+} from "../src/library/content.js";
+import type { EnteFile } from "../src/model/types.js";
+
+export const IMAGE = new TextEncoder().encode("the still image");
+export const VIDEO = new TextEncoder().encode("the few seconds of video");
+
+// A live photo's ZIP; by default the entries an iPhone's live photo gets.
+export const livePhotoZip = (
+    entries: Record<string, Uint8Array> = {
+        "image.heic": IMAGE,
+        "video.mov": VIDEO,
+    },
+): Uint8Array => zipSync(entries);
+
+const blake2b = (bytes: Uint8Array): string =>
+    createHash("blake2b512").update(bytes).digest("base64");
+
+// The hash Ente's clients record for a live photo: the unkeyed BLAKE2b-512 of
+// the image and of the video, each in standard base64, joined by a colon.
+export const livePhotoHash = (image = IMAGE, video = VIDEO): string =>
+    `${blake2b(image)}:${blake2b(video)}`;
+
+// `file` as a live photo whose original is `zip` and whose recorded hash is
+// `hash`, and `body`, what the server serves for it: `zip` encrypted under the
+// file's key and header.
+export const asLivePhoto = async (
+    file: EnteFile,
+    zip = livePhotoZip(),
+    hash = livePhotoHash(),
+): Promise<{ file: EnteFile; body: Uint8Array }> => {
+    await init();
+    const key = new Uint8Array(32).fill(file.id & 0xff);
+    const { header, ciphertext } = encryptBlob(zip, key);
+    return {
+        file: {
+            ...file,
+            key,
+            metadata: { ...file.metadata, fileType: "livePhoto", hash },
+            file: { decryptionHeader: toBase64(header) },
+        },
+        body: ciphertext,
+    };
+};
+
+// A content source that downloads through the real download layer from a
+// stand-in server, which serves `bodies` by file ID and a 404 for any other.
+export const cdnSource = (bodies: Map<number, Uint8Array>): ContentSource =>
+    makeDownloadContentSource(
+        new ApiClient({
+            fetch: (async (url: string | URL) => {
+                const fileID = new URL(String(url)).searchParams.get("fileID");
+                const body = bodies.get(Number(fileID));
+                return body === undefined
+                    ? new Response("not found", { status: 404 })
+                    : new Response(body);
+            }) as typeof globalThis.fetch,
+            retry: { attempts: 1 },
+        }),
+    );

test/model/decrypt.test.ts

@@ -351,6 +351,46 @@ describe("model.decryptFile", () => {
         }
     });
 
+    it("reads the recorded content hash, joining an older live photo's two parts", () => {
+        const masterKey = sodium.crypto_secretbox_keygen();
+        const { collectionKey } = buildRawCollection(masterKey);
+        const hashOf = (metadata: Record<string, unknown>) =>
+            decryptFile(
+                buildRawFile(collectionKey, {
+                    metadata: { title: "x", ...metadata },
+                }),
+                collectionKey,
+            ).metadata.hash;
+
+        expect(hashOf({ fileType: 0, hash: "H" })).toBe("H");
+        expect(
+            hashOf({ fileType: 2, hash: "H", imageHash: "I", videoHash: "V" }),
+        ).toBe("H");
+        expect(hashOf({ fileType: 2, imageHash: "I", videoHash: "V" })).toBe(
+            "I:V",
+        );
+        expect(hashOf({ fileType: 2, imageHash: "I" })).toBeUndefined();
+        expect(
+            hashOf({ fileType: 0, imageHash: "I", videoHash: "V" }),
+        ).toBeUndefined();
+        expect(hashOf({ fileType: 0 })).toBeUndefined();
+        expect(hashOf({ fileType: 0, hash: 42 })).toBeUndefined();
+        expect(
+            hashOf({ fileType: 2, imageHash: "I", videoHash: 7 }),
+        ).toBeUndefined();
+        // An empty string counts as absent, not as a hash to match.
+        expect(hashOf({ fileType: 0, hash: "" })).toBeUndefined();
+        expect(
+            hashOf({ fileType: 2, hash: "", imageHash: "I", videoHash: "V" }),
+        ).toBe("I:V");
+        expect(
+            hashOf({ fileType: 2, imageHash: "", videoHash: "V" }),
+        ).toBeUndefined();
+        expect(
+            hashOf({ fileType: 2, imageHash: "I", videoHash: "" }),
+        ).toBeUndefined();
+    });
+
     it("maps fileType numbers to FileType strings", () => {
         // Ente uses: 0=image, 1=video, 2=livePhoto
         const masterKey = sodium.crypto_secretbox_keygen();

test/packaging/build-context.test.ts

@@ -2,13 +2,13 @@
 // failures are silent.
 //
 // Excluding too little: a worktree left under `.claude/` is copied into the
-// image, vitest globs its `test/` tree as well as the real one, and the
-// containerised `make check` runs the whole suite twice over while reporting
-// success. A compiled `bin/quak` is ~100 MB of context nobody needs.
+// image, vitest globs its `test/` tree as well as the real one, and the test
+// phase runs the whole suite twice over while reporting success. A compiled
+// `bin/quak` is ~100 MB of context nobody needs.
 //
 // Excluding too much: Prettier 3 reads `.gitignore` as a default ignore file,
-// so dropping it from the context silently changes which files
-// `make fmt-check` looks at inside the image compared to the host.
+// so dropping it from the context silently changes which files the lint
+// phase's prettier check looks at compared to `make fmt-check` on the host.
 //
 // Neither shows up as a build failure, so they are asserted here.
 import { describe, expect, it } from "vitest";
@@ -47,18 +47,13 @@ describe(".dockerignore", () => {
         expect(dockerignore).not.toContain(".gitignore");
     });
 
-    // Both images are built from this same context, and the lint image runs
-    // eslint and prettier across it. BuildKit lets a `<dockerfile>.dockerignore`
-    // shadow the root one for a single build; such a file would silently give
-    // the lint build a different, unreviewed context — and eslint's flat config
-    // does not ignore dot-directories, so a stray `.claude/` worktree would be
-    // linted.
-    it.each(["Dockerfile", "Dockerfile.lint"])(
-        "is not shadowed by a per-Dockerfile ignore file for %s",
-        (name) => {
-            expect(existsSync(join(repoRoot, `${name}.dockerignore`))).toBe(
-                false,
-            );
-        },
-    );
+    // BuildKit lets a `Dockerfile.dockerignore` shadow the root one; such a
+    // file would silently give the build a different, unreviewed context —
+    // and eslint's flat config does not ignore dot-directories, so a stray
+    // `.claude/` worktree would be linted.
+    it("is not shadowed by a Dockerfile.dockerignore", () => {
+        expect(existsSync(join(repoRoot, "Dockerfile.dockerignore"))).toBe(
+            false,
+        );
+    });
 });

test/packaging/entrypoints.test.ts

@@ -1,9 +1,7 @@
 // The package manifest promises three files that only exist after a build:
 // `main`, `types`, and the `quak` binary. Nothing in the test suite used to
-// look at them, and `make check` runs the suite and the lint container but
-// never the build, so `tsconfig.json` and `package.json` were free to drift
-// apart. (The formatting check is part of the lint container, not a step of
-// its own; `test/packaging/lint-once.test.ts` is what holds that shape.) They
+// look at them, and `make check` runs the test and lint phases but never the
+// build, so `tsconfig.json` and `package.json` were free to drift apart. They
 // did: `rootDir` was `./src` while `include` also pulled in `bin/**/*`, which
 // is TS6059, and no build had succeeded for as long as that was true.
 //

test/packaging/lint-docker.test.ts

@@ -1,184 +0,0 @@
-// Linting runs in Docker, one way, everywhere: `script/lint` builds
-// `Dockerfile.lint`, which COPYs the repo into a digest-pinned image and runs
-// eslint and prettier as build steps, so a successful build IS a clean lint.
-//
-// Three things can quietly undo that, and none of them shows up as a build
-// failure, which is why they are asserted here:
-//
-// 1. Recursion. `script/check` calls `script/lint`, and `script/lint` is now a
-//    `docker build`. Anything that runs `make check` inside a container is
-//    therefore asking for Docker inside Docker, and CI breaks. The image built
-//    from `Dockerfile` runs the suite and the compile only; lint happens once,
-//    in `Dockerfile.lint`.
-// 2. Cache. A lint build over an unchanged tree returns success in well under a
-//    second having linted nothing. The `LINT_EPOCH` guard is what forces the
-//    linter layers to execute, and it has to fail closed: an unset build
-//    argument is the empty string, which is a perfectly stable cache key, so an
-//    invocation that omits it must be rejected rather than served a cached
-//    green.
-// 3. A host lint path surviving alongside the container one, which would let a
-//    lint result come from an unpinned local toolchain.
-import { describe, expect, it } from "vitest";
-import { readFileSync } from "node:fs";
-import { fileURLToPath } from "node:url";
-import { join } from "node:path";
-
-const repoRoot = fileURLToPath(new URL("../../", import.meta.url));
-
-const read = (name: string): string =>
-    readFileSync(join(repoRoot, name), "utf-8");
-
-// The executable lines of a shell script or Dockerfile: comments carry the
-// reasoning and frequently name the very commands these tests forbid, so they
-// would otherwise trigger every assertion below.
-const instructions = (name: string): string[] =>
-    read(name)
-        .split("\n")
-        .map((line) => line.trim())
-        .filter((line) => line !== "" && !line.startsWith("#"));
-
-const lintScript = instructions("script/lint");
-const dockerfileLint = instructions("Dockerfile.lint");
-const dockerfile = instructions("Dockerfile");
-const cibuild = instructions("script/cibuild");
-
-const has = (lines: string[], pattern: RegExp): boolean =>
-    lines.some((line) => pattern.test(line));
-
-describe("script/lint", () => {
-    it("lints by building Dockerfile.lint", () => {
-        expect(has(lintScript, /docker build .*-f Dockerfile\.lint/)).toBe(
-            true,
-        );
-    });
-
-    // The whole point of the ruling: no invocation of a linter against the
-    // working tree survives, so a lint verdict can only come from the pinned
-    // image.
-    it("runs no linter on the host", () => {
-        expect(has(lintScript, /eslint|prettier/)).toBe(false);
-    });
-
-    // Without a fresh epoch the build is served from cache in under a second,
-    // having linted nothing, and still exits 0.
-    it("passes a fresh LINT_EPOCH on every run", () => {
-        expect(
-            has(lintScript, /--build-arg LINT_EPOCH="\$\(date \+%s\)"/),
-        ).toBe(true);
-    });
-});
-
-describe("Dockerfile.lint", () => {
-    // Tag references are server-mutable, so they are remote code execution.
-    it("pins its base image by digest", () => {
-        expect(has(dockerfileLint, /^FROM \S+@sha256:[0-9a-f]{64}/)).toBe(true);
-    });
-
-    it("runs eslint as a build step", () => {
-        expect(has(dockerfileLint, /^RUN .*eslint \./)).toBe(true);
-    });
-
-    it("runs prettier as a build step", () => {
-        expect(has(dockerfileLint, /^RUN .*prettier --check \./)).toBe(true);
-    });
-
-    // An unset ARG is the empty string, and an empty string is a perfectly
-    // stable cache key. Rejecting it is what stops a bare
-    // `docker build -f Dockerfile.lint .` from reporting a green it did not
-    // earn.
-    it("refuses to build without LINT_EPOCH", () => {
-        expect(has(dockerfileLint, /^ARG LINT_EPOCH$/)).toBe(true);
-        expect(
-            has(dockerfileLint, /^RUN \[ -n "\$LINT_EPOCH" \] \|\| exit 1$/),
-        ).toBe(true);
-    });
-
-    // The guard only forces execution of the layers below it, so both linters
-    // have to sit after it. Layer order is the mechanism, not a style choice.
-    it("puts both linters below the epoch guard", () => {
-        const guard = dockerfileLint.findIndex((line) =>
-            /^RUN \[ -n "\$LINT_EPOCH" \]/.test(line),
-        );
-        const linters = dockerfileLint
-            .map((line, index) => ({ line, index }))
-            .filter(({ line }) => /^RUN .*(eslint|prettier)/.test(line));
-
-        expect(linters.length).toBeGreaterThan(0);
-        for (const { line, index } of linters) {
-            expect(
-                index,
-                `${line} must run below the LINT_EPOCH guard`,
-            ).toBeGreaterThan(guard);
-        }
-    });
-
-    // Dependency installation is the slow layer and has nothing to do with the
-    // sources, so it caches separately: manifests first, sources afterwards.
-    it("copies the manifests before the sources", () => {
-        const manifests = dockerfileLint.findIndex((line) =>
-            /^COPY package\.json yarn\.lock/.test(line),
-        );
-        const sources = dockerfileLint.findIndex((line) =>
-            /^COPY \. \.$/.test(line),
-        );
-
-        expect(manifests).toBeGreaterThanOrEqual(0);
-        expect(sources).toBeGreaterThan(manifests);
-    });
-
-    // script/lint is a docker build; a lint step that shelled out to it would
-    // recurse.
-    it("does not call script/lint or make lint", () => {
-        expect(has(dockerfileLint, /make lint|script\/lint/)).toBe(false);
-    });
-});
-
-describe("Dockerfile", () => {
-    // `make check` runs script/lint, which is a docker build, so an image that
-    // ran it would need a Docker daemon inside the container.
-    it("does not run make check, make lint or script/lint", () => {
-        expect(
-            has(dockerfile, /make check|make lint|script\/(check|lint)/),
-        ).toBe(false);
-    });
-
-    // The replaced lint stage took a `COPY --from=lint` dependency to order
-    // itself before the check stage. Dockerfile.lint is that stage now, and
-    // two definitions of how to lint is one too many.
-    it("has no lint stage", () => {
-        expect(has(dockerfile, /AS lint\b|--from=lint\b/)).toBe(false);
-    });
-
-    it("still runs the suite and the build under the epoch guard", () => {
-        expect(has(dockerfile, /^RUN make test$/)).toBe(true);
-        expect(has(dockerfile, /^RUN make build$/)).toBe(true);
-        expect(
-            has(dockerfile, /^RUN \[ -n "\$CHECK_EPOCH" \] \|\| exit 1$/),
-        ).toBe(true);
-    });
-});
-
-describe("script/cibuild", () => {
-    // CI has to get both verdicts. Lint goes first so the fast failure is
-    // reported before the suite runs.
-    it("builds the lint image before the test and build image", () => {
-        const lint = cibuild.findIndex((line) => /\/lint"/.test(line));
-        const check = cibuild.findIndex((line) =>
-            /docker build .*CHECK_EPOCH/.test(line),
-        );
-
-        expect(lint).toBeGreaterThanOrEqual(0);
-        expect(check).toBeGreaterThan(lint);
-    });
-});
-
-describe("package.json", () => {
-    // `yarn lint` was a second, unpinned way to get a lint verdict, from
-    // whatever eslint the working tree happened to have installed.
-    it("exposes no host lint script", () => {
-        const pkg = JSON.parse(read("package.json")) as {
-            scripts: Record<string, string>;
-        };
-        expect(pkg.scripts.lint).toBeUndefined();
-    });
-});

test/packaging/lint-once.test.ts

@@ -1,503 +0,0 @@
-// `make check` used to run `prettier --check .` twice: once inside the lint
-// container (`script/lint` builds `Dockerfile.lint`, which runs eslint and
-// prettier as build steps) and once again on the host, because `script/check`
-// also called `script/fmt-check`. Two passes, one verdict, and the host one is
-// the weaker of the two — its prettier is whatever the working tree happens to
-// have installed, while the container's is digest-pinned and installed under
-// `--frozen-lockfile`.
-//
-// The fix was to delete the host call from `script/check` and `script/precommit`.
-// Nothing about that fix is self-enforcing: anyone can wire `script/fmt-check`
-// back in, or add a prettier step to a Dockerfile, and every build stays green
-// while quietly doing the work twice again. So the count is asserted here
-// rather than promised in a comment.
-//
-// The assertion is a static walk of the invocation graph, not a string match
-// against one file. Starting from an entrypoint, it follows every edge the repo
-// actually uses to reach another command — `run:` steps in the CI workflow,
-// `"$SCRIPT_DIR/<name>"` and `script/<name>` into other scripts, `make <target>`
-// through the Makefile shims, `yarn run <name>` through the `package.json`
-// scripts, and `docker build -f <file>` into that Dockerfile's `RUN` steps — and
-// counts the prettier invocations it finds. A prettier call added anywhere in
-// that graph is therefore caught, wherever it is added.
-//
-// Two entrypoints are walked, because they cover different graphs: `make check`
-// is what a developer runs, and `.gitea/workflows/check.yml` is what CI runs.
-// The CI walk starts at the workflow file rather than at a hand-picked script,
-// so "the path CI executes" is read out of the repo instead of assumed; it
-// reaches `script/cibuild`, and through it the `Dockerfile` image that `make
-// check` never touches. Walking only `make check` is how a duplicate prettier
-// pass in `Dockerfile` stayed invisible.
-//
-// Undercounting is the failure mode that would make this test worthless. Three
-// things guard against it: the walk is asserted to have reached the nodes that
-// matter, an unresolvable or empty node is a thrown error rather than a quiet
-// zero, and prettier is counted per occurrence rather than per line, so two
-// invocations chained with `&&` cannot read as one.
-import { describe, expect, it } from "vitest";
-import { readFileSync } from "node:fs";
-import { fileURLToPath } from "node:url";
-import { join } from "node:path";
-
-const repoRoot = fileURLToPath(new URL("../../", import.meta.url));
-
-const read = (name: string): string =>
-    readFileSync(join(repoRoot, name), "utf-8");
-
-// A backslash at end of line continues the command; the resolver has to see the
-// whole invocation, since the interesting flags (`-f Dockerfile.lint`) can sit
-// on the continuation.
-const joinContinuations = (text: string): string[] => {
-    const joined: string[] = [];
-    for (const raw of text.split("\n")) {
-        const line = raw.trim();
-        const previous = joined[joined.length - 1];
-        if (previous !== undefined && previous.endsWith("\\")) {
-            joined[joined.length - 1] =
-                `${previous.slice(0, -1).trim()} ${line}`;
-        } else {
-            joined.push(line);
-        }
-    }
-    return joined;
-};
-
-// Comments are stripped everywhere. The headers of these scripts explain the
-// duplication this test exists to prevent, and therefore name `prettier` and
-// `script/fmt-check` repeatedly; counting them would make the test assert the
-// prose instead of the behaviour.
-const executable = (text: string): string[] =>
-    joinContinuations(text).filter(
-        (line) => line !== "" && !line.startsWith("#"),
-    );
-
-// Every occurrence, not "does this line mention prettier": a line that reads
-// `yarn run prettier --check . && yarn run prettier --check src` is two passes
-// over the same tree, which is exactly the bug this file exists to catch, and
-// counting it as one would hide it. `.prettierrc` and `.prettierignore` are not
-// invocations and do not match, because `\b` requires a non-word character
-// after the name.
-const countPrettier = (line: string): number =>
-    (line.match(/\bprettier\b/g) ?? []).length;
-
-// Makefile targets are thin shims (`check:` / tab / `@script/check`), so a
-// `make <target>` edge has to resolve through them to keep "per `make check`"
-// meaning what it says. Recipe lines are the tab-indented ones.
-const makeRecipes = (): Map<string, string[]> => {
-    const recipes = new Map<string, string[]>();
-    let current: string | null = null;
-    for (const raw of read("Makefile").split("\n")) {
-        if (raw.startsWith("\t")) {
-            if (current !== null) {
-                recipes.get(current)?.push(raw.trim().replace(/^[@-]+/, ""));
-            }
-            continue;
-        }
-        const target = /^([a-z][a-z-]*)\s*:(?!=)/.exec(raw);
-        current = target === null ? null : target[1];
-        if (current !== null && !recipes.has(current)) {
-            recipes.set(current, []);
-        }
-    }
-    return recipes;
-};
-
-const recipes = makeRecipes();
-
-const packageScripts = (): Record<string, string> => {
-    const pkg = JSON.parse(read("package.json")) as {
-        scripts?: Record<string, string>;
-    };
-    return pkg.scripts ?? {};
-};
-
-const scripts = packageScripts();
-
-// Node keys: `script/<name>`, `docker:<Dockerfile>`, `make:<target>`,
-// `yarn:<package.json script>`, `workflow:<CI workflow file>`.
-const resolve = (node: string): string[] => {
-    if (node.startsWith("script/")) return executable(read(node));
-    if (node.startsWith("docker:")) {
-        return executable(read(node.slice("docker:".length)))
-            .filter((line) => line.startsWith("RUN "))
-            .map((line) => line.slice("RUN ".length));
-    }
-    // The `run:` steps of a workflow, in file order. `uses:` steps are actions,
-    // not commands, and have no edges into this repo's graph. A `run: |` block
-    // would resolve to the bare `|`, which reaches nothing and therefore fails
-    // the count rather than passing quietly.
-    if (node.startsWith("workflow:")) {
-        return executable(read(node.slice("workflow:".length)))
-            .filter((line) => /^-?\s*run:\s*\S/.test(line))
-            .map((line) => line.replace(/^-?\s*run:\s*/, ""));
-    }
-    if (node.startsWith("make:")) {
-        const target = node.slice("make:".length);
-        const recipe = recipes.get(target);
-        // A renamed or deleted target must be a loud failure: silently walking
-        // an empty recipe would report zero prettier invocations, which reads
-        // like the tidiest possible result.
-        if (recipe === undefined) {
-            throw new Error(`no such Makefile target: ${target}`);
-        }
-        return recipe;
-    }
-    if (node.startsWith("yarn:")) {
-        const name = node.slice("yarn:".length);
-        const script = scripts[name];
-        if (script === undefined) {
-            throw new Error(`no such package.json script: ${name}`);
-        }
-        return [script];
-    }
-    throw new Error(`unresolvable node: ${node}`);
-};
-
-// Same reasoning as the missing-target error, applied to every node kind: a
-// node that resolves to no commands contributes zero prettier invocations and
-// zero edges, which is indistinguishable from a clean result. Fail instead.
-const commandsOf = (node: string): string[] => {
-    const commands = resolve(node);
-    if (commands.length === 0) {
-        throw new Error(`node resolved to no commands: ${node}`);
-    }
-    return commands;
-};
-
-const edgesOf = (line: string): string[] => {
-    const edges: string[] = [];
-
-    // `"$SCRIPT_DIR/lint"`, `"$ROOT/script/lint"` and a bare `script/lint` are
-    // all the same edge.
-    for (const match of line.matchAll(
-        /(?:\$SCRIPT_DIR|\$\{SCRIPT_DIR\}|script)\/([a-z][a-z-]*)/g,
-    )) {
-        edges.push(`script/${match[1]}`);
-    }
-
-    // Only real targets: `pkg_install gnumake make make make` in
-    // script/bootstrap is a package name, not an invocation of this Makefile.
-    for (const match of line.matchAll(/\bmake\s+([a-z][a-z-]*)/g)) {
-        if (recipes.has(match[1] ?? "")) edges.push(`make:${match[1]}`);
-    }
-
-    // Same rule for yarn: `yarn run prettier` is the linter itself (counted,
-    // not followed), `yarn run fmt-check` would be a package.json script that
-    // runs it indirectly.
-    for (const match of line.matchAll(/\byarn(?:\s+run)?\s+([a-z][a-z-]*)/g)) {
-        if ((match[1] ?? "") in scripts) edges.push(`yarn:${match[1]}`);
-    }
-
-    // The container lint pass lives behind a `docker build`; without following
-    // it the count would miss the one invocation that is supposed to survive.
-    if (/\bdocker\s+build\b/.test(line)) {
-        const file = /\s-f\s+(\S+)/.exec(line);
-        edges.push(`docker:${file === null ? "Dockerfile" : file[1]}`);
-    }
-
-    return edges;
-};
-
-interface Walk {
-    prettier: number;
-    reached: Set<string>;
-}
-
-// Repeated invocations must count repeatedly — running the same script twice is
-// exactly the bug — so nodes are not deduplicated. The path stack is only there
-// to turn a cycle into a loud failure instead of a hang.
-//
-// Counting and edge-following both happen for every line: a line that invokes
-// prettier can also invoke something else, and skipping the edges of counted
-// lines silently truncated the graph.
-const walk = (node: string, path: string[] = [], into?: Walk): Walk => {
-    const result = into ?? { prettier: 0, reached: new Set<string>() };
-    if (path.includes(node)) {
-        throw new Error(`invocation cycle: ${[...path, node].join(" -> ")}`);
-    }
-    result.reached.add(node);
-
-    for (const line of commandsOf(node)) {
-        result.prettier += countPrettier(line);
-        for (const edge of edgesOf(line)) {
-            walk(edge, [...path, node], result);
-        }
-    }
-    return result;
-};
-
-describe("prettier runs exactly once per make check", () => {
-    const check = walk("make:check");
-
-    // The headline assertion, and the one the issue is about.
-    it("invokes prettier once for the whole of make check", () => {
-        expect(check.prettier).toBe(1);
-    });
-
-    // Guards against the count being 1 (or 0) because the walk never got
-    // anywhere. `make check` has to reach the suite, the lint script, and the
-    // Dockerfile whose build IS the lint verdict.
-    it.each(["script/check", "script/test", "script/lint", "Dockerfile.lint"])(
-        "reaches %s while counting",
-        (node) => {
-            const key = node.startsWith("script/") ? node : `docker:${node}`;
-            expect([...check.reached]).toContain(key);
-        },
-    );
-
-    // The one that survives is the container's, not the host's: that is the
-    // authoritative verdict, since a successful Dockerfile.lint build is what
-    // CI treats as proof of a clean tree.
-    it("keeps the surviving invocation inside the lint container", () => {
-        expect(walk("docker:Dockerfile.lint").prettier).toBe(1);
-    });
-
-    it("does not reach the host formatting check from make check", () => {
-        expect([...check.reached]).not.toContain("script/fmt-check");
-    });
-});
-
-describe("prettier runs exactly once per CI build", () => {
-    // Rooted at the workflow file, so this is the graph CI executes rather than
-    // the graph someone believed CI executes. `make check` cannot stand in for
-    // it: CI runs script/cibuild, which builds Dockerfile as well as
-    // Dockerfile.lint, and nothing under `make check` ever reads Dockerfile.
-    const ci = walk("workflow:.gitea/workflows/check.yml");
-
-    it("invokes prettier once for the whole CI build", () => {
-        expect(ci.prettier).toBe(1);
-    });
-
-    // script/cibuild is here because the workflow is asserted to run it;
-    // Dockerfile is here because it is the half of the CI graph that the
-    // `make check` walk cannot see.
-    it.each([
-        "script/cibuild",
-        "script/lint",
-        "docker:Dockerfile.lint",
-        "docker:Dockerfile",
-    ])("reaches %s while counting", (node) => {
-        expect([...ci.reached]).toContain(node);
-    });
-
-    // The test and build image must not lint: linting is Dockerfile.lint's job,
-    // and a prettier step added here would be a second pass over the same tree
-    // for the same verdict — on the one path where it matters most.
-    it("keeps prettier out of the test and build image", () => {
-        expect(walk("docker:Dockerfile").prettier).toBe(0);
-    });
-});
-
-describe("the standalone entrypoints still do what their names say", () => {
-    // REPO_POLICIES.md requires both `make lint` and `make fmt-check` to exist
-    // and mean something. Dropping fmt-check from script/check must not turn it
-    // into a target nobody can use, and must not leave `make check` passing
-    // because both halves became no-ops.
-    it("still checks formatting under make fmt-check", () => {
-        expect(walk("make:fmt-check").prettier).toBe(1);
-    });
-
-    it("still checks formatting under make lint", () => {
-        expect(walk("make:lint").prettier).toBe(1);
-    });
-});
-
-describe("script/precommit", () => {
-    // Same duplication as script/check, same fix. The hook still catches a
-    // badly formatted tree before the commit lands, because script/lint is the
-    // container prettier run — that is the whole reason the host call could go.
-    it("checks formatting exactly once", () => {
-        expect(walk("script/precommit").prettier).toBe(1);
-    });
-
-    it("gets that check from the lint container", () => {
-        expect([...walk("script/precommit").reached]).toContain(
-            "docker:Dockerfile.lint",
-        );
-    });
-});
-
-// script/bootstrap installs the dependencies, and it has two install sites: one
-// for the case where yarn has to be reached through nvm, and one for the case
-// where yarn is already on PATH. A substring check against the whole file
-// cannot tell them apart, so it reports the first and says nothing about the
-// second — which is the one the containers take, because the pinned node image
-// ships yarn. Both are resolved separately here.
-const installBranches = (): { withoutYarn: string[]; withYarn: string[] } => {
-    const lines = executable(read("script/bootstrap"));
-    const open = lines.findIndex((line) =>
-        /^install_js_deps\s*\(\)/.test(line),
-    );
-    if (open === -1) {
-        throw new Error("script/bootstrap: no install_js_deps function");
-    }
-    const close = lines.indexOf("}", open);
-    const body = lines.slice(open + 1, close === -1 ? undefined : close);
-    const guard = body.findIndex((line) =>
-        /^if\b.*\bmissing yarn\b/.test(line),
-    );
-    const otherwise = body.indexOf("else", guard);
-    const end = body.indexOf("fi", otherwise);
-    if (guard === -1 || otherwise === -1 || end === -1) {
-        throw new Error(
-            "script/bootstrap: install_js_deps is not the expected " +
-                "if missing yarn / else / fi shape",
-        );
-    }
-    return {
-        withoutYarn: body.slice(guard + 1, otherwise),
-        withYarn: body.slice(otherwise + 1, end),
-    };
-};
-
-// Every `yarn install` in the given lines, with its flags, so an unpinned
-// install cannot hide next to a pinned one.
-const yarnInstalls = (lines: string[]): string[] =>
-    lines.flatMap((line) =>
-        [...line.matchAll(/\byarn install\b[^"'&|;]*/g)].map((match) =>
-            match[0].trim(),
-        ),
-    );
-
-describe("host and container prettier cannot disagree", () => {
-    // With the host pass gone from `make check`, `make fmt-check` is the only
-    // host-side formatting check left, and the container is the gate. The two
-    // must keep producing the same verdict on the same tree, or a developer
-    // running `make fmt-check` gets a green that CI then rejects.
-    //
-    // Three things make them agree, and all three are load-bearing:
-    it("pins the same prettier for both", () => {
-        const pkg = JSON.parse(read("package.json")) as {
-            devDependencies: Record<string, string>;
-        };
-        // An exact version, not a range: `^3.8.1` would let the container and
-        // the host resolve different builds with different formatting.
-        expect(pkg.devDependencies.prettier).toMatch(/^\d+\.\d+\.\d+$/);
-    });
-
-    it("installs from the lockfile on the branch the container takes", () => {
-        // Both images are FROM a node image, which ships yarn, so `missing
-        // yarn` is false and this is the branch that runs in the container.
-        const installs = yarnInstalls(installBranches().withYarn);
-        expect(installs).not.toHaveLength(0);
-        for (const install of installs) {
-            expect(install).toContain("--frozen-lockfile");
-        }
-    });
-
-    it("installs from the lockfile on the nvm branch too", () => {
-        // Not the container's branch, but it is the one a developer without
-        // yarn on PATH gets, and their prettier has to match the container's.
-        const installs = yarnInstalls(installBranches().withoutYarn);
-        expect(installs).not.toHaveLength(0);
-        for (const install of installs) {
-            expect(install).toContain("--frozen-lockfile");
-        }
-    });
-
-    it("runs script/bootstrap inside the lint container", () => {
-        // Without this the lockfile assertions above would be about a script
-        // the container never executes.
-        expect([...walk("docker:Dockerfile.lint").reached]).toContain(
-            "script/bootstrap",
-        );
-    });
-
-    it("keeps .gitignore in the build context", () => {
-        // Prettier 3 reads .gitignore as a default ignore file, so excluding it
-        // from the context would change which files the container checks.
-        const dockerignore = read(".dockerignore")
-            .split("\n")
-            .map((line) => line.trim());
-        expect(dockerignore).not.toContain(".gitignore");
-    });
-});
-
-describe("the walk cannot pass vacuously", () => {
-    // An earlier draft of this file computed a Makefile target as
-    // `node.slice("make:")` — a string where a number belongs, which coerces to
-    // NaN and made every target resolve to nothing. The count went to zero and
-    // an assertion of "not twice" would have been satisfied by a walk that had
-    // read nothing at all. Every way of reaching nothing is therefore an
-    // error here, and the ways are tested rather than assumed.
-    it("reports zero for a subgraph that does not run prettier", () => {
-        expect(walk("make:clean").prettier).toBe(0);
-    });
-
-    it("refuses a Makefile target that does not exist", () => {
-        expect(() => walk("make:no-such-target")).toThrow(
-            /no such Makefile target/,
-        );
-    });
-
-    it("refuses a package.json script that does not exist", () => {
-        expect(() => walk("yarn:no-such-script")).toThrow(
-            /no such package.json script/,
-        );
-    });
-
-    it("refuses a script that does not exist", () => {
-        expect(() => walk("script/no-such-script")).toThrow(/ENOENT/);
-    });
-
-    it("refuses a node that resolves to no commands", () => {
-        // .dockerignore has no RUN steps, standing in for a Dockerfile whose
-        // steps a restructure moved somewhere the resolver cannot see.
-        expect(() => walk("docker:.dockerignore")).toThrow(
-            /resolved to no commands/,
-        );
-    });
-
-    it("refuses a node kind it does not understand", () => {
-        expect(() => walk("nonsense")).toThrow(/unresolvable node/);
-    });
-
-    it("refuses to walk in circles", () => {
-        expect(() => walk("make:check", ["script/check"])).toThrow(
-            /invocation cycle/,
-        );
-    });
-});
-
-describe("the resolver reads what the shell would run", () => {
-    // Counting per line is how `yarn run prettier --check . && yarn run
-    // prettier --check src` read as a single invocation.
-    it("counts every prettier invocation on a line", () => {
-        expect(
-            countPrettier(
-                "yarn run prettier --check . && yarn run prettier --check src",
-            ),
-        ).toBe(2);
-    });
-
-    it("does not count the config files as invocations", () => {
-        expect(countPrettier("COPY .prettierrc .prettierignore ./")).toBe(0);
-    });
-
-    // The counting `continue` also dropped every edge that shared a line with a
-    // prettier call, so a whole subtree could be hidden behind one `&&`.
-    it("still follows the edges of a line that invokes prettier", () => {
-        expect(
-            edgesOf('yarn run prettier --check . && "$SCRIPT_DIR/lint"'),
-        ).toContain("script/lint");
-    });
-
-    it("resolves every spelling of a script call to one node", () => {
-        expect(
-            edgesOf('"$SCRIPT_DIR/lint" "${SCRIPT_DIR}/test" script/fmt'),
-        ).toEqual(["script/lint", "script/test", "script/fmt"]);
-    });
-
-    it("follows a bare docker build to Dockerfile and -f to its file", () => {
-        expect(edgesOf("docker build .")).toContain("docker:Dockerfile");
-        expect(edgesOf("docker build -f Dockerfile.lint .")).toContain(
-            "docker:Dockerfile.lint",
-        );
-    });
-
-    it("reads the run steps of the CI workflow and not its uses steps", () => {
-        expect(commandsOf("workflow:.gitea/workflows/check.yml")).toEqual([
-            "script/cibuild",
-        ]);
-    });
-});

test/packaging/nested-checkout.test.ts

@@ -0,0 +1,50 @@
+// A checkout nested under `.claude/` must not add its tests to this suite.
+// The test plants one in a temporary directory next to a real test file and
+// asks vitest, with this repo's config, which test files it would run.
+import { afterEach, describe, expect, it } from "vitest";
+import { execFileSync } from "node:child_process";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = fileURLToPath(new URL("../../", import.meta.url));
+
+let root = "";
+
+afterEach(() => {
+    rmSync(root, { recursive: true, force: true });
+});
+
+const writeTest = (path: string): void => {
+    mkdirSync(join(root, path, ".."), { recursive: true });
+    writeFileSync(
+        join(root, path),
+        'import { it } from "vitest";\nit("runs", () => {});\n',
+    );
+};
+
+describe("vitest.config.ts", () => {
+    it("does not collect tests from a checkout nested under .claude/", () => {
+        root = mkdtempSync(join(tmpdir(), "quak-nested-checkout-"));
+        writeTest("test/real.test.ts");
+        writeTest(".claude/worktrees/other/test/real.test.ts");
+
+        const output = execFileSync(
+            process.execPath,
+            [
+                join(repoRoot, "node_modules/vitest/vitest.mjs"),
+                "list",
+                "--filesOnly",
+                "--config",
+                join(repoRoot, "vitest.config.ts"),
+                "--root",
+                root,
+            ],
+            { cwd: root, encoding: "utf-8" },
+        );
+
+        const files = output.split("\n").filter((line) => line !== "");
+        expect(files).toEqual(["test/real.test.ts"]);
+    });
+});

test/retry/retry.test.ts

@@ -149,8 +149,11 @@ describe("isRetryable: transport failures", () => {
     });
 
     it("retries an errno carried on the error itself", () => {
+        // Every errno the classifier names, so none can be reclassified
+        // unnoticed.
         for (const code of [
             "ECONNRESET",
+            "ECONNABORTED",
             "ETIMEDOUT",
             "EPIPE",
             "ENOTFOUND",
@@ -158,6 +161,8 @@ describe("isRetryable: transport failures", () => {
             "ECONNREFUSED",
             "EHOSTUNREACH",
             "ENETUNREACH",
+            "ENETRESET",
+            "ENETDOWN",
         ]) {
             expect(isRetryable(errnoError(code))).toBe(true);
         }
@@ -215,6 +220,27 @@ describe("isRetryable: transport failures", () => {
         looped.cause = looped;
         expect(isRetryable(looped)).toBe(false);
     });
+
+    it("terminates on a cause chain that loops through two errors", () => {
+        const first: Error & { cause?: unknown } = new Error("first");
+        const second = new Error("second", { cause: first });
+        first.cause = second;
+        expect(isRetryable(first)).toBe(false);
+    });
+
+    it("reads the error and at most seven causes below it", () => {
+        // The walk is bounded at eight links. An errno at the eighth link is
+        // found; one at the ninth is not.
+        const buried = (causes: number): Error => {
+            let err = errnoError("ECONNRESET");
+            for (let i = 0; i < causes; i++) {
+                err = new Error(`wrapper ${i}`, { cause: err });
+            }
+            return err;
+        };
+        expect(isRetryable(buried(7))).toBe(true);
+        expect(isRetryable(buried(8))).toBe(false);
+    });
 });
 
 describe("isRetryable: stream truncation versus corruption", () => {
@@ -279,10 +305,9 @@ describe("isSafeToReplay", () => {
      * that is not the whole question: the other half is "could the first
      * attempt already have taken effect on the server?".
      *
-     * quak's non-idempotent calls are `/users/srp/create-session`,
-     * `/users/two-factor/verify` (which consumes one of a limited number of
-     * 2FA attempts) and `/files/thumbnail`. A blind replay of any of them can
-     * do real damage, so they retry only on the failures that establish no TCP
+     * The calls this guards are the `POST` and `PUT` requests listed in the
+     * README under "Endpoints used". A blind replay of some of them can do
+     * real damage, so they retry only on the failures that establish no TCP
      * connection to the server ever existed — DNS produced no address, or the
      * peer refused the connection — and therefore that no request byte can
      * have been transmitted.
@@ -333,6 +358,52 @@ describe("isSafeToReplay", () => {
         ).toBe(false);
         expect(isSafeToReplay(new TypeError("fetch failed"))).toBe(false);
     });
+
+    it("does not replay any other errno the classifier names", () => {
+        for (const code of [
+            "ECONNRESET",
+            "ECONNABORTED",
+            "ETIMEDOUT",
+            "EPIPE",
+            "EHOSTUNREACH",
+            "ENETUNREACH",
+            "ENETRESET",
+            "ENETDOWN",
+        ]) {
+            expect(isSafeToReplay(errnoError(code))).toBe(false);
+        }
+    });
+
+    it("does not replay a chain that also shows the request may have gone out", () => {
+        // A connect errno somewhere in the chain is not enough: any other
+        // errno beside it is doubt, and doubt is not replayed.
+        const reset = Object.assign(
+            new Error("read ECONNRESET", { cause: errnoError("ECONNREFUSED") }),
+            { code: "ECONNRESET" },
+        );
+        const mixed = new TypeError("fetch failed", { cause: reset });
+        expect(isRetryable(mixed)).toBe(true);
+        expect(isSafeToReplay(mixed)).toBe(false);
+    });
+
+    it("does not replay a chain longer than the walk reads", () => {
+        // Eight connect errnos, then a reset at the ninth link, below the
+        // limit. The walk never sees the reset, so it cannot rule it out.
+        const refusedChain = (below: Error | undefined): Error => {
+            let err = below;
+            for (let i = 0; i < 8; i++) {
+                err = Object.assign(new Error(`refused ${i}`, { cause: err }), {
+                    code: "ECONNREFUSED",
+                });
+            }
+            return err as Error;
+        };
+        expect(isSafeToReplay(refusedChain(errnoError("ECONNRESET")))).toBe(
+            false,
+        );
+        // The same eight links with nothing below them are replayable.
+        expect(isSafeToReplay(refusedChain(undefined))).toBe(true);
+    });
 });
 
 // ---------------------------------------------------------------------------

test/smoke.test.ts

@@ -1,9 +1,43 @@
-import { describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { readFileSync } from "node:fs";
 import { VERSION } from "../src/index.js";
 
-describe("quak", () => {
-    it("exports a version string", () => {
-        expect(typeof VERSION).toBe("string");
-        expect(VERSION.length).toBeGreaterThan(0);
+const packageVersion = (
+    JSON.parse(
+        readFileSync(new URL("../package.json", import.meta.url), "utf-8"),
+    ) as { version: string }
+).version;
+
+class ExitCalled extends Error {}
+
+describe("version", () => {
+    const argv = process.argv;
+
+    afterEach(() => {
+        process.argv = argv;
+        vi.restoreAllMocks();
+    });
+
+    it("exports the version from package.json", () => {
+        expect(VERSION).toBe(packageVersion);
+    });
+
+    // Runs bin/quak.ts with --version. commander prints the version and then
+    // calls process.exit, which is stubbed to throw so the test survives.
+    it("reports the version from package.json in quak --version", async () => {
+        const printed: string[] = [];
+        vi.spyOn(process.stdout, "write").mockImplementation((chunk) => {
+            printed.push(String(chunk));
+            return true;
+        });
+        vi.spyOn(process, "exit").mockImplementation(() => {
+            throw new ExitCalled();
+        });
+        process.argv = ["node", "quak", "--version"];
+
+        await expect(import("../bin/quak.js")).rejects.toBeInstanceOf(
+            ExitCalled,
+        );
+        expect(printed.join("").trim()).toBe(packageVersion);
     });
 });

test/thumbnails/thumbnails.test.ts

@@ -215,6 +215,9 @@ const buildThumbMock = async (opts?: {
             thumbnail: {
                 decryptionHeader: toBase64(sodium.randombytes_buf(24)),
             },
+            // The encrypted size of the thumbnail the server records; large
+            // enough here that the default encoding fits.
+            info: { thumbSize: 1_000_000 },
             updationTime: TEST_TIME,
         };
     };
@@ -446,6 +449,32 @@ const openLib = (client: Client): Promise<Library> =>
         precacheOriginals: false,
     });
 
+/** The mock's raw record for one file, for a test to change before login. */
+const rawFile = (m: ThumbMockState, fileID: number): Record<string, unknown> =>
+    m.filesByCollection[1]!.find((f) => f.id === fileID)!;
+
+/** Replace the original the mock serves for one file. */
+const replaceOriginal = (
+    m: ThumbMockState,
+    fileID: number,
+    body: Uint8Array,
+): void => {
+    const push = sodium.crypto_secretstream_xchacha20poly1305_init_push(
+        m.fileKeys[fileID]!,
+    );
+    m.fileCiphertexts[fileID] =
+        sodium.crypto_secretstream_xchacha20poly1305_push(
+            push.state,
+            body,
+            null,
+            sodium.crypto_secretstream_xchacha20poly1305_TAG_FINAL,
+        );
+    rawFile(m, fileID).file = { decryptionHeader: toBase64(push.header) };
+};
+
+const isOriginalDownload = (url: string): boolean =>
+    url.includes("files.ente.io") || url.includes("/files/download/");
+
 const login = (fetch: typeof globalThis.fetch, retry?: RetryOptions) =>
     Client.login({
         email: TEST_EMAIL,
@@ -581,6 +610,33 @@ describe("listMissingThumbnails", () => {
         // Should still be 2, not 4 (each file checked only once)
         expect(missing.length).toBe(2);
     });
+
+    it("skips a file another account owns without fetching its thumbnail", async () => {
+        const otherMock = await buildThumbMock();
+        rawFile(otherMock, 102).ownerID = 7;
+        const logs: string[] = [];
+        const counted = countingFetch(
+            buildThumbFetch(otherMock),
+            (url) => url.includes("thumbnails.ente.io") && url.includes("102"),
+        );
+        const client = await login(counted.fetch);
+        const lib = await openLib(client);
+
+        const missing = await listMissingThumbnails(lib, client, (msg) =>
+            logs.push(msg),
+        );
+        lib.close();
+
+        expect(missing.map((m) => m.fileID)).toEqual([101]);
+        expect(counted.matched()).toBe(0);
+        expect(
+            logs.some(
+                (l) =>
+                    l.includes("Skipping file-102.jpg") &&
+                    l.includes("another account"),
+            ),
+        ).toBe(true);
+    });
 });
 
 describe("fixMissingThumbnails", () => {
@@ -688,6 +744,93 @@ describe("fixMissingThumbnails", () => {
         expect(fixMock.uploadedThumbnails.length).toBe(1);
         expect(fixMock.uploadedThumbnails[0]!.fileID).toBe(101);
     });
+
+    it("skips a file another account owns without downloading it", async () => {
+        // The server accepts a thumbnail only from the file's owner.
+        const fixMock = await buildThumbMock();
+        rawFile(fixMock, 101).ownerID = 7;
+        const counted = countingFetch(
+            buildThumbFetch(fixMock),
+            isOriginalDownload,
+        );
+        const client = await login(counted.fetch);
+        const lib = await openLib(client);
+
+        const results = await fixMissingThumbnails(lib, client, [101]);
+        lib.close();
+
+        expect(results[0]!.status).toBe("skipped");
+        expect(results[0]!.reason).toContain("another account");
+        expect(counted.matched()).toBe(0);
+        expect(fixMock.uploadedThumbnails.length).toBe(0);
+    });
+
+    it("skips a file whose recorded thumbnail size is 0 without downloading it", async () => {
+        // The server refuses a thumbnail larger than the one it records, and
+        // no thumbnail is 0 bytes.
+        const fixMock = await buildThumbMock();
+        rawFile(fixMock, 101).info = { thumbSize: 0 };
+        const counted = countingFetch(
+            buildThumbFetch(fixMock),
+            isOriginalDownload,
+        );
+        const client = await login(counted.fetch);
+        const lib = await openLib(client);
+
+        const results = await fixMissingThumbnails(lib, client, [101]);
+        lib.close();
+
+        expect(results[0]!.status).toBe("skipped");
+        expect(results[0]!.reason).toContain("recorded thumbnail size is 0");
+        expect(counted.matched()).toBe(0);
+        expect(fixMock.uploadedThumbnails.length).toBe(0);
+    });
+
+    it("re-encodes smaller until the thumbnail fits the recorded size", async () => {
+        // A noisy 400x300 JPEG, which the default encoding (quality 50, not
+        // resized because it is under 720 px) cannot compress below the size
+        // recorded here: one byte less than that encoding's ciphertext.
+        const fixMock = await buildThumbMock();
+        const w = 400;
+        const h = 300;
+        const noisy = new Uint8Array(
+            jpegJs.encode(
+                {
+                    data: sodium.randombytes_buf(w * h * 4),
+                    width: w,
+                    height: h,
+                },
+                90,
+            ).data,
+        );
+        replaceOriginal(fixMock, 101, noisy);
+        const decoded = jpegJs.decode(noisy, {
+            useTArray: true,
+            formatAsRGBA: true,
+        });
+        const defaultSize =
+            jpegJs.encode(decoded, 50).data.length +
+            sodium.crypto_secretstream_xchacha20poly1305_ABYTES;
+        const recordedSize = defaultSize - 1;
+        rawFile(fixMock, 101).info = { thumbSize: recordedSize };
+
+        const client = await login(buildThumbFetch(fixMock));
+        const lib = await openLib(client);
+
+        const results = await fixMissingThumbnails(lib, client, [101]);
+        lib.close();
+
+        expect(results[0]!.status).toBe("fixed");
+        const upload = fixMock.uploadedThumbnails[0]!;
+        expect(upload.ciphertext.length).toBeLessThanOrEqual(recordedSize);
+        const decrypted = decryptBlob(
+            upload.ciphertext,
+            fromBase64(upload.decryptionHeader),
+            fixMock.fileKeys[101]!,
+        );
+        expect(decrypted[0]).toBe(0xff);
+        expect(decrypted[1]).toBe(0xd8);
+    });
 });
 
 describe("Client.getApiClient", () => {

vitest.config.ts

@@ -0,0 +1,10 @@
+import { configDefaults, defineConfig } from "vitest/config";
+
+// vitest does not read .gitignore when looking for tests. A checkout nested
+// under .claude/ has its own test/ tree, and without this exclude the suite
+// runs once per nested checkout and still reports success.
+export default defineConfig({
+    test: {
+        exclude: [...configDefaults.exclude, ".claude/**"],
+    },
+});

yarn.lock

@@ -528,13 +528,6 @@
   resolved "https://registry.yarnpkg.com/@types/json-schema/-/json-schema-7.0.15.tgz#596a1747233694d50f6ad8a7869fcb6f56cf5841"
   integrity sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==
 
-"@types/libsodium-wrappers-sumo@0.8.2":
-  version "0.8.2"
-  resolved "https://registry.yarnpkg.com/@types/libsodium-wrappers-sumo/-/libsodium-wrappers-sumo-0.8.2.tgz#488e8747fbb982fe901020b5afeaddfa63da6830"
-  integrity sha512-uFOBpg/r21hExVlh2ty8YpDfSR+Yy3Jn8XS4+SSjitbhTxdYq+pBz/49XRxyUFe8SzqujHf/Wu0/O4d+FUtNfQ==
-  dependencies:
-    libsodium-wrappers-sumo "*"
-
 "@types/node@22.18.13":
   version "22.18.13"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-22.18.13.tgz#a037c4f474b860be660e05dbe92a9ef945472e28"
@@ -1076,6 +1069,11 @@ fastq@^1.6.0:
   dependencies:
     reusify "^1.0.4"
 
+fflate@0.8.3:
+  version "0.8.3"
+  resolved "https://registry.yarnpkg.com/fflate/-/fflate-0.8.3.tgz#bc27d8eb30343d4d512abb03480202ce65d825fc"
+  integrity sha512-tbZNuJrLwGUp3zshBtdy4W+ORxZuIh8a5ilyIEQDC5rY1f3U20JMry0Ll3WBzU58EZKsEuJFXhb5gwv8CsPvgA==
+
 file-entry-cache@^8.0.0:
   version "8.0.0"
   resolved "https://registry.yarnpkg.com/file-entry-cache/-/file-entry-cache-8.0.0.tgz#7787bddcf1131bffb92636c69457bbc0edd6d81f"
@@ -1249,7 +1247,7 @@ libsodium-sumo@^0.8.0:
   resolved "https://registry.yarnpkg.com/libsodium-sumo/-/libsodium-sumo-0.8.4.tgz#6d4687781fa0ad398af14a7df872d5c27cf8cd31"
   integrity sha512-TMtHShQfVVsaxDygyapvUC3o7YsPgXa/hRWeIgzyFz6w5k/1hirGptCxp1U7XwW3rCskaTTYKgV10v86UiGgNw==
 
-libsodium-wrappers-sumo@*, libsodium-wrappers-sumo@0.8.4:
+libsodium-wrappers-sumo@0.8.4:
   version "0.8.4"
   resolved "https://registry.yarnpkg.com/libsodium-wrappers-sumo/-/libsodium-wrappers-sumo-0.8.4.tgz#6656a3e7e0551ecce08ddee4bfb501a092eac6fa"
   integrity sha512-ql7hcgulKZ3ekfa2DGAogcCKsWU0diA/0nArz1CFzh93WQdb46/Kj18ka/Hifq6uA3Ush34Pc6vU/6HXeRwUkg==