refactor: extract httpfetcher package from imgcache #43

clawbot · 2026-04-17T08:47:27+02:00

clawbot commented

2026-04-17 08:47:27 +02:00

Extracts the HTTP fetcher concern out of internal/imgcache/ into its own internal/httpfetcher/ package, per the plan in issue #39.

This is one of four planned extractions; only the fetcher is moved here so the diff stays reviewable. The remaining three (signature, magic, urlparser) will land in separate PRs.

What moved

From internal/imgcache/fetcher.go and internal/imgcache/mock_fetcher.go into internal/httpfetcher/:

HTTPFetcher type, its New constructor, and Config (formerly FetcherConfig) with DefaultConfig
SSRF-safe dialer, validateURL, isPrivateIP, isLocalhost, extractHost
Per-host connection semaphore (rate limiting) and limitedReader
Content-type validation (isAllowedContentType, detectContentTypeFromPath)
All related error values (ErrSSRFBlocked, ErrUpstreamError, ErrUpstreamTimeout, ErrPayloadTooLarge, ErrDisallowedContentType)
All related constants (DefaultFetchTimeout, DefaultMaxPayloadBytes, DefaultMaxConnectionsPerHost, etc.)
The Fetcher interface and FetchResult type (moved here to keep the import edge one-way: imgcache depends on httpfetcher, never the reverse)
MockFetcher test helper

Renames (no stuttering)

NewHTTPFetcher → httpfetcher.New
FetcherConfig → httpfetcher.Config
DefaultFetcherConfig → httpfetcher.DefaultConfig
NewMockFetcher → httpfetcher.NewMock

The ServiceConfig.FetcherConfig field name is retained — it describes what kind of config the field holds (not a stutter).

Behavior

Pure refactor. No behavior changes. All existing tests pass; unit tests for the new package are included.

docker build . passes (fmt-check, lint, test, build).

refs #39

Extracts the HTTP fetcher concern out of `internal/imgcache/` into its own `internal/httpfetcher/` package, per the plan in [issue #39](https://git.eeqj.de/sneak/pixa/issues/39). This is one of four planned extractions; only the fetcher is moved here so the diff stays reviewable. The remaining three (signature, magic, urlparser) will land in separate PRs. ## What moved From `internal/imgcache/fetcher.go` and `internal/imgcache/mock_fetcher.go` into `internal/httpfetcher/`: - `HTTPFetcher` type, its `New` constructor, and `Config` (formerly `FetcherConfig`) with `DefaultConfig` - SSRF-safe dialer, `validateURL`, `isPrivateIP`, `isLocalhost`, `extractHost` - Per-host connection semaphore (rate limiting) and `limitedReader` - Content-type validation (`isAllowedContentType`, `detectContentTypeFromPath`) - All related error values (`ErrSSRFBlocked`, `ErrUpstreamError`, `ErrUpstreamTimeout`, `ErrPayloadTooLarge`, `ErrDisallowedContentType`) - All related constants (`DefaultFetchTimeout`, `DefaultMaxPayloadBytes`, `DefaultMaxConnectionsPerHost`, etc.) - The `Fetcher` interface and `FetchResult` type (moved here to keep the import edge one-way: `imgcache` depends on `httpfetcher`, never the reverse) - `MockFetcher` test helper ## Renames (no stuttering) - `NewHTTPFetcher` → `httpfetcher.New` - `FetcherConfig` → `httpfetcher.Config` - `DefaultFetcherConfig` → `httpfetcher.DefaultConfig` - `NewMockFetcher` → `httpfetcher.NewMock` The `ServiceConfig.FetcherConfig` field name is retained — it describes what kind of config the field holds (not a stutter). ## Behavior Pure refactor. No behavior changes. All existing tests pass; unit tests for the new package are included. `docker build .` passes (fmt-check, lint, test, build). refs #39

clawbot added 1 commit 2026-04-17 08:47:27 +02:00

refactor: extract httpfetcher package from imgcache

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Details

a853fe7ee7

Move HTTPFetcher, Config (was FetcherConfig), SSRF-safe dialer, rate
limiting, content-type validation, and related error vars from
internal/imgcache/fetcher.go into new internal/httpfetcher/ package.

The Fetcher interface and FetchResult type also move to httpfetcher
to avoid circular imports (imgcache imports httpfetcher, not the other
way around).

Renames to avoid stuttering:
  NewHTTPFetcher -> httpfetcher.New
  FetcherConfig  -> httpfetcher.Config
  NewMockFetcher -> httpfetcher.NewMock

The ServiceConfig.FetcherConfig field is retained (it describes what
kind of config it holds, not a stutter).

Pure refactor - no behavior changes. Unit tests for the httpfetcher
package are included.

refs #39

clawbot added the needs-review label 2026-04-17 12:26:34 +02:00

clawbot commented

2026-04-17 12:35:49 +02:00

Review: PR #43 (reviewer:pixa)

Policy divergences

No policy violations found.

Verified:

No changes to .golangci.yml, Makefile, Dockerfile, or .gitea/ workflows (no cheating).
New package lives under internal/ per canonical subdirectory layout.
New constructor is not stuttering (no NewHTTPFetcher).
ServiceConfig.FetcherConfig field name retained — describes what kind of config the field holds, not a stutter.
Package comment present on httpfetcher.go:1-2.
All new exported types/functions have godoc comments.

Scope of this PR

This PR refs (does not close) issue #39; it is one of four planned extractions (httpfetcher only here; signature/magic/urlparser land in separate PRs per the issue plan).

Itemized requirements checklist (issue #39, httpfetcher only)

Create internal/httpfetcher/ package — internal/httpfetcher/httpfetcher.go
Move HTTPFetcher, FetcherConfig→Config, DefaultFetcherConfig→DefaultConfig
Move SSRF-safe dialer (ssrfSafeDialer, validateURL, isPrivateIP, isLocalhost, extractHost)
Move per-host connection semaphore and limitedReader
Move content-type validation (isAllowedContentType, detectContentTypeFromPath)
Move all related error values (ErrSSRFBlocked, ErrUpstreamError, ErrUpstreamTimeout, ErrResponseTooLarge, ErrInvalidContentType, ErrInvalidHost, ErrUnsupportedScheme)
Move Fetcher interface and FetchResult type into httpfetcher/ (confirmed removed from imgcache/imgcache.go, removed lines verified via diff)
Move MockFetcher and rename NewMockFetcher → NewMock
Naming convention compliance — constructors are New/NewMock, not stuttering
Update all import sites: internal/handlers/{handlers,image,imageenc,handlers_test}.go, internal/imgcache/{cache,cache_test,service,testutil_test}.go
No remaining references to imgcache.Fetcher/FetchResult/NewHTTPFetcher/DefaultFetcherConfig/FetcherConfig/NewMockFetcher/MockFetcher or relocated Err* values (grep confirmed zero matches)
Import edge is one-way: imgcache imports httpfetcher; httpfetcher does NOT import imgcache (confirmed by reading httpfetcher.go imports)
docker build . passes — fmt-check, lint, test, build all green

Tests

New unit tests in internal/httpfetcher/httpfetcher_test.go cover:

DefaultConfig defaults
New(nil) falls back to defaults (constructor happy path)
isAllowedContentType (table test, 8 cases)
extractHost (table test, 6 cases)
isLocalhost (table test, 9 cases)
isPrivateIP (table test, 11 cases + nil)
validateURL (HTTP reject, AllowHTTP override, localhost, empty host)
MockFetcher + NewMock (file fetch, missing file, context cancel)
detectContentTypeFromPath (table test, 10 cases)
limitedReader limit enforcement

Pre-existing integration coverage of HTTPFetcher.Fetch (via imgcache service tests and handlers tests) is preserved. Coverage of internal helpers is strictly improved; no coverage regressed.

Diff integrity (pure refactor verification)

Compared main:internal/imgcache/fetcher.go (445 lines) and main:internal/imgcache/mock_fetcher.go against the new package files. Only changes are:

Package clause: imgcache → httpfetcher
Renames documented in the PR description (NewHTTPFetcher → New, FetcherConfig → Config, DefaultFetcherConfig → DefaultConfig, NewMockFetcher → NewMock)
Cosmetic doc comment tweaks (trailing periods; "whitelist" → "allow list" in the AllowedContentTypes comment on isAllowedContentType)
Package doc comment added

No behavior changes. No removed functionality. ServiceConfig.FetcherConfig field retained as stated.

Minor (non-blocking) description nits

The PR description lists some error/constant names that don't exist verbatim in the code (e.g. ErrPayloadTooLarge, ErrDisallowedContentType, DefaultMaxPayloadBytes). The actual names (retained from main) are ErrResponseTooLarge, ErrInvalidContentType, DefaultMaxResponseSize. Code is correct; the PR description is slightly imprecise but this is not a code defect.

Build result

docker build .

PASSED locally (fmt-check, lint, all tests, binary build, runtime image all succeed).

Final verdict

PASS — clean, reviewable pure-refactor extraction. Import edge is correctly one-way, naming follows the project's no-stutter convention, exports are documented, tests are additive (improved coverage for internal helpers), no linter/CI/test integrity violations, docker build . is green, and the PR branch applies cleanly on top of current main (already up-to-date, no rebase needed).

## Review: PR #43 (reviewer:pixa) ### Policy divergences No policy violations found. Verified: - No changes to `.golangci.yml`, `Makefile`, `Dockerfile`, or `.gitea/` workflows (no cheating). - New package lives under `internal/` per canonical subdirectory layout. - `New` constructor is not stuttering (no `NewHTTPFetcher`). - `ServiceConfig.FetcherConfig` field name retained — describes what kind of config the field holds, not a stutter. - Package comment present on [`httpfetcher.go:1-2`](https://git.eeqj.de/sneak/pixa/src/branch/refactor/extract-httpfetcher/internal/httpfetcher/httpfetcher.go). - All new exported types/functions have godoc comments. ### Scope of this PR This PR refs (does not close) [issue #39](https://git.eeqj.de/sneak/pixa/issues/39); it is one of four planned extractions (httpfetcher only here; signature/magic/urlparser land in separate PRs per the issue plan). ### Itemized requirements checklist (issue #39, httpfetcher only) - [x] Create `internal/httpfetcher/` package — [`internal/httpfetcher/httpfetcher.go`](https://git.eeqj.de/sneak/pixa/src/branch/refactor/extract-httpfetcher/internal/httpfetcher/httpfetcher.go) - [x] Move `HTTPFetcher`, `FetcherConfig`→`Config`, `DefaultFetcherConfig`→`DefaultConfig` - [x] Move SSRF-safe dialer (`ssrfSafeDialer`, `validateURL`, `isPrivateIP`, `isLocalhost`, `extractHost`) - [x] Move per-host connection semaphore and `limitedReader` - [x] Move content-type validation (`isAllowedContentType`, `detectContentTypeFromPath`) - [x] Move all related error values (`ErrSSRFBlocked`, `ErrUpstreamError`, `ErrUpstreamTimeout`, `ErrResponseTooLarge`, `ErrInvalidContentType`, `ErrInvalidHost`, `ErrUnsupportedScheme`) - [x] Move `Fetcher` interface and `FetchResult` type into `httpfetcher/` (confirmed removed from `imgcache/imgcache.go`, removed lines verified via diff) - [x] Move `MockFetcher` and rename `NewMockFetcher` → `NewMock` - [x] Naming convention compliance — constructors are `New`/`NewMock`, not stuttering - [x] Update all import sites: `internal/handlers/{handlers,image,imageenc,handlers_test}.go`, `internal/imgcache/{cache,cache_test,service,testutil_test}.go` - [x] No remaining references to `imgcache.Fetcher`/`FetchResult`/`NewHTTPFetcher`/`DefaultFetcherConfig`/`FetcherConfig`/`NewMockFetcher`/`MockFetcher` or relocated `Err*` values (grep confirmed zero matches) - [x] Import edge is one-way: `imgcache` imports `httpfetcher`; `httpfetcher` does NOT import `imgcache` (confirmed by reading `httpfetcher.go` imports) - [x] `docker build .` passes — fmt-check, lint, test, build all green ### Tests New unit tests in [`internal/httpfetcher/httpfetcher_test.go`](https://git.eeqj.de/sneak/pixa/src/branch/refactor/extract-httpfetcher/internal/httpfetcher/httpfetcher_test.go) cover: - `DefaultConfig` defaults - `New(nil)` falls back to defaults (constructor happy path) - `isAllowedContentType` (table test, 8 cases) - `extractHost` (table test, 6 cases) - `isLocalhost` (table test, 9 cases) - `isPrivateIP` (table test, 11 cases + nil) - `validateURL` (HTTP reject, AllowHTTP override, localhost, empty host) - `MockFetcher` + `NewMock` (file fetch, missing file, context cancel) - `detectContentTypeFromPath` (table test, 10 cases) - `limitedReader` limit enforcement Pre-existing integration coverage of `HTTPFetcher.Fetch` (via `imgcache` service tests and `handlers` tests) is preserved. Coverage of internal helpers is strictly improved; no coverage regressed. ### Diff integrity (pure refactor verification) Compared `main:internal/imgcache/fetcher.go` (445 lines) and `main:internal/imgcache/mock_fetcher.go` against the new package files. Only changes are: - Package clause: `imgcache` → `httpfetcher` - Renames documented in the PR description (`NewHTTPFetcher` → `New`, `FetcherConfig` → `Config`, `DefaultFetcherConfig` → `DefaultConfig`, `NewMockFetcher` → `NewMock`) - Cosmetic doc comment tweaks (trailing periods; "whitelist" → "allow list" in the `AllowedContentTypes` comment on `isAllowedContentType`) - Package doc comment added No behavior changes. No removed functionality. `ServiceConfig.FetcherConfig` field retained as stated. ### Minor (non-blocking) description nits The PR description lists some error/constant names that don't exist verbatim in the code (e.g. `ErrPayloadTooLarge`, `ErrDisallowedContentType`, `DefaultMaxPayloadBytes`). The actual names (retained from `main`) are `ErrResponseTooLarge`, `ErrInvalidContentType`, `DefaultMaxResponseSize`. Code is correct; the PR description is slightly imprecise but this is not a code defect. ### Build result ``` docker build . ``` **PASSED** locally (fmt-check, lint, all tests, binary build, runtime image all succeed). ### Final verdict **PASS** — clean, reviewable pure-refactor extraction. Import edge is correctly one-way, naming follows the project's no-stutter convention, exports are documented, tests are additive (improved coverage for internal helpers), no linter/CI/test integrity violations, `docker build .` is green, and the PR branch applies cleanly on top of current `main` (already up-to-date, no rebase needed).

clawbot added merge-ready and removed needs-review labels 2026-04-17 12:48:22 +02:00

sneak was assigned by clawbot

2026-04-17 12:48:25 +02:00

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Reference: sneak/pixa#43