test: wait until the page shows a screen, not only until it lays out (closes #502)

The browser suites' wait for a screen passed as soon as the element laid
out. Until the page's stylesheet has applied, every view lays out, so an
approval test could read the prompt before the page's script had filled
it. visible() in the Chrome harness and waitVisible() in the Firefox
driver now also wait for the page to finish loading and for neither the
element nor anything around it to carry the hidden class that showView()
keeps on every view but the current one. Both also require the element's
computed visibility to be visible, as the browser library's own check in
Chrome did. No caller changed.

Model: opus-5-5

README.md

@@ -339,7 +339,9 @@ There are two suites, one per browser, and they share no code. Chrome runs on
 Playwright; Firefox has its own WebDriver client, because Playwright cannot
 observe errors on a Firefox extension page at all — see
 [Firefox](#firefox-make-test-e2e-firefox) below. Both require docker, and both
-are outside `make check`.
+are outside `make check`. Neither opens the popup from the toolbar button: both
+load its page in an ordinary tab, so what the toolbar popup itself adds, its
+size and its closing when it loses focus, is covered by neither.
 
 ### Chrome (`make test-e2e`)
 
@@ -412,27 +414,52 @@ content script, the inpage provider, the background worker and the approval
 popup all have to work together. A local test page is served by the route
 handler on a reserved-TLD origin, gets `window.ethereum` from the shipped
 `MAIN`-world content script like any other page, and drives
-`eth_requestAccounts`, `personal_sign`, `eth_signTypedData_v4` and
+`eth_requestAccounts`, `personal_sign`, `eth_signTypedData_v4`,
-`eth_sendTransaction` through the real prompts. Every signature is recovered in
+`eth_sendTransaction` and `wallet_switchEthereumChain` through the real prompts.
-the runner and compared against the active address, the transaction assertions
+Every signature is recovered in the runner and compared against the active
-run against the raw signed transaction captured at `eth_sendRawTransaction`
+address, the transaction assertions run against the raw signed transaction
-rather than against anything the extension reported, rejecting each prompt is
+captured at `eth_sendRawTransaction` rather than against anything the extension
-required to return a rejection to the page rather than hang or resolve, a prompt
+reported, rejecting each prompt is required to return a rejection to the page
-raised while another approval window has focus is required to open a window of
+rather than hang or resolve, a network switch request is required to leave the
-its own, and the password is required to be absent from every message the
+stored network unchanged and send no `chainChanged` until it is approved, a
-approval window sends to the background — with the message that would carry it
+network switch in Settings is required to send the page `chainChanged` with the
-required to be present, so that check cannot pass by observing nothing. That
+new chain id, a prompt raised while another approval window has focus is
-last one is the standing floor under
+required to open a window of its own, and the password is required to be absent
+from every message the approval window sends to the background — with the
+message that would carry it required to be present, so that check cannot pass by
+observing nothing. That last one is the standing floor under
 [#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
 
-Two limits of that coverage, neither of them papered over. The RPC is stubbed
+The limits of that coverage and of the rest of the Chrome suite, none of them
-throughout, so this is **not** a real dApp against a real network with real
+papered over:
-funds; that remains a human pass before 1.0.0. The site-connection prompt is
+
-raised through `chrome.action.openPopup()`, and headless Chromium's
+- The RPC is stubbed throughout, so this is **not** a real dApp against a real
-browser-action popup is not a page Playwright can see or click, so that one
+  network with real funds; that remains a human pass before 1.0.0.
-prompt is driven at the URL the extension itself puts on the action — the same
+- The site-connection prompt is raised through `chrome.action.openPopup()`, and
-page and the same approval id, but whether a real toolbar click shows it is not
+  headless Chromium's browser-action popup is not a page Playwright can see or
-observable here.
+  click, so that one prompt is driven at the URL the extension itself puts on
+  the action — the same page and the same approval id, but whether a real
+  toolbar click shows it is not observable here.
+- Each site-connection request is made 1.5 seconds after the tab it will be
+  driven in is opened (`APPROVAL_TAB_SETTLE_MS` in `tests/e2e/run.js`), because
+  opening that tab closes the previous prompt's toolbar popup; a request made
+  just after that popup closes is not covered.
+- In the tests that approve a signature or a transaction, the approval window
+  runs with `chrome.runtime.sendMessage` wrapped to record what it sends, and in
+  the tests that reject a site connection the prompt gets a click listener that
+  records that Reject was pressed; neither changes what the window does.
+- The tap to copy test first grants clipboard permission to every page in the
+  browser, which the manifest does not ask for, so whether a real popup may
+  write to the clipboard on a click alone is not covered.
+- The layout tests for an over-long flash message and for the password error
+  lines write the text straight into the page instead of letting the popup's
+  code put it there, and the second brings each screen up by toggling its
+  `hidden` class rather than navigating to it; they cover the layout, not the
+  code that fills it.
+- Leaving the recovery phrase or private key screen while its decrypt runs is
+  forced by clicking Reveal and the settings gear in one page task, which a
+  person cannot do; the case a person can hit, the first decrypt after the popup
+  opens while libsodium is still loading, is not driven.
 
 Any test that drives a failure path on purpose declares the `console.error` it
 is about to provoke, via `errors.expect()`. That is not a mute: the declaration
@@ -446,8 +473,8 @@ collecting for a fixed grace period after the last test returns
 the context. A request whose _first_ dispatch falls after that window is never
 seen at all and cannot fail the run. In practice a request a test fires without
 awaiting reaches the route handler about 10ms later, and anything on a repeating
-timer gets observed on an earlier tick during the ~20s suite — but a one-shot
+timer gets observed on an earlier tick during the suite — but a one-shot call
-call deliberately deferred past the window will escape.
+deliberately deferred past the window will escape.
 
 That interception covers the MV3 background service worker as well as the popup
 page, which it does not by default — `script/test-e2e` sets
@@ -501,10 +528,11 @@ Chrome that ever changes this fails the run instead of passing it.
 `make test-e2e-firefox` builds `dist/firefox/` and drives the **real popup in a
 real Firefox**, installed as an unpacked MV2 temporary add-on via geckodriver.
 It covers popup load, the StateRecovery screen (the same cases as the Chrome
-suite), wallet creation through the UI, the Add Token screen, and the four dApp
+suite), wallet creation through the UI, the Add Token screen, and the dApp round
-round trips — `eth_requestAccounts`, `personal_sign`, `eth_sendTransaction`, and
+trips — `eth_requestAccounts`, `personal_sign`, `wallet_switchEthereumChain`
-a closed approval window rejecting with EIP-1193 4001 — driven through the real
+rejected and then approved, `eth_sendTransaction`, and a closed approval window
-content script, background page and approval windows.
+rejecting with EIP-1193 4001 — driven through the real content script,
+background page and approval windows.
 
 The suite lives in `tests/e2e/firefox/`. Its WebDriver client (`driver.js`) has
 **no npm dependencies at all**: it is built on global `fetch` and
@@ -579,25 +607,18 @@ without an `await`. Demonstrated, not assumed: a `throw` placed past the first
 and on Chrome (`pageerror`), with the rest of the run unaffected because the
 approval view had already rendered.
 
-One error is tolerated rather than fatal, listed in `ALLOWED_ERRORS` in
+Errors are read from the privileged `nsIConsoleService` in Marionette's chrome
-`tests/e2e/firefox/run.js` with the issue that will delete it, and printed on
+context and filtered to non-warning entries whose `sourceName` is the extension
-every occurrence so the concession stays visible in the run output. It is
+origin. That mechanism is not a stylistic choice. WebDriver BiDi's
-Firefox reporting the site-approval popup's unawaited `sendMessage` settling
+`log.entryAdded` delivers **nothing** for extension pages: on a plain `http://`
-after `window.close()` unloaded the context — the same teardown ordering as
+page it reports uncaught errors with stack traces, and on the `moz-extension://`
-[#275](https://git.eeqj.de/sneak/AutistMask/issues/275), and unsuppressable from
+popup it reports zero events, because Firefox's remote agent excludes extension
-the calling code, because `BaseContext.wrapPromise` reports it whether or not a
+browsing contexts from BiDi observation. Any harness built on Playwright-BiDi or
-handler is attached. Errors are read from the privileged `nsIConsoleService` in
+Puppeteer-BiDi would therefore see nothing and report success, which is exactly
-Marionette's chrome context and filtered to non-warning entries whose
+the vacuous check this repo has already shipped twice. Do not migrate this suite
-`sourceName` is the extension origin. That mechanism is not a stylistic choice.
+to BiDi.
-WebDriver BiDi's `log.entryAdded` delivers **nothing** for extension pages: on a
-plain `http://` page it reports uncaught errors with stack traces, and on the
-`moz-extension://` popup it reports zero events, because Firefox's remote agent
-excludes extension browsing contexts from BiDi observation. Any harness built on
-Playwright-BiDi or Puppeteer-BiDi would therefore see nothing and report
-success, which is exactly the vacuous check this repo has already shipped twice.
-Do not migrate this suite to BiDi.
 
-Two limits are worth knowing, both real differences from the Chrome suite:
+Three limits are worth knowing, all real differences from the Chrome suite:
 
 - **Error capture is poll-based, not event-streamed.** The console is drained at
   each step boundary, so an error is attributed to the step it was drained
@@ -614,24 +635,30 @@ Two limits are worth knowing, both real differences from the Chrome suite:
   and silently evicts the oldest, so more than 250 console messages between two
   drains destroys the excess unread. 400 throws inside one step are reported as
   exactly the newest 250, three runs running. That buffer is shared with
-  Firefox's own console noise; a clean run peaks at 4 of 250 at the install
+  Firefox's own console noise; a clean run, measured when the suite had three
-  drain and 0 at every later drain, so the three steps here have wide headroom,
+  steps (popup load, wallet creation and Add Token), peaked at 4 of 250 at the
-  but a step that logs heavily could evict unread errors. What poll-based costs
+  install drain and 0 at every later drain, but a step that logs heavily could
-  is location, not coverage: an error cannot be placed within a step the way the
+  evict unread errors. What poll-based costs is location, not coverage: an error
-  Chrome suite's `pageerror` events place it.
+  cannot be placed within a step the way the Chrome suite's `pageerror` events
+  place it.
 - **Almost nothing is stubbed, which inverts the coverage of network-dependent
   code.** The container still runs with `--network none`, so the run is offline
   and no request can escape. The one thing it can reach is the loopback fixture
   in `tests/e2e/firefox/dapp.js`, which serves the dApp page and a JSON-RPC node
   and which the extension's `rpcUrl` is pointed at for the dApp steps; a
   JSON-RPC method that fixture does not model fails the run rather than
-  answering `null`. Everything else — Blockscout, the price feed, the phishing
+  answering `null`. Everything else, Blockscout and the price feed among it, has
-  blocklist — has no fixture and simply fails, and the extension swallows its
+  no fixture and simply fails, and the extension swallows its own fetch
-  own fetch failures, so only the _failure_ branches of that code are ever
+  failures, so only the _failure_ branches of that code are ever executed. A
-  executed. A `ReferenceError` in the success path of `renderTransactions`, or
+  `ReferenceError` in the success path of `renderTransactions`, or of price
-  of price rendering, passes this suite green. The offline run is also weaker
+  rendering, passes this suite green. The offline run is also weaker than the
-  than the Chrome suite's interception for those calls: it proves nothing got
+  Chrome suite's interception for those calls: it proves nothing got out, but it
-  out, but it cannot report which requests were attempted.
+  cannot report which requests were attempted.
+- **The site-connection prompt always opens in a window of its own.** The
+  profile turns off `extensions.openPopupWithoutUserGesture.enabled`, so
+  `src/background/index.js` falls back from the toolbar popup, which WebDriver
+  cannot see, to `windows.create()`; the toolbar popup path is not covered on
+  Firefox.
 
 Neither `make test-e2e` nor `make test-e2e-firefox` is part of `make check` or
 `make test`. `REPO_POLICIES.md` caps `make test` at 60 seconds and a browser
@@ -1240,14 +1267,21 @@ path rather than on the home screen. Read the claim narrowly, as that file
 states it: what those boots prove is no structural dereference on the code paths
 a WHOLLY-CORRUPTED PROFILE takes, which is not every path a stored record takes.
 Not driven: any pairing of values the four slots do not produce, a view only
-forward navigation opens, anything behind a click, and everything a healthy
+forward navigation opens, anything behind a click or a timer, and, of what a
-profile reaches. Within that boundary the verdict is unconditional — if one of
+healthy profile reaches, anything beyond its boot onto each view the popup can
-those boots leaves the popup unhealthy or off the view it stored, `make check`
+reopen onto. The fields the router does not read share a slot on each boot, so
-fails, including when it takes two corrupted fields at once, because the verdict
+one of them truthy while another is falsy is reached only where the falsy slot
-is the combined boot and the per-field re-boot that names a culprit can only
+pairs a field that cannot be falsy with one that is. Within that boundary the
-decorate the message. So does a field that gains a floor while its row still
+verdict is unconditional — if one of those boots leaves the popup unhealthy,
-claims it has none, and so does a field added to `PERSISTED_FIELDS` with no row
+`make check` fails, including when it takes two corrupted fields at once,
-at all. The per-field justification that used to live in the header of
+because the verdict is the combined boot and the per-field re-boot that names a
+culprit can only decorate the message. The combined boot must also land on the
+view it stored, and each value driven only onto the restore path must land on
+its view, or fall back to Home, as its row declares; a field the router reads
+can legitimately change which view renders, so its own sweep is held to health
+alone. `make check` also fails on a field that gains a floor while its row still
+claims it has none, and on a field added to `PERSISTED_FIELDS` with no row at
+all. The per-field justification that used to live in the header of
 `src/shared/stateSchema.js` shipped a false claim in three consecutive changes,
 each caught only by a reviewer re-deriving thirty fields by hand.
 
@@ -1421,14 +1455,17 @@ view would leave a wallet one click from deletion.
       without it, the lost-password route on DeleteWallet is the first they
       would hear of it. The hint line reserves its height, so switching tabs
       cannot move the password fields under the pointer.
-    - "Import" button
+    - "Import" button, with the error line beside it so that it adds no height
+      to a screen whose button already starts near the bottom of the popup
 - **Transitions**:
     - "Import" with a valid entry and a matching password of at least 12
       characters → creates the wallet, clears the navigation stack, and →
       **Home**. The phrase and xprv modes then scan for further used addresses
       and report the count as a flash message.
-    - "Import" with an invalid entry, a duplicate wallet or address, or a short
+    - "Import" with a missing, short or mismatched password → full-sentence
-      or mismatched password → flash message, no screen change
+      error on the error line, no screen change
+    - "Import" with an invalid entry or a duplicate wallet or address → flash
+      message, no screen change
     - "Back" → previous screen (Welcome, Home, or Settings)
 
 #### AddressDetail (`address`)
@@ -1467,8 +1504,8 @@ view would leave a wallet one click from deletion.
       copy)
     - Warning that anyone holding the private key can transfer all funds from
       the address
-    - Error line
+    - Password input, error line and "Reveal" button, shown until the key is
-    - Password input and "Reveal" button, shown until the key is revealed
+      revealed
     - The private key on a highlighted background, tap to copy, shown only after
       the password has been accepted
 - **Transitions**:
@@ -1487,6 +1524,14 @@ view would leave a wallet one click from deletion.
   route, including the Settings gear. A decrypt still running when the screen is
   left is discarded rather than written. The screen is not restorable, so
   reopening the popup lands on Home rather than back on the key.
+- **Clipboard**: tapping the key copies it to the clipboard, and the wallet
+  never clears the clipboard afterwards; leaving the screen wipes the key from
+  the page only. The clipboard is the user's, not the wallet's. Clearing it
+  would go against what the user expects, and by then they may have copied
+  something else vital that the clear would destroy. The user knows the key is
+  secret from the warning above the password input, which says that anyone with
+  it can access and transfer all funds from the address, and knows it is on the
+  clipboard because they copied it. From then on it is theirs to manage.
 
 #### AddressToken (`address-token`)
 
@@ -1741,8 +1786,12 @@ view would leave a wallet one click from deletion.
       plus a "+ Add token" button
     - Display: "Show tracked tokens with zero balance" checkbox, "UTC
       Timestamps" checkbox, and a Theme selector (System / Light / Dark)
-    - Network: network selector (Ethereum Mainnet / Sepolia Testnet); switching
+    - Network: network selector (Ethereum Mainnet / Sepolia Testnet). The
-      resets the RPC and Blockscout endpoints to that network's defaults
+      network changes only here, or when the user approves a site's request on
+      **NetworkApproval**; either way, switching restores the RPC and Blockscout
+      endpoints last used on that network, or that network's defaults if it has
+      none, and sends `chainChanged` with the new chain id to every open tab.
+      Choosing the network already active changes nothing and sends nothing
     - Ethereum RPC: endpoint URL input + "Save" button (validated against
       `eth_chainId` before being saved)
     - Blockscout API: endpoint URL input + "Save" button (validated against
@@ -1798,8 +1847,8 @@ view would leave a wallet one click from deletion.
     - Wallet name
     - Warning box stating that anyone holding these words can take everything in
       the wallet, from any device, without the password
-    - Error line
+    - Password input, error line and "Reveal" button, shown until the password
-    - Password input + "Reveal" button, shown until the password is accepted
+      is accepted
     - The recovery phrase itself, in full and click-to-copy, shown only after a
       correct password and in place of the password prompt
 - **Transitions**:
@@ -1817,6 +1866,9 @@ view would leave a wallet one click from deletion.
   gear. A decrypt still running when the screen is left is discarded rather than
   written. The screen is not restorable, so reopening the popup lands on Home
   rather than back on the phrase.
+- **Clipboard**: tapping the phrase copies it, and the wallet never clears the
+  clipboard afterwards, for the reasons given under ExportPrivKey; here the
+  warning box above the password input is what tells the user it is secret.
 
 #### DeleteWallet (`delete-wallet-confirm`)
 
@@ -1825,8 +1877,8 @@ view would leave a wallet one click from deletion.
     - "Back" button, "Delete Wallet" heading
     - Warning naming the wallet and stating that deletion is permanent and any
       funds are unrecoverable without the recovery phrase
-    - Error line
     - Password input
+    - Error line
     - "Confirm Delete" button
     - An underlined "I have lost my password" control
 - **Transitions**:
@@ -2027,7 +2079,10 @@ view would leave a wallet one click from deletion.
   no window and takes no nonce, and the site can send it again once the pending
   one is answered. The window is centred on the browser window the user was last
   in; if that was another approval window, or the browser refuses the centred
-  position, the browser picks the position.
+  position, the browser picks the position. The network shown is the one the
+  transaction was populated on, and a site cannot switch it without the user:
+  its `wallet_switchEthereumChain` request changes the network only when the
+  user approves it on **NetworkApproval**.
 - **Elements**:
     - "Transaction Request" heading
     - Phishing warning banner (shown when the hostname is on the phishing
@@ -2118,6 +2173,40 @@ view would leave a wallet one click from deletion.
     - Popup window closed without answering → the request is rejected with
       EIP-1193 code 4001
 
+#### NetworkApproval (`approve-network`)
+
+- **When**: A connected website asks to switch the network with
+  `wallet_switchEthereumChain`, naming a supported network other than the active
+  one. Only the user switches the network: until the user approves the request
+  here, it changes nothing — not the network, the RPC and Blockscout endpoints,
+  the balances or the cached token data — and no page is sent `chainChanged`.
+  Opened the same way as TxApproval, in a separate popup window. Only one exists
+  per site at a time: a further switch request from a site whose switch request
+  is still unanswered is refused with EIP-1193 code `-32002` and opens no
+  window. A request naming the network already active is answered at once and
+  opens nothing; one naming an unsupported chain is refused with code `4902`,
+  and one from a site that is not connected with code `4100`.
+  `wallet_addEthereumChain` never switches the network.
+- **Elements**:
+    - "Network Switch Request" heading
+    - Phishing warning banner (shown when the hostname is on the phishing
+      blocklist)
+    - Site origin (bold, scheme and port included) + "wants to switch the
+      wallet's network."
+    - Current network: its name
+    - Requested network: its name
+    - A line saying that switching changes the network for the whole wallet and
+      for every site
+    - "Switch" / "Reject" buttons
+- **Transitions**:
+    - "Switch" → closes popup; the background switches the network as
+      **Settings** does, restoring the RPC and Blockscout endpoints last used on
+      that network (or that network's defaults if it has none), sends
+      `chainChanged` to every open tab, and answers the site with success
+    - "Reject" → closes popup; the site is answered with EIP-1193 code 4001 and
+      nothing changes
+    - Popup window closed without answering → the same as "Reject"
+
 #### StateRecovery (`state-recovery`)
 
 - **When**: the stored profile fails `assertStateUsable()`. At open, that is
@@ -2412,6 +2501,8 @@ logged.
 - Sign transactions requested by connected sites (`eth_sendTransaction`)
 - Sign messages (`personal_sign`, `eth_sign`)
 - Sign typed data (`eth_signTypedData_v4`, `eth_signTypedData`)
+- Switch network at a connected site's request, once the user approves it
+  (`wallet_switchEthereumChain`)
 - Human-readable transaction decoding (ERC-20, Uniswap Universal Router)
 - ETH/USD and token/USD price display
 - Configurable RPC endpoint and Blockscout API
@@ -2604,7 +2695,7 @@ Currently supported:
 
 ### Non-Goals for 1.0
 
-- Multi-chain support (Ethereum mainnet only)
+- Chains other than Ethereum mainnet and the Sepolia testnet
 - Hardware wallet support
 
 ## TODO
@@ -2638,7 +2729,10 @@ Currently supported:
 ## Policies
 
 - We don't mention "the other wallet" by name in code or documentation. We're
-  our own thing.
+  our own thing. Written exception: the injected provider in
+  `src/content/inpage.js` sets the flag named after the other wallet to `true`.
+  It is an interface-compatibility flag many dApps check, and without it the
+  wallet stops working on their sites.
 - The README is the complete authoritative technical documentation. It's ok if
   it gets big.
 

RULES.md

@@ -118,4 +118,7 @@ contradicts either, the originals govern.
 - [ ] "Address" not "account" or "derived key"
 - [ ] "Password" not "encryption key" or "vault passphrase"
 - [ ] Error messages are full sentences
-- [ ] No competitor mentioned by name in code or documentation
+- [ ] No competitor mentioned by name in code or documentation. Written
+      exception: the injected provider in `src/content/inpage.js` sets the flag
+      named after the other wallet to `true`, an interface-compatibility flag
+      many dApps check (README.md, Policies)

TODO.md

@@ -23,28 +23,149 @@
 
 pre-1.0, working towards the 1.0.0 milestone. Tagged v0.1.0 on 2026-02-27. The
 milestone is in flight on `next`; its `next` -> `main` PR is
-[#190](https://git.eeqj.de/sneak/AutistMask/pulls/190). `make check` verified
+[#388](https://git.eeqj.de/sneak/AutistMask/pulls/388). `make build` produces
-green on `next` at `e9fa8be` on 2026-08-10, and `make build` produces
+`dist/chrome/` and `dist/firefox/` with `DEBUG` compiled off, and checks them
-`dist/chrome/` and `dist/firefox/`, verified against the build's own receipt to
+against the build's own receipt to hold exactly the regular files and symlinks
-hold exactly the regular files and symlinks that build emitted, with `DEBUG`
+that build emitted.
-compiled off.
 
 The backlog lives on the
 [Gitea tracker](https://git.eeqj.de/sneak/AutistMask/issues), which is
 authoritative; this file does not duplicate it. Full policy file set present.
 Real-browser end-to-end suites (`make test-e2e` for Chrome,
-`make test-e2e-firefox` for Firefox) sit alongside `make check`, which now does
+`make test-e2e-firefox` for Firefox) sit alongside `make check`, which runs the
-static analysis as well as formatting, and `.gitea/workflows/e2e.yml` runs both
+tests, static analysis and the formatting check, and `.gitea/workflows/e2e.yml`
-of them on every push.
+runs both of them on every push.
 
 # Next Step
 
-Pre-1.0 security review of the extension (key handling, DEBUG mode policy, RPC
+Cut 1.0.0 once the
-input validation) before any 1.0rc tag. Individual filed issues are parts of it,
+[1.0.0 milestone](https://git.eeqj.de/sneak/AutistMask/milestone/6) is empty,
-but the review is broader than any of them.
+then continue tagging as milestones land.
 
 # Completed Steps
 
+- 2026-10-08: The browser suites no longer read a screen before the page has
+  shown it ([#502](https://git.eeqj.de/sneak/AutistMask/issues/502)). Their wait
+  for a screen used to pass as soon as the element laid out, which every view
+  does until the page's stylesheet has applied, so an approval test could read
+  the prompt's fields before the page's script had filled them. `visible()` in
+  `tests/e2e/harness.js` and `waitVisible()` in `tests/e2e/firefox/driver.js`
+  now also wait for the page to finish loading and for neither the element nor
+  anything around it to carry the `hidden` class that `showView()` puts on every
+  view but the current one. No caller changed.
+
+- 2026-10-08: Switching the network in Settings now tells open pages
+  ([#500](https://git.eeqj.de/sneak/AutistMask/issues/500)). Once the switch is
+  saved, Settings asks the background to send `chainChanged` with the new chain
+  id to every open tab, through the same function an approved site request uses.
+  Choosing the network already active changes nothing and sends nothing. Only
+  the extension's own pages can ask for this. `tests/chainSwitchGate.test.js`
+  drives the real Settings view against the background, and the Chrome suite
+  checks that the test page hears both switches.
+
+- 2026-10-07: A site can no longer switch the wallet's network by itself
+  ([#408](https://git.eeqj.de/sneak/AutistMask/issues/408)). A connected site's
+  `wallet_switchEthereumChain` request for the other supported network opens a
+  prompt in its own window, through the same approval machinery as the
+  transaction and signature prompts, naming the site, the current network and
+  the requested one. The network, its endpoints, the balances and the caches
+  change, and `chainChanged` is sent, only when the user approves it; rejecting
+  or closing the prompt answers 4001. One such prompt per site at a time. The
+  approval window no longer shows the connection prompt while it waits for the
+  background to describe the approval, because that prompt's "Allow" answers on
+  the same port as the new one; `tests/approvalWindow.test.js` checks that it
+  shows no screen until then. `tests/chainSwitchGate.test.js` and both browser
+  suites drive the prompt.
+
+- 2026-10-07: Two contradictions between the documents and the code are resolved
+  as ruled on [#165](https://git.eeqj.de/sneak/AutistMask/issues/165). The
+  README's 1.0 non-goal now puts Ethereum mainnet and the Sepolia testnet in
+  scope and other chains out of it. The injected provider's flag named after the
+  other wallet stays, as an interface-compatibility flag many dApps check, and
+  is written down as an exception to the rule against naming competitors in the
+  README's Policies section, in `RULES.md` and in a comment beside it in
+  `src/content/inpage.js`. `script/check-censored` already allows that flag only
+  in that file and its built copies, so it is unchanged.
+
+- 2026-10-07: Two holes in what `tests/persistedFieldContract.test.js` checks
+  are closed ([#379](https://git.eeqj.de/sneak/AutistMask/issues/379)). The
+  check that every swept field is driven both truthy and falsy counts only
+  `hostile` and `falsy` values, which the sweep drives onto every restorable
+  view, and no longer a `hostileRestore` value, which reaches only the views its
+  entry names; the stale index 5 moves into `hostile` for `selectedWallet` and
+  `selectedAddress`, as the one value of either still truthy after the floor.
+  Each `hostileRestore` entry declares whether its boot lands on its view or
+  falls back to Home, and is held to it. The limits that remain, fields that
+  share a slot on one boot and anything no stored record reaches by itself, are
+  restated as built in the file's header and the README, which now also say
+  which boots are held to where the popup lands and that a healthy profile is
+  booted onto every restorable view.
+
+- 2026-10-07: Every password error in the popup is shown the same way
+  ([#493](https://git.eeqj.de/sneak/AutistMask/issues/493)): with `showError()`
+  and `hideError()` in a fixed-height error line below the password field, as
+  the send confirmation and approval screens already did. The add wallet screen
+  showed a missing, short or mismatched password in the flash line, and the
+  private key export, recovery phrase and delete wallet screens each had a line
+  of their own above the field. On the add wallet screen the line sits beside
+  the Import button, so the button stays where it was at 360x600. Each line
+  clears when the screen is shown again and when the password is tried again.
+  The add wallet screen's other messages, such as an invalid recovery phrase, a
+  duplicate wallet and the address scan, stay in the flash line.
+  `tests/passwordErrorLines.test.js` drives all four screens in the popup.
+
+- 2026-10-07: Pre-1.0 security review of the extension
+  ([#383](https://git.eeqj.de/sneak/AutistMask/issues/383)), reading the tree at
+  `99292b9` for key handling, the DEBUG mode policy, and what the background
+  accepts from pages, the configured RPC endpoint and the explorer, with what
+  the approval screens show from it; the site permission model and storage were
+  read as well. Its summary on that issue lists ten findings, each filed as its
+  own issue, and all ten are fixed on `next`; one,
+  [#399](https://git.eeqj.de/sneak/AutistMask/issues/399), put funds at risk.
+  Three decisions it raised are still open with the owner: the Argon2id cost for
+  the vault key ([#401](https://git.eeqj.de/sneak/AutistMask/issues/401)), a
+  connected site switching the network with no prompt
+  ([#408](https://git.eeqj.de/sneak/AutistMask/issues/408)), and `eth_sign`
+  signing as a personal message
+  ([#409](https://git.eeqj.de/sneak/AutistMask/issues/409)). Not covered: the
+  end-to-end suites were not run, the bundled phishing blocklist and token list
+  were not checked entry by entry, `ethers` and `libsodium-wrappers-sumo` were
+  taken as audited, and nothing was tried against a real network with real funds
+  ([#385](https://git.eeqj.de/sneak/AutistMask/issues/385)). The planned
+  independent second check of each finding did not run; the findings rest on the
+  reviewer's own reading of the code.
+
+- 2026-10-07: Stale branches pruned from `origin`
+  ([#167](https://git.eeqj.de/sneak/AutistMask/issues/167)). The issue
+  classifies each branch it lists, with the evidence. The eighteen still on
+  `origin` that it classifies as landed, or superseded by merged pull requests,
+  were deleted. `feat/message-signing` and `fix/59-transaction-view-ui-policies`
+  had been deleted on 2026-09-09; both landed and stay deleted. Four are kept
+  because their work is not in `next`: `fix/consistent-error-display`,
+  `fix/87-consistent-error-display` and `fix/87-consistent-error-display-v2`,
+  the change for [#87](https://git.eeqj.de/sneak/AutistMask/issues/87) that
+  never landed, as reference for
+  [#493](https://git.eeqj.de/sneak/AutistMask/issues/493); and
+  `chore/token-list-enrichment`, deleted on 2026-09-09 and re-created at
+  `f7a2437`, whose `scripts/` tooling waits on
+  [#495](https://git.eeqj.de/sneak/AutistMask/issues/495).
+
+- 2026-10-07: The README says that the wallet never clears the clipboard after
+  the private key or the recovery phrase is copied, and why
+  ([#492](https://git.eeqj.de/sneak/AutistMask/issues/492)): the clipboard is
+  the user's, clearing it would go against what they expect, and it could
+  destroy something else they copied since. It is under ExportPrivKey, with a
+  line under ShowRecoveryPhrase, and names the warning each password screen
+  actually shows, which says nothing about the clipboard.
+
+- 2026-10-07: The Firefox end-to-end suite no longer tolerates any uncaught
+  extension error ([#487](https://git.eeqj.de/sneak/AutistMask/issues/487)). Its
+  one entry, Firefox reporting a popup promise that settled after the page
+  unloaded, had lost its cause with
+  [#275](https://git.eeqj.de/sneak/AutistMask/issues/275); the entry and the
+  code that printed tolerated errors are gone from `tests/e2e/firefox/run.js`,
+  and so is the README paragraph that described it.
+
 - 2026-10-07: The toolbar icons in `icons/` can be redrawn in the tree
   ([#378](https://git.eeqj.de/sneak/AutistMask/issues/378)): `make icons` runs
   `script/lib/icons.js`, which draws the mark and writes each PNG with node's
@@ -55,6 +176,20 @@ but the review is broader than any of them.
   zlib that made the committed files did. `build.js` now copies each manifest
   from the same path `copyIcons()` reads its icons from.
 
+- 2026-10-07: The README's end-to-end limits now match what the two browser
+  suites do to the extension
+  ([#293](https://git.eeqj.de/sneak/AutistMask/issues/293)). The `window.close`
+  override the issue named went with
+  [#275](https://git.eeqj.de/sneak/AutistMask/issues/275), so it needs no entry.
+  Added: both suites load the popup in a tab rather than from the toolbar;
+  Chrome waits 1.5 seconds before each site-connection request, records what
+  approval windows send and click, grants clipboard permission, writes text
+  straight into the page in two layout tests, and forces the leave during a
+  decrypt; Firefox forces the site-connection prompt into a window. Corrected:
+  Firefox's one tolerated error, whose cause that fix removed (the entry goes in
+  [#487](https://git.eeqj.de/sneak/AutistMask/issues/487)), the phishing
+  blocklist the extension no longer fetches, and two stale figures.
+
 - 2026-10-07: Back from Settings no longer shows Settings again after the
   settings gear was pressed on the recovery phrase or a delete wallet screen
   opened from Settings, with or without a reopen in between
@@ -1842,6 +1977,3 @@ but the review is broader than any of them.
 
 Only work that has no issue of its own belongs here; everything else is on the
 tracker.
-
-- Cut 1.0.0 once the milestone is empty, then continue tagging as milestones
-  land.

src/background/index.js

@@ -137,11 +137,12 @@ function releaseTxApprovalSlotFor(approvalId) {
     }
 }
 
-// One site-connection approval and one sign approval per site at a time: a
+// One site-connection approval, one sign approval and one network-switch
-// page that asks again before the user has answered is refused with the code
+// approval per site at a time: a page that asks again before the user has
-// above instead of opening another window, so it cannot bury the user in
+// answered is refused with the code above instead of opening another window,
-// prompts. The pending approval itself holds the place, so a caller must test
+// so it cannot bury the user in prompts. The pending approval itself holds the
-// this and raise its approval with nothing awaited in between.
+// place, so a caller must test this and raise its approval with nothing awaited
+// in between.
 function findPendingApproval(origin, type) {
     return Object.values(pendingApprovals).find(
         (approval) => approval.origin === origin && approval.type === type,
@@ -348,8 +349,9 @@ function settleApproval(id, result, options) {
 
 // What a pending approval resolves to when it is given up on rather than
 // answered: the window was closed, or could not be opened at all. A tx or sign
-// approval answers the requesting page in EIP-1193 shape; a site-connection
+// approval answers the requesting page in EIP-1193 shape; a site-connection or
-// approval answers the connection handler in its own.
+// network-switch approval answers its handler in the shape the popup's
+// decision has, as a refusal.
 function abandonedResult(approval, code, message) {
     if (approval.type === "tx" || approval.type === "sign") {
         return { error: { code, message } };
@@ -588,6 +590,26 @@ function requestSignApproval(origin, signParams, approvedFrom) {
     });
 }
 
+// Open a network-switch approval popup and return a promise that resolves with
+// { approved }. Opened in a window, as tx and sign approvals are, because a
+// site's request is not a user gesture. The popup answers on the approval port,
+// as a site-connection approval does.
+function requestNetworkApproval(origin, currentNetworkId, requestedNetworkId) {
+    return new Promise((resolve) => {
+        const id = crypto.randomUUID();
+        pendingApprovals[id] = {
+            id,
+            origin,
+            currentNetworkId,
+            requestedNetworkId,
+            resolve,
+            type: "network",
+        };
+
+        openApprovalWindow(id);
+    });
+}
+
 // Anything only the extension's own pages may say. A content script speaks
 // with the page's URL, so this is what separates the popup from the site the
 // popup is being asked about.
@@ -597,8 +619,8 @@ function isExtensionSender(sender) {
 }
 
 // The approval popup's port: it carries the user's decision on a
-// site-connection approval, and its disconnect is how that approval learns the
+// site-connection or network-switch approval, and its disconnect is how that
-// popup closed without one.
+// approval learns the popup closed without one.
 //
 // The decision travels this port rather than a one-off runtime.sendMessage()
 // for exactly one reason: the port is also what the popup's window.close()
@@ -806,6 +828,10 @@ async function handleRpc(method, params, origin) {
         // tab is served from, so a page the user never connected to must
         // not be able to do it. Ungated, any page could clear the
         // [TESTNET] banner under a user who believed they were on Sepolia.
+        //
+        // A connected site does not switch it either: only the user does,
+        // by approving the request on the prompt below
+        // (https://git.eeqj.de/sneak/AutistMask/issues/408).
         const s = await getState();
         const activeAddress = activeAddressOf(s);
         const allowed = s.allowedSites[activeAddress] || [];
@@ -827,6 +853,27 @@ async function handleRpc(method, params, origin) {
         }
         if (SUPPORTED_CHAIN_IDS.has(chainId)) {
             const target = networkByChainId(chainId);
+            if (findPendingApproval(origin, "network")) {
+                return {
+                    error: {
+                        code: APPROVAL_PENDING_CODE,
+                        message: APPROVAL_PENDING_MESSAGE,
+                    },
+                };
+            }
+            const decision = await requestNetworkApproval(
+                origin,
+                s.networkId,
+                target.id,
+            );
+            if (!decision.approved) {
+                return {
+                    error: {
+                        code: APPROVAL_REJECTED_CODE,
+                        message: APPROVAL_REJECTED_MESSAGE,
+                    },
+                };
+            }
             // Read-modify-write against storage. The old path went through
             // onChainSwitch(), which mutates the singleton and then persists
             // every field of it — on an unloaded worker that wrote empty
@@ -1345,20 +1392,21 @@ startBackgroundJobs();
 // which then fails retryably settles instead of waiting in a window that no
 // longer exists.
 //
-// A site-connection approval whose popup connected its port is not decided
+// A site-connection or network-switch approval whose popup connected its port
-// here. That popup approves and closes in the same breath, and this event
+// is not decided here. That popup approves and closes in the same breath, and
-// races the decision on a channel of its own — the same race the port exists
+// this event races the decision on a channel of its own — the same race the
-// to end. Its port disconnect says the same thing this event does, in an order
+// port exists to end. Its port disconnect says the same thing this event does,
-// that is defined, so the disconnect is left to say it. The window closing
+// in an order that is defined, so the disconnect is left to say it. The window
-// before any port connected is the one case with nothing else to speak for it,
+// closing before any port connected is the one case with nothing else to speak
-// and is rejected here so the dApp is not left waiting on a window that is
+// for it, and is rejected here so the dApp is not left waiting on a window that
-// gone.
+// is gone.
 if (windowsNs && windowsNs.onRemoved) {
     windowsNs.onRemoved.addListener((windowId) => {
         for (const [id, approval] of Object.entries(pendingApprovals)) {
             if (approval.windowId !== windowId) continue;
-            const isSite = approval.type !== "tx" && approval.type !== "sign";
+            const decidedOnPort =
-            if (isSite && approval.portConnected) continue;
+                approval.type !== "tx" && approval.type !== "sign";
+            if (decidedOnPort && approval.portConnected) continue;
             const rejection = abandonedResult(
                 approval,
                 APPROVAL_REJECTED_CODE,
@@ -1423,6 +1471,7 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         "AUTISTMASK_ADDRESSES_REMOVED",
         "AUTISTMASK_GET_CONNECTED_SITES",
         "AUTISTMASK_REMOVE_SITE",
+        "AUTISTMASK_NETWORK_CHANGED",
     ];
     if (POPUP_ONLY_TYPES.includes(msg.type) && !isExtensionSender(sender)) {
         sendResponse({ error: "Unauthorized sender" });
@@ -1446,6 +1495,11 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
                 resp.signParams = approval.signParams;
                 resp.approvedFrom = approval.approvedFrom;
             }
+            if (approval.type === "network") {
+                resp.type = "network";
+                resp.currentNetworkId = approval.currentNetworkId;
+                resp.requestedNetworkId = approval.requestedNetworkId;
+            }
             // Flag if the requesting domain is on the phishing blocklist.
             resp.isPhishingDomain = isPhishingDomain(
                 extractHostname(approval.origin),
@@ -1801,6 +1855,13 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         broadcastSiteRemoved(msg.origin);
         return false;
     }
+
+    // Settings switched the network and has saved it. Open tabs are told the
+    // new chain id the same way as after a site's approved switch request.
+    if (msg.type === "AUTISTMASK_NETWORK_CHANGED") {
+        broadcastChainChanged(msg.chainId);
+        return false;
+    }
 });
 
 module.exports = { PROXY_METHODS };

src/content/inpage.js

@@ -99,7 +99,10 @@
 
     const provider = {
         isAutistMask: true,
-        isMetaMask: true, // compatibility — many dApps check this
+        // An interface-compatibility flag many dApps check. Kept as a written
+        // exception to the rule that no competitor is named in code: see
+        // Policies in README.md, and RULES.md.
+        isMetaMask: true,
         chainId: currentChainId,
         networkVersion: currentNetworkVersion,
         selectedAddress: null,

src/popup/index.html

@@ -207,12 +207,22 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                     />
                 </div>
+                <!-- The error line sits beside Import, not above it: at
+                     360x600 the button already starts near the bottom of
+                     the popup, and a line of its own would push it below
+                     the fold. The longest error fits on one line here. -->
+                <div class="flex items-center gap-2">
                     <button
                         id="btn-add-wallet-confirm"
                         class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
                     >
                         Import
                     </button>
+                    <div
+                        id="add-wallet-password-error"
+                        class="text-xs min-h-[1.25rem] invisible"
+                    ></div>
+                </div>
             </div>
 
             <!-- ============ MAIN VIEW: ALL WALLETS & ADDRESSES ============ -->
@@ -396,10 +406,6 @@
                     Warning: anyone with this private key can access and
                     transfer all funds from this address. Never share it.
                 </p>
-                <div
-                    id="export-privkey-flash"
-                    class="text-xs mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div id="export-privkey-password-section" class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -408,9 +414,13 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                         placeholder="Enter your password to continue"
                     />
+                    <div
+                        id="export-privkey-password-error"
+                        class="text-xs mt-2 mb-2 min-h-[1.25rem] invisible"
+                    ></div>
                     <button
                         id="btn-export-privkey-confirm"
-                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mt-2"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
                     >
                         Reveal
                     </button>
@@ -1116,10 +1126,6 @@
                     <strong id="delete-wallet-name"></strong> is permanent. Any
                     funds will be unrecoverable without your recovery phrase.
                 </p>
-                <div
-                    id="delete-wallet-flash"
-                    class="text-xs text-red-500 mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -1129,6 +1135,10 @@
                         placeholder="Enter your password to confirm"
                     />
                 </div>
+                <div
+                    id="delete-wallet-password-error"
+                    class="text-xs mb-2 min-h-[1.25rem] invisible"
+                ></div>
                 <button
                     id="btn-delete-wallet-confirm"
                     class="border border-border text-red-500 px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
@@ -1273,10 +1283,6 @@
                     this wallet, from any device, without your password. Never
                     type them into a website and never show them to anyone.
                 </div>
-                <div
-                    id="show-phrase-flash"
-                    class="text-xs text-red-500 mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div id="show-phrase-password-section" class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -1285,9 +1291,13 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                         placeholder="Enter your password to continue"
                     />
+                    <div
+                        id="show-phrase-password-error"
+                        class="text-xs mt-2 mb-2 min-h-[1.25rem] invisible"
+                    ></div>
                     <button
                         id="btn-show-phrase-reveal"
-                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mt-2"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
                     >
                         Reveal
                     </button>
@@ -1731,6 +1741,54 @@
                 </div>
             </div>
 
+            <!-- ============ NETWORK SWITCH APPROVAL ============ -->
+            <div id="view-approve-network" class="view hidden">
+                <h2 class="font-bold mb-2">Network Switch Request</h2>
+                <div
+                    id="approve-network-phishing-warning"
+                    class="mb-3 p-2 text-xs font-bold hidden bg-red-100 text-red-800 border-2 border-red-600 rounded-md"
+                >
+                    ⚠️ PHISHING WARNING: This site is on a known phishing
+                    blocklist. Proceed with extreme caution.
+                </div>
+                <p class="mb-2">
+                    <span id="approve-network-origin" class="font-bold"></span>
+                    wants to switch the wallet's network.
+                </p>
+                <div class="mb-3">
+                    <div class="text-xs text-muted mb-1">Current network</div>
+                    <div
+                        id="approve-network-current"
+                        class="text-xs font-bold"
+                    ></div>
+                </div>
+                <div class="mb-3">
+                    <div class="text-xs text-muted mb-1">Requested network</div>
+                    <div
+                        id="approve-network-requested"
+                        class="text-xs font-bold"
+                    ></div>
+                </div>
+                <p class="mb-3 text-xs">
+                    Switching changes the network for the whole wallet and for
+                    every site, not only for this one.
+                </p>
+                <div class="flex justify-between">
+                    <button
+                        id="btn-approve-network"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                    >
+                        Switch
+                    </button>
+                    <button
+                        id="btn-reject-network"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                    >
+                        Reject
+                    </button>
+                </div>
+            </div>
+
             <!-- ============ STATE RECOVERY ============ -->
             <!--
                 Shown when the stored profile cannot be read at all. Every

src/popup/index.js

@@ -238,9 +238,9 @@ async function init() {
         // rejection rather than an uncaught error — measured as still failing
         // the run on both harnesses (Playwright `pageerror`, and the Firefox
         // driver's console-service drain), so nothing is lost by leaving it
-        // on that path.
+        // on that path. show() puts the approval's own screen up once the
+        // background has described it.
         approval.show(approvalId);
-        showView("approve-site");
         return;
     }
 

src/popup/views/addWallet.js

@@ -2,6 +2,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     goBack,
     clearViewStack,
     onViewLeave,
@@ -98,6 +100,7 @@ function clear() {
     $("add-wallet-password").value = "";
     $("add-wallet-password-confirm").value = "";
     $("add-wallet-phrase-warning").style.visibility = "hidden";
+    hideError("add-wallet-password-error");
 }
 
 // Each wallet has its own password (its own encryptedSecret), so adding a
@@ -125,15 +128,18 @@ function validatePassword() {
     const pw = $("add-wallet-password").value;
     const pw2 = $("add-wallet-password-confirm").value;
     if (!pw) {
-        showFlash("Please choose a password.");
+        showError("add-wallet-password-error", "Please choose a password.");
         return null;
     }
     if (pw.length < 12) {
-        showFlash("Password must be at least 12 characters.");
+        showError(
+            "add-wallet-password-error",
+            "Password must be at least 12 characters.",
+        );
         return null;
     }
     if (pw !== pw2) {
-        showFlash("Passwords do not match.");
+        showError("add-wallet-password-error", "Passwords do not match.");
         return null;
     }
     return pw;
@@ -342,8 +348,10 @@ function init(ctx) {
         $("add-wallet-phrase-warning").style.visibility = "visible";
     });
 
-    // Import / confirm
+    // Import / confirm. Each press starts with no password error on screen:
+    // validatePassword() puts it back if the password is still wrong.
     $("btn-add-wallet-confirm").addEventListener("click", async () => {
+        hideError("add-wallet-password-error");
         if (currentMode === "mnemonic") {
             await importMnemonic(ctx);
         } else if (currentMode === "privkey") {

src/popup/views/approval.js

@@ -14,6 +14,7 @@ const {
 } = require("./helpers");
 const { state, saveState } = require("../../shared/state");
 const {
+    networkById,
     networkByChainId,
     nativeCurrencyByChainId,
 } = require("../../shared/networks");
@@ -328,9 +329,9 @@ function showTxApproval(details) {
     const ethUsd = ethPrice ? parseFloat(ethValueFormatted) * ethPrice : null;
     const usdStr = formatUsd(ethUsd);
     // In the native currency of the network the transaction is for, which the
-    // Network line names, not the active network's: a site can switch the
+    // Network line names, not the active network's: the active network can
-    // active network after this transaction is prepared and back before it is
+    // change, in Settings or when the user approves a site's request, after
-    // signed.
+    // this transaction is prepared and change back before it is signed.
     $("approve-tx-value").textContent =
         ethValueFormatted +
         " " +
@@ -752,9 +753,29 @@ function showSignApproval(details) {
     );
 }
 
+function showNetworkApproval(details) {
+    showPhishingWarning(
+        "approve-network-phishing-warning",
+        details.isPhishingDomain,
+    );
+    $("approve-network-origin").textContent = details.origin;
+    $("approve-network-current").textContent = networkById(
+        details.currentNetworkId,
+    ).name;
+    $("approve-network-requested").textContent = networkById(
+        details.requestedNetworkId,
+    ).name;
+    showView("approve-network");
+}
+
 // Awaited by nobody: the popup entry point calls this and moves on. It
 // therefore has to absorb its own failure, and a background that cannot
 // describe the approval is the same outcome as an approval that is gone.
+//
+// Nothing is on screen until the background has described the approval, so
+// the screen shown is always the one for the approval this window answers:
+// the connection prompt's "Allow" and the network switch prompt's "Switch"
+// answer on the same port, and either would approve the other.
 async function show(id) {
     approvalId = id;
     approvalPort = runtimeApi().connect({ name: "approval:" + id });
@@ -778,6 +799,10 @@ async function show(id) {
         showSignApproval(details);
         return;
     }
+    if (details.type === "network") {
+        showNetworkApproval(details);
+        return;
+    }
     // Site connection approval
     showPhishingWarning(
         "approve-site-phishing-warning",
@@ -787,6 +812,7 @@ async function show(id) {
     $("approve-address").innerHTML = approvalAddressHtml(state.activeAddress);
     attachCopyHandlers("view-approve-site");
     $("approve-remember").checked = state.rememberSiteChoice;
+    showView("approve-site");
 }
 
 let approvalId = null;
@@ -866,20 +892,21 @@ function clearSignPassword() {
     hideError("approve-sign-error");
 }
 
-// Answer a site-connection approval and close. The decision goes out on the
+// Answer a site-connection or network-switch approval and close. The decision
-// approval port — see approvalPort above for why — and carries no approval id,
+// goes out on the approval port — see approvalPort above for why — and carries
-// because the port name already names the approval the background will settle.
+// no approval id, because the port name already names the approval the
-// The post is guarded because a throw must not cost the close: posting on a
+// background will settle. `remember` means something only for a site
-// port whose background worker has been torn down throws, and the approval it
+// connection. The post is guarded because a throw must not cost the close:
-// would have settled died with that worker, so the only thing left to do is
+// posting on a port whose background worker has been torn down throws, and the
-// what the user asked for — go away.
+// approval it would have settled died with that worker, so the only thing left
-function decideSite(approved) {
+// to do is what the user asked for — go away.
+function decide(approved, remember) {
     if (approvalPort) {
         try {
             approvalPort.postMessage({
                 type: "AUTISTMASK_APPROVAL_DECISION",
                 approved,
-                remember: $("approve-remember").checked,
+                remember,
             });
         } catch {
             // Nothing to report it to; the window closes either way.
@@ -898,11 +925,19 @@ function init(_ctx) {
     });
 
     $("btn-approve").addEventListener("click", () => {
-        decideSite(true);
+        decide(true, $("approve-remember").checked);
     });
 
     $("btn-reject").addEventListener("click", () => {
-        decideSite(false);
+        decide(false, $("approve-remember").checked);
+    });
+
+    $("btn-approve-network").addEventListener("click", () => {
+        decide(true, false);
+    });
+
+    $("btn-reject-network").addEventListener("click", () => {
+        decide(false, false);
     });
 
     $("btn-approve-tx").addEventListener("click", async () => {

src/popup/views/deleteWallet.js

@@ -2,6 +2,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     goBack,
     clearViewStack,
     onViewLeave,
@@ -55,8 +57,7 @@ function confirmKey(name) {
 function clear() {
     deleteWalletIndex = null;
     $("delete-wallet-password").value = "";
-    $("delete-wallet-flash").textContent = "";
+    hideError("delete-wallet-password-error");
-    $("delete-wallet-flash").style.visibility = "hidden";
 }
 
 // The lost-password screen holds no secret — a wallet name is not one —
@@ -232,19 +233,22 @@ function init(_ctx) {
     $("btn-delete-wallet-confirm").addEventListener("click", async () => {
         const pw = $("delete-wallet-password").value;
         if (!pw) {
-            $("delete-wallet-flash").textContent =
+            showError(
-                "Please enter your password.";
+                "delete-wallet-password-error",
-            $("delete-wallet-flash").style.visibility = "visible";
+                "Please enter your password.",
+            );
             return;
         }
 
         if (deleteWalletIndex === null) {
-            $("delete-wallet-flash").textContent =
+            showError(
-                "No wallet selected for deletion.";
+                "delete-wallet-password-error",
-            $("delete-wallet-flash").style.visibility = "visible";
+                "No wallet selected for deletion.",
+            );
             return;
         }
 
+        hideError("delete-wallet-password-error");
         const btn = $("btn-delete-wallet-confirm");
         btn.disabled = true;
         btn.classList.add("text-muted");
@@ -256,9 +260,10 @@ function init(_ctx) {
         try {
             await decryptWithPassword(wallet.encryptedSecret, pw);
         } catch {
-            $("delete-wallet-flash").textContent =
+            showError(
-                "That password is incorrect. Please try again.";
+                "delete-wallet-password-error",
-            $("delete-wallet-flash").style.visibility = "visible";
+                "That password is incorrect. Please try again.",
+            );
             btn.disabled = false;
             btn.classList.remove("text-muted");
             return;

src/popup/views/exportPrivkey.js

@@ -20,6 +20,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     flashCopyFeedback,
     goBack,
     onViewLeave,
@@ -56,11 +58,6 @@ function isCurrentReveal(generation) {
     );
 }
 
-function fail(message) {
-    $("export-privkey-flash").textContent = message;
-    $("export-privkey-flash").style.visibility = "visible";
-}
-
 // Wipe every trace of the key and drop the address selection. Safe to call
 // when nothing was ever revealed, and safe to call twice.
 function clear() {
@@ -71,8 +68,7 @@ function clear() {
     $("export-privkey-password").value = "";
     $("export-privkey-result").classList.add("hidden");
     $("export-privkey-password-section").classList.remove("hidden");
-    $("export-privkey-flash").textContent = "";
+    hideError("export-privkey-password-error");
-    $("export-privkey-flash").style.visibility = "hidden";
 }
 
 function show(walletIdx, addrIdx) {
@@ -112,15 +108,19 @@ function show(walletIdx, addrIdx) {
 async function reveal() {
     const password = $("export-privkey-password").value;
     if (!password) {
-        fail("Please enter your password.");
+        showError(
+            "export-privkey-password-error",
+            "Please enter your password.",
+        );
         return;
     }
     if (walletIndex === null) {
-        fail("No address is selected.");
+        showError("export-privkey-password-error", "No address is selected.");
         return;
     }
     const wallet = state.wallets[walletIndex];
 
+    hideError("export-privkey-password-error");
     const btn = $("btn-export-privkey-confirm");
     btn.disabled = true;
     btn.classList.add("text-muted");
@@ -140,11 +140,12 @@ async function reveal() {
         $("export-privkey-password-section").classList.add("hidden");
         $("export-privkey-value").textContent = signer.privateKey;
         $("export-privkey-result").classList.remove("hidden");
-        $("export-privkey-flash").textContent = "";
-        $("export-privkey-flash").style.visibility = "hidden";
     } catch {
         if (!isCurrentReveal(generation)) return;
-        fail("That password is incorrect. Please try again.");
+        showError(
+            "export-privkey-password-error",
+            "That password is incorrect. Please try again.",
+        );
     } finally {
         btn.disabled = false;
         btn.classList.remove("text-muted");

src/popup/views/helpers.js

@@ -51,6 +51,7 @@ const VIEWS = [
     "approve-site",
     "approve-tx",
     "approve-sign",
+    "approve-network",
     "export-privkey",
     "show-phrase",
     // Shown by src/popup/views/stateRecovery.js when the stored profile

src/popup/views/settings.js

@@ -316,7 +316,11 @@ function init(ctx) {
     const networkSelect = $("settings-network");
     networkSelect.addEventListener("change", async () => {
         const newId = networkSelect.value;
+        if (newId === state.networkId) return;
         const net = await onChainSwitch(newId);
+        // Open pages are told by the background, as after a site's approved
+        // switch request.
+        notify({ type: "AUTISTMASK_NETWORK_CHANGED", chainId: net.chainId });
         $("settings-rpc").value = state.rpcUrl;
         $("settings-blockscout").value = state.blockscoutUrl;
         showFlash("Switched to " + net.name + ".");

src/popup/views/showPhrase.js

@@ -21,6 +21,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     flashCopyFeedback,
     goBack,
     onViewLeave,
@@ -52,11 +54,6 @@ function isCurrentReveal(generation) {
     );
 }
 
-function fail(message) {
-    $("show-phrase-flash").textContent = message;
-    $("show-phrase-flash").style.visibility = "visible";
-}
-
 // Wipe every trace of the phrase and drop the wallet selection. Safe to
 // call when nothing was ever revealed, and safe to call twice.
 function clear() {
@@ -66,8 +63,7 @@ function clear() {
     $("show-phrase-password").value = "";
     $("show-phrase-result").classList.add("hidden");
     $("show-phrase-password-section").classList.remove("hidden");
-    $("show-phrase-flash").textContent = "";
+    hideError("show-phrase-password-error");
-    $("show-phrase-flash").style.visibility = "hidden";
 }
 
 function show(walletIdx) {
@@ -90,19 +86,23 @@ function show(walletIdx) {
 async function reveal() {
     const password = $("show-phrase-password").value;
     if (!password) {
-        fail("Please enter your password.");
+        showError("show-phrase-password-error", "Please enter your password.");
         return;
     }
     if (walletIndex === null) {
-        fail("No wallet is selected.");
+        showError("show-phrase-password-error", "No wallet is selected.");
         return;
     }
     const wallet = state.wallets[walletIndex];
     if (!walletHasRecoveryPhrase(wallet)) {
-        fail("This wallet does not have a recovery phrase.");
+        showError(
+            "show-phrase-password-error",
+            "This wallet does not have a recovery phrase.",
+        );
         return;
     }
 
+    hideError("show-phrase-password-error");
     const btn = $("btn-show-phrase-reveal");
     btn.disabled = true;
     btn.classList.add("text-muted");
@@ -120,13 +120,14 @@ async function reveal() {
         $("show-phrase-password-section").classList.add("hidden");
         $("show-phrase-value").textContent = phrase;
         $("show-phrase-result").classList.remove("hidden");
-        $("show-phrase-flash").textContent = "";
-        $("show-phrase-flash").style.visibility = "hidden";
     } catch {
         if (!isCurrentReveal(generation)) return;
         // Deliberately not the caught error: the message is fixed so that
         // nothing derived from the ciphertext or the attempt can surface.
-        fail("That password is incorrect. Please try again.");
+        showError(
+            "show-phrase-password-error",
+            "That password is incorrect. Please try again.",
+        );
     } finally {
         btn.disabled = false;
         btn.classList.remove("text-muted");

src/popup/views/transactionDetail.js

@@ -84,8 +84,9 @@ function show(tx) {
             contractAddress: tx.contractAddress || null,
             // The network the history entry was read from. The type line and
             // the fee are in its native currency, not the active network's:
-            // a site can switch the active network before a later popup
+            // the active network can change, in Settings or when the user
-            // shows this screen again.
+            // approves a site's request, before a later popup shows this
+            // screen again.
             chainId: tx.chainId,
         },
     };

src/popup/views/txStatus.js

@@ -89,8 +89,9 @@ function startWait(txInfo, txHash, broadcastTime, pollNow) {
 
     // A native amount, here and on the success and error screens, is in the
     // native currency of txInfo.chainId, the network the transaction was sent
-    // on, not the active network's: a site can switch the active network
+    // on, not the active network's: the active network can change, in
-    // while this screen is open or before a later popup resumes it.
+    // Settings or when the user approves a site's request, while this screen
+    // is open or before a later popup resumes it.
     const symbol =
         txInfo.token === "ETH"
             ? nativeCurrencyByChainId(txInfo.chainId)

tests/addressScanCancelled.test.js

@@ -39,6 +39,8 @@ jest.doMock("../src/popup/views/helpers", () => ({
     $: element,
     showView: () => {},
     showFlash: () => {},
+    showError: () => {},
+    hideError: () => {},
     goBack: () => {},
     clearViewStack: () => {},
     onViewLeave: () => {},

tests/approvalOrigin.test.js

@@ -1,5 +1,5 @@
-// The connection, transaction and signature prompts name the site by its full
+// The connection, transaction, signature and network switch prompts name the
-// origin, scheme and port included, not by its bare hostname
+// site by its full origin, scheme and port included, not by its bare hostname
 // (https://git.eeqj.de/sneak/AutistMask/issues/402). A page served over http,
 // or on another port, of a host the user trusts over https must not raise a
 // prompt that reads as that trusted site.
@@ -104,6 +104,7 @@ beforeEach(() => {
 test("the connection prompt shows the origin", async () => {
     await openApproval({});
     expect(node("approve-origin").textContent).toBe(ORIGIN);
+    expect(node("view-approve-site").classList.contains("hidden")).toBe(false);
 });
 
 test("the transaction prompt shows the origin", async () => {
@@ -138,3 +139,24 @@ test("the signature prompt shows the origin", async () => {
     });
     expect(node("approve-sign-origin").textContent).toBe(ORIGIN);
 });
+
+test("the network switch prompt shows the origin and both networks", async () => {
+    await openApproval({
+        type: "network",
+        currentNetworkId: "mainnet",
+        requestedNetworkId: "sepolia",
+    });
+    expect(node("approve-network-origin").textContent).toBe(ORIGIN);
+    expect(node("approve-network-current").textContent).toBe(
+        "Ethereum Mainnet",
+    );
+    expect(node("approve-network-requested").textContent).toBe(
+        "Sepolia Testnet",
+    );
+    // Its own screen, and not the connection prompt, whose "Allow" answers
+    // on the same port.
+    expect(node("view-approve-network").classList.contains("hidden")).toBe(
+        false,
+    );
+    expect(node("view-approve-site").classList.contains("hidden")).toBe(true);
+});

tests/approvalWindow.test.js

@@ -0,0 +1,47 @@
+// The approval window shows no screen until the background has described the
+// approval it answers (https://git.eeqj.de/sneak/AutistMask/issues/408). The
+// connection prompt's "Allow" and the network switch prompt's "Switch" answer
+// on the same port, so a window that showed the connection prompt while it
+// waited could approve a network switch.
+//
+// Booted through the real popup entry point, which is where the connection
+// prompt used to be put up before the background had answered.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    settle,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+afterEach(cleanupPopup);
+
+test("the approval window shows no screen until the background describes the approval", async () => {
+    // The background's answer, held until the test gives it.
+    let answer = null;
+    const env = await bootPopup(unversionedValidProfile(), {
+        search: "?approval=approval-1",
+        runtime: {
+            connect: () => ({ postMessage: () => {} }),
+            sendMessage: (msg, reply) => {
+                if (msg.type === "AUTISTMASK_GET_APPROVAL") answer = reply;
+            },
+        },
+    });
+
+    expect(answer).not.toBeNull();
+    // No screen at all, the connection prompt included.
+    expect(env.visibleViews()).toEqual([]);
+
+    answer({
+        type: "network",
+        origin: "https://dapp.example",
+        currentNetworkId: "mainnet",
+        requestedNetworkId: "sepolia",
+        isPhishingDomain: false,
+    });
+    await settle();
+
+    expect(env.visibleViews()).toEqual(["approve-network"]);
+    expect(env.pageErrors).toEqual([]);
+});

tests/backgroundStateIsolation.test.js

@@ -25,6 +25,7 @@
 
 const { Wallet } = require("ethers");
 const { networkById } = require("../src/shared/networks");
+const { applyChainSwitchFields } = require("../src/shared/chainSwitchFields");
 const { makeStorageStub } = require("./support/storageStub");
 
 const SIGNER_KEY =
@@ -240,8 +241,8 @@ describe("a chain switch under a transaction already committed to a chain", () =
     // The artifact is verified against the chain read at the top of the
     // attempt. Whatever endpoint it is then broadcast to has to be that same
     // chain's — otherwise the wallet checks a transaction against Sepolia and
-    // sends it to a mainnet node. A connected site can switch the chain at any
+    // sends it to a mainnet node. The user can switch the network in Settings
-    // moment, including this one.
+    // at any moment, including this one.
     test("the artifact is broadcast to the endpoint of the chain it was verified against", async () => {
         const bg = loadWorker("sepolia");
 
@@ -264,9 +265,9 @@ describe("a chain switch under a transaction already committed to a chain", () =
             populated(Number(SEPOLIA.networkVersion)),
         );
 
-        // A connected site switches the chain while the attempt is running,
+        // The user switches the network in Settings while the attempt is
-        // and the switch is committed to storage in full before the attempt
+        // running: the popup writes the switched record to storage in full
-        // goes any further.
+        // before the attempt goes any further.
         //
         // It is fired from inside the attempt's SECOND state read, because
         // that is where the window used to be: the chain id was captured at
@@ -277,18 +278,18 @@ describe("a chain switch under a transaction already committed to a chain", () =
         // this to fire on, and the switch below runs after the attempt is
         // done instead — which is the point.
         let reads = 0;
-        let switched = null;
+        let switched = false;
-        const doSwitch = async () => {
+        const doSwitch = () => {
-            switched = bg.rpc("wallet_switchEthereumChain", [
+            const record = bg.persisted();
-                { chainId: MAINNET.chainId },
+            applyChainSwitchFields(record, MAINNET.id);
-            ]);
+            global.chrome.storage.write("autistmask", record);
-            await settle();
+            switched = true;
         };
         bg.setGetHook(async () => {
             reads++;
             if (reads !== 2) return;
             bg.setGetHook(null);
-            await doSwitch();
+            doSwitch();
         });
 
         const attempt = bg.send(
@@ -303,8 +304,7 @@ describe("a chain switch under a transaction already committed to a chain", () =
         await settle();
 
         bg.setGetHook(null);
-        if (!switched) await doSwitch();
+        if (!switched) doSwitch();
-        expect(switched.result()).toEqual({ result: null });
         expect(bg.persisted().networkId).toBe("mainnet");
         await settle();
 

tests/chainSwitchGate.test.js

@@ -1,16 +1,24 @@
-// Who may move the active chain.
+// Who may move the active chain, and when.
 //
 // wallet_switchEthereumChain used to be answered for any origin at all, with
 // no connection check and no prompt, so a page the user had never connected
 // to could clear the [TESTNET] banner under someone who believed they were
-// on Sepolia (https://git.eeqj.de/sneak/AutistMask/issues/308). The refusal
+// on Sepolia (https://git.eeqj.de/sneak/AutistMask/issues/308). Gated on the
-// is asserted as a refusal to ACT — the state unmoved and no chainChanged
+// connection, a connected site could still move the wallet between mainnet and
-// broadcast — because an error code alone would not distinguish a gate from
+// Sepolia without asking. Only the user switches the network: a connected
-// a switch that happened and then reported a failure.
+// site's request opens a prompt, and nothing changes unless the user approves
+// it there (https://git.eeqj.de/sneak/AutistMask/issues/408).
 //
-// The endpoint half of that issue lives in tests/networkEndpoints.test.js,
+// Every refusal is asserted as a refusal to ACT — the stored record unmoved
-// which covers the popup's chain switch; this file covers the background's,
+// and no chainChanged broadcast — because an error code alone would not
-// which goes through storage rather than the shared state singleton.
+// distinguish a refusal from a switch that happened and then reported a
+// failure.
+//
+// The endpoint half of #308 lives in tests/networkEndpoints.test.js, which
+// covers the popup's chain switch; this file covers the background's, which
+// goes through storage rather than the shared state singleton. The last block
+// covers what the background tells open tabs when the user switches the
+// network in Settings.
 
 const { networkById } = require("../src/shared/networks");
 const { makeStorageStub } = require("./support/storageStub");
@@ -21,18 +29,23 @@ const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
 const CONNECTED_ORIGIN = "https://dapp.example";
 const STRANGER_ORIGIN = "https://stranger.example";
 
+const EXT_URL = "chrome-extension://autistmask/";
+
 const MAINNET = networkById("mainnet");
 const SEPOLIA = networkById("sepolia");
 
 // The user's own node, so a switch that happens is visible as the loss of it.
 const CUSTOM_RPC = "http://127.0.0.1:8545";
 
+// A balance a switch would clear, so a switch that happens is visible here too.
 function walletFixture() {
     return [
         {
             name: "Wallet 1",
             type: "hd",
-            addresses: [{ address: ADDRESS, balance: "0", tokenBalances: [] }],
+            addresses: [
+                { address: ADDRESS, balance: "1.5", tokenBalances: [] },
+            ],
         },
     ];
 }
@@ -47,10 +60,6 @@ afterEach(() => {
     delete global.chrome;
 });
 
-// ---------------------------------------------------------------------------
-// The gate: which origins the background will switch the chain for.
-// ---------------------------------------------------------------------------
-
 // Load the background worker against stubbed browser APIs, with the real
 // chain-switch and persistence modules behind it, and return the handles to
 // drive it.
@@ -91,30 +100,46 @@ function loadBackground() {
     const storage = makeStorageStub({ autistmask: persisted });
 
     let messageListener = null;
+    let connectListener = null;
+    let windowRemovedListener = null;
+    // The URL of every approval window the background opened. The approval id
+    // is in it, and that is how the popup learns which approval it answers.
+    const opened = [];
     // Every message the background pushed at a content script. chainChanged
-    // is what tells a page the wallet moved, so an ungated switch is visible
+    // is what tells a page the wallet moved, so a switch is visible here as
-    // here as well as in the state.
+    // well as in the state.
     const toTabs = [];
 
     global.chrome = {
         storage,
         runtime: {
-            getURL: (path) => "chrome-extension://autistmask/" + path,
+            getURL: (path) => EXT_URL + path,
             onMessage: {
                 addListener: (fn) => {
                     messageListener = fn;
                 },
             },
-            onConnect: { addListener: () => {} },
+            onConnect: {
+                addListener: (fn) => {
+                    connectListener = fn;
+                },
+            },
             lastError: null,
         },
         windows: {
             getLastFocused: (cb) => cb(null),
-            create: (options, cb) => cb({ id: 1 }),
+            create: (options, cb) => {
+                opened.push(options.url);
+                cb({ id: opened.length });
+            },
             remove: (id, cb) => {
                 if (cb) cb();
             },
-            onRemoved: { addListener: () => {} },
+            onRemoved: {
+                addListener: (fn) => {
+                    windowRemovedListener = fn;
+                },
+            },
         },
         tabs: {
             query: (queryInfo, cb) => cb([{ id: 1 }]),
@@ -128,6 +153,8 @@ function loadBackground() {
 
     require("../src/background/index");
 
+    // A page's request. Its answer is read with result(), which is null for as
+    // long as the request is waiting on the user.
     async function switchChain(chainId, origin) {
         let result = null;
         messageListener(
@@ -142,55 +169,309 @@ function loadBackground() {
             },
         );
         await settle();
-        return result;
+        return { result: () => result };
+    }
+
+    function promptId() {
+        return new URL(opened[opened.length - 1]).searchParams.get("approval");
+    }
+
+    // What the popup is told to show for the prompt.
+    function describePrompt() {
+        let reply = null;
+        messageListener(
+            { type: "AUTISTMASK_GET_APPROVAL", id: promptId() },
+            { url: EXT_URL + "src/popup/index.html" },
+            (r) => {
+                reply = r;
+            },
+        );
+        return reply;
+    }
+
+    // The user's answer, as the popup sends it: on the port named for the
+    // approval, from the extension's own page, and then the window closes.
+    async function answerPrompt(approved) {
+        const onMessage = [];
+        const onDisconnect = [];
+        const port = {
+            name: "approval:" + promptId(),
+            sender: { url: EXT_URL + "src/popup/index.html" },
+            onMessage: { addListener: (fn) => onMessage.push(fn) },
+            onDisconnect: { addListener: (fn) => onDisconnect.push(fn) },
+        };
+        connectListener(port);
+        for (const fn of onMessage) {
+            fn(
+                {
+                    type: "AUTISTMASK_APPROVAL_DECISION",
+                    approved,
+                    remember: false,
+                },
+                port,
+            );
+        }
+        for (const fn of onDisconnect) fn(port);
+        await settle();
+    }
+
+    // The user closes the prompt window without answering it.
+    async function closePrompt() {
+        windowRemovedListener(opened.length);
+        await settle();
     }
 
     return {
         switchChain,
+        describePrompt,
+        answerPrompt,
+        closePrompt,
+        opened,
+        // A message to the background from `sender`, and its answer.
+        send: (msg, sender) => {
+            let reply = null;
+            messageListener(msg, sender, (r) => {
+                reply = r;
+            });
+            return reply;
+        },
         walletState: () => storage.read("autistmask"),
         chainChangedEvents: () =>
             toTabs.filter((m) => m.eventName === "chainChanged"),
     };
 }
 
+const USER_REJECTED = { code: 4001, message: "User rejected the request." };
+
 describe("wallet_switchEthereumChain is gated on the connection", () => {
     test("an origin the wallet was never connected to is refused with 4100", async () => {
         const bg = loadBackground();
+        const before = bg.walletState();
 
-        const result = await bg.switchChain(SEPOLIA.chainId, STRANGER_ORIGIN);
+        const request = await bg.switchChain(SEPOLIA.chainId, STRANGER_ORIGIN);
 
-        expect(result.error).toEqual({ code: 4100, message: "Unauthorized" });
+        expect(request.result().error).toEqual({
-        expect(result.result).toBeUndefined();
+            code: 4100,
+            message: "Unauthorized",
+        });
+        expect(request.result().result).toBeUndefined();
         // The refusal has to be a refusal to ACT, not just an error string:
         // the wallet is still on mainnet, still on the user's own node, and
-        // no page was told the chain moved.
+        // no page was told the chain moved. Nor was the user asked.
-        expect(bg.walletState().networkId).toBe("mainnet");
+        expect(bg.walletState()).toEqual(before);
-        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
         expect(bg.chainChangedEvents()).toEqual([]);
+        expect(bg.opened).toEqual([]);
     });
 
     test("an unconnected origin is refused even for the chain already active", async () => {
         const bg = loadBackground();
 
-        const result = await bg.switchChain(MAINNET.chainId, STRANGER_ORIGIN);
+        const request = await bg.switchChain(MAINNET.chainId, STRANGER_ORIGIN);
 
-        expect(result.error).toEqual({ code: 4100, message: "Unauthorized" });
+        expect(request.result().error).toEqual({
+            code: 4100,
+            message: "Unauthorized",
+        });
     });
 
     test("an unconnected origin is refused before the unsupported-chain answer", async () => {
         const bg = loadBackground();
 
-        const result = await bg.switchChain("0x89", STRANGER_ORIGIN);
+        const request = await bg.switchChain("0x89", STRANGER_ORIGIN);
 
-        expect(result.error.code).toBe(4100);
+        expect(request.result().error.code).toBe(4100);
+    });
+});
+
+describe("only the user switches the network", () => {
+    test("a connected site's request changes nothing while the prompt is open", async () => {
+        const bg = loadBackground();
+        const before = bg.walletState();
+
+        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+
+        // Waiting on the user, with one prompt on screen naming the site and
+        // both networks.
+        expect(request.result()).toBeNull();
+        expect(bg.opened).toHaveLength(1);
+        expect(bg.describePrompt()).toMatchObject({
+            origin: CONNECTED_ORIGIN,
+            type: "network",
+            currentNetworkId: "mainnet",
+            requestedNetworkId: "sepolia",
         });
 
-    test("a connected origin switches the chain", async () => {
+        // The network, the endpoints and the balances are as they were, and
+        // no page was told otherwise.
+        expect(bg.walletState()).toEqual(before);
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+
+    test("approving the prompt switches the network", async () => {
         const bg = loadBackground();
 
-        const result = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        await bg.answerPrompt(true);
+
+        expect(request.result()).toEqual({ result: null });
+        const after = bg.walletState();
+        expect(after.networkId).toBe("sepolia");
+        expect(after.rpcUrl).toBe(SEPOLIA.defaultRpcUrl);
+        expect(after.wallets[0].addresses[0].balance).toBe("0");
+        expect(bg.chainChangedEvents()).toEqual([
+            {
+                type: "AUTISTMASK_EVENT",
+                eventName: "chainChanged",
+                data: SEPOLIA.chainId,
+            },
+        ]);
+    });
+
+    test("rejecting the prompt changes nothing and answers 4001", async () => {
+        const bg = loadBackground();
+        const before = bg.walletState();
+
+        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        await bg.answerPrompt(false);
+
+        expect(request.result()).toEqual({ error: USER_REJECTED });
+        expect(bg.walletState()).toEqual(before);
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+
+    test("closing the prompt without answering changes nothing and answers 4001", async () => {
+        const bg = loadBackground();
+        const before = bg.walletState();
+
+        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        await bg.closePrompt();
+
+        expect(request.result()).toEqual({ error: USER_REJECTED });
+        expect(bg.walletState()).toEqual(before);
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+
+    test("a request for the chain already active opens no prompt", async () => {
+        const bg = loadBackground();
+        const before = bg.walletState();
+
+        const request = await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);
+
+        expect(request.result()).toEqual({ result: null });
+        expect(bg.opened).toEqual([]);
+        expect(bg.walletState()).toEqual(before);
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+
+    test("a second request while the prompt is open is refused with -32002", async () => {
+        const bg = loadBackground();
+
+        const first = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        const second = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+
+        expect(second.result().error.code).toBe(-32002);
+        expect(bg.opened).toHaveLength(1);
+
+        // The first prompt still decides.
+        await bg.answerPrompt(true);
+        expect(first.result()).toEqual({ result: null });
+        expect(bg.walletState().networkId).toBe("sepolia");
+    });
+
+    test("a request for an unsupported chain still gets 4902 and no prompt", async () => {
+        const bg = loadBackground();
+
+        const request = await bg.switchChain("0x89", CONNECTED_ORIGIN);
+
+        expect(request.result().error.code).toBe(4902);
+        expect(bg.opened).toEqual([]);
+        expect(bg.walletState().networkId).toBe("mainnet");
+    });
+
+    test("an approved switch keeps the user's endpoint", async () => {
+        const bg = loadBackground();
+
+        await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        await bg.answerPrompt(true);
+        expect(bg.walletState().rpcUrl).toBe(SEPOLIA.defaultRpcUrl);
+
+        await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);
+        await bg.answerPrompt(true);
+        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
+    });
+});
+
+// Switching the network in Settings tells open pages, as an approved site
+// request does (https://git.eeqj.de/sneak/AutistMask/issues/500). These drive
+// the real Settings view over the background's storage, with what it sends
+// delivered to the background from the extension's own page.
+describe("switching the network in Settings tells every open tab", () => {
+    const POPUP = { url: EXT_URL + "src/popup/index.html" };
+
+    // A stand-in for one DOM node: enough of an element for init() to set
+    // properties on it and hang listeners off it.
+    function fakeElement() {
+        return {
+            value: "",
+            checked: false,
+            textContent: "",
+            style: {},
+            dataset: {},
+            classList: { add() {}, remove() {} },
+            listeners: {},
+            addEventListener(event, handler) {
+                this.listeners[event] = handler;
+            },
+            querySelectorAll: () => [],
+        };
+    }
+
+    // Settings, opened the way the popup opens it. Returns its network
+    // selector.
+    async function openSettings(bg) {
+        const elements = {};
+        const element = (id) => (elements[id] ||= fakeElement());
+        jest.doMock("../src/popup/views/helpers", () => ({
+            $: element,
+            showView: () => {},
+            updateDebugBanner: () => {},
+            showFlash: () => {},
+            escapeHtml: (s) => s,
+            flashCopyFeedback: () => {},
+            goBack: () => {},
+            pushCurrentView: () => {},
+            onViewLeave: () => {},
+            VIEWS: [],
+        }));
+        global.chrome.runtime.sendMessage = (msg) => {
+            bg.send(msg, POPUP);
+        };
+        await require("../src/shared/state").loadState();
+        require("../src/popup/views/settings").init({
+            pageClosed: new AbortController().signal,
+        });
+        const select = element("settings-network");
+        select.value = "mainnet";
+        return select;
+    }
+
+    // The user picks `networkId` in the selector.
+    async function choose(select, networkId) {
+        select.value = networkId;
+        await select.listeners.change();
+        await settle();
+    }
+
+    afterEach(() => {
+        jest.dontMock("../src/popup/views/helpers");
+    });
+
+    test("switching to the other network sends chainChanged once, with its chain id", async () => {
+        const bg = loadBackground();
+        const select = await openSettings(bg);
+
+        await choose(select, "sepolia");
 
-        expect(result).toEqual({ result: null });
         expect(bg.walletState().networkId).toBe("sepolia");
         expect(bg.chainChangedEvents()).toEqual([
             {
@@ -201,22 +482,27 @@ describe("wallet_switchEthereumChain is gated on the connection", () => {
         ]);
     });
 
-    test("a connected origin asking for an unsupported chain still gets 4902", async () => {
+    test("choosing the network already active changes nothing and sends nothing", async () => {
         const bg = loadBackground();
+        const select = await openSettings(bg);
+        const before = bg.walletState();
 
-        const result = await bg.switchChain("0x89", CONNECTED_ORIGIN);
+        await choose(select, "mainnet");
 
-        expect(result.error.code).toBe(4902);
+        expect(bg.walletState()).toEqual(before);
-        expect(bg.walletState().networkId).toBe("mainnet");
+        expect(bg.chainChangedEvents()).toEqual([]);
     });
 
-    test("a switch by a connected origin keeps the user's endpoint", async () => {
+    test("a page cannot make the background send chainChanged", async () => {
         const bg = loadBackground();
 
-        await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
+        const reply = bg.send(
-        expect(bg.walletState().rpcUrl).toBe(SEPOLIA.defaultRpcUrl);
+            { type: "AUTISTMASK_NETWORK_CHANGED", chainId: SEPOLIA.chainId },
+            { url: CONNECTED_ORIGIN + "/" },
+        );
+        await settle();
 
-        await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);
+        expect(reply).toEqual({ error: "Unauthorized sender" });
-        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
+        expect(bg.chainChangedEvents()).toEqual([]);
     });
 });

tests/coldWorkerChainSwitch.test.js

@@ -14,6 +14,10 @@
 // itself: the handler has to do it. tests/chainSwitchGate.test.js mocks the
 // state module wholesale and tests/networkEndpoints.test.js always loads
 // first, so neither can see this.
+//
+// A site's switch happens only once the user approves it on a prompt
+// (https://git.eeqj.de/sneak/AutistMask/issues/408), so every switch here is
+// approved the way the popup approves one.
 
 const { networkById } = require("../src/shared/networks");
 const { makeStorageStub } = require("./support/storageStub");
@@ -90,6 +94,9 @@ function loadColdWorker(networkId) {
     const storage = makeStorageStub({ autistmask: storedProfile(networkId) });
 
     let messageListener = null;
+    let connectListener = null;
+    // The URL of every approval window opened; the approval id is in it.
+    const opened = [];
     const toTabs = [];
 
     global.chrome = {
@@ -101,12 +108,19 @@ function loadColdWorker(networkId) {
                     messageListener = fn;
                 },
             },
-            onConnect: { addListener: () => {} },
+            onConnect: {
+                addListener: (fn) => {
+                    connectListener = fn;
+                },
+            },
             lastError: null,
         },
         windows: {
             getLastFocused: (cb) => cb(null),
-            create: (options, cb) => cb({ id: 1 }),
+            create: (options, cb) => {
+                opened.push(options.url);
+                cb({ id: opened.length });
+            },
             remove: (id, cb) => {
                 if (cb) cb();
             },
@@ -124,6 +138,32 @@ function loadColdWorker(networkId) {
 
     require("../src/background/index");
 
+    // The user approves the prompt the request opened, as the popup does: a
+    // decision on the port named for the approval, from the extension's own
+    // page.
+    function approvePrompt() {
+        const id = new URL(opened[opened.length - 1]).searchParams.get(
+            "approval",
+        );
+        let onDecision = null;
+        const port = {
+            name: "approval:" + id,
+            sender: { url: "chrome-extension://autistmask/src/popup/" },
+            onMessage: {
+                addListener: (fn) => {
+                    onDecision = fn;
+                },
+            },
+            onDisconnect: { addListener: () => {} },
+        };
+        connectListener(port);
+        onDecision(
+            { type: "AUTISTMASK_APPROVAL_DECISION", approved: true },
+            port,
+        );
+    }
+
+    // A connected site asks for `chainId`, and the user approves it.
     async function switchChain(chainId) {
         let result = null;
         messageListener(
@@ -138,6 +178,8 @@ function loadColdWorker(networkId) {
             },
         );
         await settle();
+        approvePrompt();
+        await settle();
         return result;
     }
 

tests/deleteWalletLostPassword.test.js

@@ -253,7 +253,7 @@ describe("reaching the screen", () => {
         const { decryptWithPassword } = require("../src/shared/vault");
         decryptWithPassword.mockRejectedValue(new Error("nope"));
         await click("btn-delete-wallet-confirm");
-        expect(node("delete-wallet-flash").textContent).toBe(
+        expect(node("delete-wallet-password-error").textContent).toBe(
             "That password is incorrect. Please try again.",
         );
     });

tests/e2e/firefox/driver.js

@@ -279,12 +279,18 @@ class Driver {
 
     // Shown means shown: in the popup a view is switched by toggling a
     // "hidden" class, and an element that is present but collapsed is not
-    // the thing a test means by visible.
+    // the thing a test means by visible. Until the page's stylesheet has
+    // applied that class hides nothing and every view lays out, so the page
+    // must also have finished loading, which it does only after its
+    // stylesheet, and neither the element nor anything enclosing it may
+    // carry the class (https://git.eeqj.de/sneak/AutistMask/issues/502).
     async waitVisible(selector, timeout = DEFAULT_WAIT_MS) {
         return this.waitFor(
             "selector " + selector + " to be visible",
             `const el = document.querySelector(arguments[0]);
-             if (!el) return false;
+             if (document.readyState !== "complete" || !el) return false;
+             if (el.closest(".hidden")) return false;
+             if (getComputedStyle(el).visibility !== "visible") return false;
              const r = el.getBoundingClientRect();
              return r.width > 0 && r.height > 0;`,
             [selector],

tests/e2e/firefox/run.js

@@ -63,6 +63,7 @@ const {
 const { ConsoleErrors, EXTENSION_ORIGIN, start, sleep } = require("./driver");
 const { startDappServer } = require("./dapp");
 const { STUB_COUNTERPARTY } = require("../network");
+const { NETWORKS } = require("../../../src/shared/networks");
 const {
     STATE_SCHEMA_VERSION,
     stateProblem,
@@ -684,6 +685,159 @@ step(
     },
 );
 
+// The network fields of the stored record, read on the popup page, the one
+// moz-extension:// document the suite has open.
+async function storedNetwork(env) {
+    const d = env.driver;
+    await d.switchToWindow(env.popupWindow);
+    const stored = await d.executeAsync(
+        `const done = arguments[arguments.length - 1];
+         const api = typeof browser !== "undefined" ? browser : chrome;
+         Promise.resolve(api.storage.local.get("autistmask")).then(
+             (r) => done({
+                 networkId: r.autistmask.networkId,
+                 rpcUrl: r.autistmask.rpcUrl,
+                 blockscoutUrl: r.autistmask.blockscoutUrl,
+             }),
+             (e) => done({ error: String((e && e.message) || e) }),
+         );`,
+    );
+    assert(
+        stored && !stored.error,
+        "could not read the stored network: " + (stored && stored.error),
+    );
+    return stored;
+}
+
+// Every chainChanged event the test page has been sent, waiting up to
+// `timeout` for there to be `count` of them: the background sends the event
+// alongside its answer to the request, so it can arrive just after it. Leaves
+// the driver on the page.
+async function chainChangedEvents(env, count = 0, timeout = 5000) {
+    const d = env.driver;
+    await d.switchToWindow(env.dappWindow);
+    const deadline = Date.now() + timeout;
+    for (;;) {
+        const events = (await dappMessages(d, "AUTISTMASK_EVENT")).filter(
+            (m) => m.eventName === "chainChanged",
+        );
+        if (events.length >= count || Date.now() > deadline) return events;
+        await sleep(100);
+    }
+}
+
+// Ask, from the page, to switch from network `from` to network `to`, and
+// return the prompt that opens, checked to name the site and both networks.
+// Leaves the driver on the prompt.
+async function openNetworkPrompt(env, key, from, to) {
+    const d = env.driver;
+    await d.switchToWindow(env.dappWindow);
+    await startRequest(d, key, "wallet_switchEthereumChain", [
+        { chainId: to.chainId },
+    ]);
+    const popup = await waitForApprovalWindow(d);
+    await d.switchToWindow(popup);
+    await d.waitVisible("#view-approve-network");
+    const screen = {
+        origin: await d.text("#approve-network-origin"),
+        current: await d.text("#approve-network-current"),
+        requested: await d.text("#approve-network-requested"),
+    };
+    assert(
+        isDeepStrictEqual(screen, {
+            origin: env.server.origin,
+            current: from.name,
+            requested: to.name,
+        }),
+        "the network switch prompt shows " + JSON.stringify(screen),
+    );
+    return popup;
+}
+
+// Only the user switches the network. A connected site's request opens a
+// prompt, and until the user approves it the stored network does not move and
+// no page is told it did (https://git.eeqj.de/sneak/AutistMask/issues/408).
+// The wallet goes back to mainnet the same way at the end, for the transaction
+// step after this one.
+step(
+    "a site's network switch changes nothing until the user approves it",
+    async (env) => {
+        const d = env.driver;
+        const { mainnet, sepolia } = NETWORKS;
+        const before = await storedNetwork(env);
+        assert(
+            before.networkId === "mainnet",
+            "this step starts on mainnet, not on " + before.networkId,
+        );
+        const eventsBefore = (await chainChangedEvents(env)).length;
+
+        const rejected = await openNetworkPrompt(
+            env,
+            "switch-reject",
+            mainnet,
+            sepolia,
+        );
+        assert(
+            isDeepStrictEqual(await storedNetwork(env), before),
+            "the network moved while its prompt was still open",
+        );
+        // Nothing else closes this window, so a click that did not land
+        // leaves the request unanswered and the assertion below fails.
+        await d.switchToWindow(rejected);
+        await d.click("#btn-reject-network");
+        await d.switchToWindow(env.dappWindow);
+        await assertUserRejection(
+            d,
+            "switch-reject",
+            "the network switch rejection",
+        );
+        assert(
+            isDeepStrictEqual(await storedNetwork(env), before),
+            "a rejected network switch moved the network",
+        );
+        assert(
+            (await chainChangedEvents(env)).length === eventsBefore,
+            "a rejected network switch told the page the chain changed",
+        );
+
+        await openNetworkPrompt(env, "switch-approve", mainnet, sepolia);
+        await d.click("#btn-approve-network");
+        await d.switchToWindow(env.dappWindow);
+        let outcome = await settleRequest(d, "switch-approve");
+        assert(
+            outcome.settled === "resolved" && outcome.result === null,
+            "the approved network switch did not resolve: " +
+                JSON.stringify(outcome),
+        );
+        assert(
+            (await storedNetwork(env)).networkId === "sepolia",
+            "the approved network switch did not move the network",
+        );
+        const events = await chainChangedEvents(env, eventsBefore + 1);
+        assert(
+            events.length === eventsBefore + 1 &&
+                events[events.length - 1].data === sepolia.chainId,
+            "the page was not told of the approved switch: " +
+                JSON.stringify(events),
+        );
+
+        await openNetworkPrompt(env, "switch-restore", sepolia, mainnet);
+        await d.click("#btn-approve-network");
+        await d.switchToWindow(env.dappWindow);
+        outcome = await settleRequest(d, "switch-restore");
+        assert(
+            outcome.settled === "resolved",
+            "switching back to mainnet did not resolve: " +
+                JSON.stringify(outcome),
+        );
+        assert(
+            isDeepStrictEqual(await storedNetwork(env), before),
+            "switching back did not restore the mainnet network and endpoints",
+        );
+        await d.switchToWindow(env.dappWindow);
+    },
+);
+
 step(
     "eth_sendTransaction shows the transaction and returns its hash",
     async (env) => {
@@ -854,37 +1008,6 @@ step(
 
 // ------------------------------------------------------------- runner
 
-// Uncaught extension errors that are known, tracked and deliberately
-// tolerated, in the same spirit as ALLOWED_ERRORS in tests/e2e/harness.js:
-// every entry names the issue that will delete it, and every occurrence is
-// still printed, so tolerating one is visible in the log rather than silent.
-// This is the only concession in an otherwise zero-tolerance policy.
-const ALLOWED_ERRORS = [
-    {
-        // The site-connection buttons in src/popup/views/approval.js send
-        // their decision and call window.close() on the next line. Firefox's
-        // BaseContext.wrapPromise reports, through Cu.reportError, any
-        // extension-API promise that settles after its context unloaded —
-        // whether or not the caller attached a handler, so notify()'s catch
-        // cannot suppress it.
-        //
-        // Pre-existing, and not introduced by the promise shim: the send was
-        // already unawaited, and this suite is merely the first thing to
-        // drive that window on Firefox. It is the same teardown ordering as
-        // the issue below, whose fix — making the outcome independent of when
-        // the popup closes — removes this entry with it.
-        pattern: /Promise (?:resolved|rejected) after context unloaded/,
-        source: /\/src\/popup\/index\.js$/,
-        issue: "https://git.eeqj.de/sneak/AutistMask/issues/275",
-    },
-];
-
-function allowedFor(e) {
-    return ALLOWED_ERRORS.find(
-        (a) => a.pattern.test(e.msg) && a.source.test(e.src),
-    );
-}
-
 function formatError(e) {
     return (
         e.msg + " (" + e.src + ":" + e.line + (e.cat ? ", " + e.cat : "") + ")"
@@ -1001,20 +1124,6 @@ async function main() {
                 installFailure = null;
             }
 
-            // Tolerated errors are set aside, never dropped: each one is
-            // printed with the issue that keeps it on the list, so the
-            // concession stays in the run output.
-            const tolerated = found.filter((e) => allowedFor(e));
-            found = found.filter((e) => !allowedFor(e));
-            for (const e of tolerated) {
-                console.log(
-                    "# tolerated (" +
-                        allowedFor(e).issue +
-                        "): " +
-                        formatError(e),
-                );
-            }
-
             // Any uncaught error from an extension source fails the step
             // that provoked it, whether or not its assertions passed.
             if (!failure && found.length > 0) {
@@ -1039,13 +1148,7 @@ async function main() {
         // blamed on any one step, but they are still reported and they
         // still fail the run.
         await sleep(1000);
-        const trailingAll = await errors.take();
+        const trailing = await errors.take();
-        for (const e of trailingAll.filter((x) => allowedFor(x))) {
-            console.log(
-                "# tolerated (" + allowedFor(e).issue + "): " + formatError(e),
-            );
-        }
-        const trailing = trailingAll.filter((e) => !allowedFor(e));
         console.log(
             "# " +
                 (steps.length - failed) +

tests/e2e/harness.js

@@ -333,8 +333,33 @@ async function launch(routeOpts) {
 
 const PASSWORD = "e2e-harness-password";
 
+// Waits until the page shows `selector`, not only until it lays out. Until the
+// page's stylesheet has applied, the `hidden` class that showView() keeps on
+// every view but the current one hides nothing and every view lays out, so a
+// test could read a screen before the page's script had filled it
+// (https://git.eeqj.de/sneak/AutistMask/issues/502). So the page must also
+// have finished loading, which it does only after its stylesheet, and neither
+// the element nor anything enclosing it may carry `hidden`. Polled on a timer:
+// animation frames are not guaranteed to a window that is not in front.
 async function visible(page, selector, timeout = 15000) {
-    await page.waitForSelector(selector, { state: "visible", timeout });
+    await page
+        .waitForFunction(
+            (sel) => {
+                const el = document.querySelector(sel);
+                if (document.readyState !== "complete" || !el) return false;
+                if (el.closest(".hidden")) return false;
+                if (getComputedStyle(el).visibility !== "visible") return false;
+                const r = el.getBoundingClientRect();
+                return r.width > 0 && r.height > 0;
+            },
+            selector,
+            { polling: 50, timeout },
+        )
+        .catch((e) => {
+            throw new Error(
+                "the page did not show " + selector + ": " + e.message,
+            );
+        });
 }
 
 // An empty WebAssembly module: magic number and version header, no

tests/e2e/run.js

@@ -809,7 +809,7 @@ async function secretScreenState(page, view) {
     return page.evaluate(
         (v) => ({
             value: document.getElementById(v + "-value").textContent,
-            error: document.getElementById(v + "-flash").textContent,
+            error: document.getElementById(v + "-password-error").textContent,
             html: document.getElementById("view-" + v).innerHTML,
             resultHidden: document
                 .getElementById(v + "-result")
@@ -906,7 +906,8 @@ test("a wrong password reveals nothing (#161)", async (env) => {
     await env.page.click("#btn-show-phrase-reveal");
     await env.page.waitForFunction(
         () =>
-            document.getElementById("show-phrase-flash").textContent.length > 0,
+            document.getElementById("show-phrase-password-error").textContent
+                .length > 0,
         null,
         { timeout: 60000 },
     );
@@ -1993,13 +1994,14 @@ test("an over-long flash message keeps to one line (#252)", async (env) => {
 
 // Every screen that asks for a password reserves room for one line of error.
 // The two on the dApp approval screens also have a border and padding, which
-// that reserved height has to cover too.
+// that reserved height has to cover too. The add wallet screen's line sits
+// beside its button rather than above it, and has its own test below.
 const PASSWORD_ERROR_CONTAINERS = [
     "approve-tx-error",
     "approve-sign-error",
-    "export-privkey-flash",
+    "export-privkey-password-error",
-    "show-phrase-flash",
+    "show-phrase-password-error",
-    "delete-wallet-flash",
+    "delete-wallet-password-error",
     "confirm-tx-password-error",
 ];
 
@@ -2064,6 +2066,107 @@ test("a password error moves nothing on any screen (#297)", async (env) => {
     }
 });
 
+// ------------------------------------------ add wallet Import button (#493)
+
+// At 360x600 the add wallet screen's Import button already starts near the
+// bottom of the popup, so its password error line sits beside the button
+// rather than above it. Measures the button and the line empty and again
+// filled with the longest error addWallet.js puts there. Runs in the page.
+function measureImportButton() {
+    const button = document.getElementById("btn-add-wallet-confirm");
+    const line = document.getElementById("add-wallet-password-error");
+    const measure = () => {
+        const b = button.getBoundingClientRect();
+        const l = line.getBoundingClientRect();
+        return {
+            buttonTop: b.top + window.scrollY,
+            buttonBottom: b.bottom + window.scrollY,
+            lineTop: l.top + window.scrollY,
+            lineBottom: l.bottom + window.scrollY,
+        };
+    };
+    const empty = measure();
+    line.textContent = "Password must be at least 12 characters.";
+    line.style.visibility = "visible";
+    const filled = measure();
+    line.textContent = "";
+    line.style.visibility = "hidden";
+    return { empty, filled };
+}
+
+test("the add wallet password error leaves Import where it was (#493)", async (env) => {
+    const page = await openPopup(env.ctx, env.popupUrl);
+    try {
+        await page.setViewportSize(POPUP_VIEWPORT);
+        // Brought up by toggling classes, as in the test above. The note
+        // addWallet.js shows once a wallet exists is the only part of the
+        // screen that differs between the first wallet and a later one.
+        await page.evaluate(() => {
+            const screen = document.getElementById("view-add-wallet");
+            for (const view of document.querySelectorAll(".view")) {
+                view.classList.toggle("hidden", view !== screen);
+            }
+        });
+        for (const walletExists of [false, true]) {
+            await page.evaluate(
+                (shown) =>
+                    document
+                        .getElementById("add-wallet-separate-password-note")
+                        .classList.toggle("hidden", !shown),
+                walletExists,
+            );
+            for (const tab of ["tab-mnemonic", "tab-privkey", "tab-xprv"]) {
+                await page.click("#" + tab);
+                const { empty, filled } =
+                    await page.evaluate(measureImportButton);
+                const where =
+                    "#" +
+                    tab +
+                    (walletExists
+                        ? " with a wallet already added"
+                        : " for the first wallet");
+                // Printed pass or fail, as the dust threshold test does.
+                console.log(
+                    "# add wallet Import top, " +
+                        where +
+                        ": " +
+                        empty.buttonTop +
+                        "px",
+                );
+                for (const m of [empty, filled]) {
+                    assert(
+                        m.lineTop >= m.buttonTop &&
+                            m.lineBottom <= m.buttonBottom,
+                        "the error line on " +
+                            where +
+                            " does not fit beside Import, so it adds height: " +
+                            JSON.stringify(m),
+                    );
+                }
+                assert(
+                    filled.buttonTop === empty.buttonTop,
+                    "Import moved " +
+                        (filled.buttonTop - empty.buttonTop) +
+                        "px when the error appeared on " +
+                        where,
+                );
+                if (!walletExists) {
+                    assert(
+                        empty.buttonTop < POPUP_VIEWPORT.height,
+                        "Import starts at " +
+                            empty.buttonTop +
+                            "px on " +
+                            where +
+                            ", below the fold",
+                    );
+                }
+            }
+        }
+    } finally {
+        await page.close();
+    }
+});
+
 // --------------------------------------------- confirmation screen (#238)
 //
 // The screen that decides what gets signed. The arithmetic underneath it
@@ -3396,7 +3499,7 @@ async function closeApprovalPages(ctx) {
 }
 
 // Click a button whose own handler closes the window it lives in — every
-// Reject, and Allow on the site prompt.
+// Reject, Allow on the site prompt, and Switch on the network switch prompt.
 //
 // page.click() dispatches the click and then waits for the renderer to
 // acknowledge it, and a page torn down by the handler never gets to. The
@@ -3411,12 +3514,13 @@ async function closeApprovalPages(ctx) {
 //   #btn-reject-sign, #btn-reject-tx — their disconnect leaves the approval
 //     pending, so a click that never landed leaves the dApp promise unsettled
 //     and the assertion after the call fails on its own.
-//   #btn-approve — only a decision resolves the promise, and a swallowed click
+//   #btn-approve, #btn-approve-network — only a decision resolves the promise,
-//     cannot produce settled === "resolved".
+//     and a swallowed click cannot produce settled === "resolved".
-//   #btn-reject on the site prompt — NOT self-proving. A page that went away
+//   #btn-reject on the site prompt, #btn-reject-network — NOT self-proving. A
-//     without the click landing disconnects the approval port, the background
+//     page that went away without the click landing disconnects the approval
-//     settles that as 4001, and 4001 is exactly what assertUserRejection
+//     port, the background settles that as 4001, and 4001 is exactly what
-//     accepts. Both call sites arm the click trace below and assert it.
+//     assertUserRejection accepts. Every call site arms the click trace below
+//     and asserts it.
 //
 // A button that is missing or unclickable raises a different error, which is
 // rethrown.
@@ -4286,6 +4390,190 @@ test("a prompt raised while another approval window has focus opens its own (#29
     await assertUserRejection(env.dapp, "focus-sign", "the sign prompt");
 });
 
+// The network fields of the stored record.
+async function storedNetwork(page) {
+    const s = await storedRecord(page);
+    return {
+        networkId: s.networkId,
+        rpcUrl: s.rpcUrl,
+        blockscoutUrl: s.blockscoutUrl,
+    };
+}
+
+// Every chainChanged event the test page has been sent, waiting up to
+// `timeout` for there to be `count` of them: the background sends the event
+// alongside its answer to the request, so it can arrive just after it.
+async function chainChangedEvents(page, count = 0, timeout = 5000) {
+    const deadline = Date.now() + timeout;
+    for (;;) {
+        const events = (await dappMessages(page, "AUTISTMASK_EVENT")).filter(
+            (m) => m.eventName === "chainChanged",
+        );
+        if (events.length >= count || Date.now() > deadline) return events;
+        await sleep(50);
+    }
+}
+
+// Ask, from the test page, to switch from network `from` to network `to`, and
+// return the prompt that opens, checked to name the site and both networks.
+async function openNetworkPrompt(env, key, from, to) {
+    await startRequest(env.dapp, key, "wallet_switchEthereumChain", [
+        { chainId: to.chainId },
+    ]);
+    const popup = await waitForApprovalWindow(env.ctx);
+    await visible(popup, "#view-approve-network");
+    const screen = await popup.evaluate(() => ({
+        origin: document.getElementById("approve-network-origin").textContent,
+        current: document.getElementById("approve-network-current").textContent,
+        requested: document.getElementById("approve-network-requested")
+            .textContent,
+    }));
+    assert(
+        isDeepStrictEqual(screen, {
+            origin: DAPP_ORIGIN,
+            current: from.name,
+            requested: to.name,
+        }),
+        "the network switch prompt shows " + JSON.stringify(screen),
+    );
+    return popup;
+}
+
+// Only the user switches the network. A connected site's request opens a
+// prompt, and until the user approves it the stored network does not move and
+// no page is told it did (https://git.eeqj.de/sneak/AutistMask/issues/408).
+// The wallet goes back to mainnet the same way at the end, for the tests after
+// this one.
+test("a site's network switch changes nothing until the user approves it (#408)", async (env) => {
+    const { mainnet, sepolia } = NETWORKS;
+    const before = await storedNetwork(env.page);
+    assert(
+        before.networkId === "mainnet",
+        "this test starts on mainnet, not on " + before.networkId,
+    );
+    const eventsBefore = (await chainChangedEvents(env.dapp)).length;
+
+    const rejected = await openNetworkPrompt(
+        env,
+        "switch-reject",
+        mainnet,
+        sepolia,
+    );
+    try {
+        assert(
+            isDeepStrictEqual(await storedNetwork(env.page), before),
+            "the network moved while its prompt was still open",
+        );
+        // Closing the prompt unanswered is also a rejection, so the click
+        // itself is witnessed.
+        await armClickTrace(env, rejected, "#btn-reject-network");
+        await clickAndClose(rejected, "#btn-reject-network");
+        await assertClickLanded(env, "#btn-reject-network");
+        await assertUserRejection(
+            env.dapp,
+            "switch-reject",
+            "the network switch rejection",
+        );
+    } finally {
+        await closeApprovalPages(env.ctx);
+    }
+    assert(
+        isDeepStrictEqual(await storedNetwork(env.page), before),
+        "a rejected network switch moved the network",
+    );
+    assert(
+        (await chainChangedEvents(env.dapp)).length === eventsBefore,
+        "a rejected network switch told the page the chain changed",
+    );
+
+    const approved = await openNetworkPrompt(
+        env,
+        "switch-approve",
+        mainnet,
+        sepolia,
+    );
+    let outcome;
+    try {
+        await clickAndClose(approved, "#btn-approve-network");
+        outcome = await settleRequest(env.dapp, "switch-approve");
+    } finally {
+        await closeApprovalPages(env.ctx);
+    }
+    assert(
+        outcome.settled === "resolved" && outcome.result === null,
+        "the approved network switch did not resolve: " +
+            JSON.stringify(outcome),
+    );
+    assert(
+        (await storedNetwork(env.page)).networkId === "sepolia",
+        "the approved network switch did not move the network",
+    );
+    const events = await chainChangedEvents(env.dapp, eventsBefore + 1);
+    assert(
+        events.length === eventsBefore + 1 &&
+            events[events.length - 1].data === sepolia.chainId,
+        "the page was not told of the approved switch: " +
+            JSON.stringify(events),
+    );
+
+    const restored = await openNetworkPrompt(
+        env,
+        "switch-restore",
+        sepolia,
+        mainnet,
+    );
+    try {
+        await clickAndClose(restored, "#btn-approve-network");
+        outcome = await settleRequest(env.dapp, "switch-restore");
+    } finally {
+        await closeApprovalPages(env.ctx);
+    }
+    assert(
+        outcome.settled === "resolved",
+        "switching back to mainnet did not resolve: " + JSON.stringify(outcome),
+    );
+    assert(
+        isDeepStrictEqual(await storedNetwork(env.page), before),
+        "switching back did not restore the mainnet network and endpoints",
+    );
+});
+
+// Switching the network in Settings tells the page too, as an approved site
+// request does (https://git.eeqj.de/sneak/AutistMask/issues/500). The wallet
+// goes back to mainnet the same way at the end.
+test("a network switch in Settings tells the page (#500)", async (env) => {
+    const { mainnet, sepolia } = NETWORKS;
+    const before = await storedNetwork(env.page);
+    assert(
+        before.networkId === "mainnet",
+        "this test starts on mainnet, not on " + before.networkId,
+    );
+    const eventsBefore = (await chainChangedEvents(env.dapp)).length;
+    await openSettings(env.page);
+
+    await env.page.selectOption("#settings-network", "sepolia");
+    let events = await chainChangedEvents(env.dapp, eventsBefore + 1);
+    assert(
+        events.length === eventsBefore + 1 &&
+            events[events.length - 1].data === sepolia.chainId,
+        "the page was not told of the switch to Sepolia: " +
+            JSON.stringify(events),
+    );
+
+    await env.page.selectOption("#settings-network", "mainnet");
+    events = await chainChangedEvents(env.dapp, eventsBefore + 2);
+    assert(
+        events.length === eventsBefore + 2 &&
+            events[events.length - 1].data === mainnet.chainId,
+        "the page was not told of the switch back to mainnet: " +
+            JSON.stringify(events),
+    );
+    assert(
+        isDeepStrictEqual(await storedNetwork(env.page), before),
+        "switching back did not restore the mainnet network and endpoints",
+    );
+});
+
 // The closing pass over both boundaries at once. Every message the section
 // put on either channel is re-read here and required to be free of the
 // password — and required to be there at all, method by method, so the

tests/exportPrivkey.test.js

@@ -207,7 +207,7 @@ describe("a decrypt still running when the screen is left", () => {
     });
 
     // Same hole on the failure path: a wrong-password error written after
-    // the wipe would restore the flash line on a screen the user has left.
+    // the wipe would restore the error line on a screen the user has left.
     test("never writes the failure message either", async () => {
         const { helpers, vault, exportPrivkey } = load();
         exportPrivkey.show(0, 0);
@@ -217,8 +217,10 @@ describe("a decrypt still running when the screen is left", () => {
         reveal.reject(new Error("decryption failed"));
         await reveal.pending;
 
-        expect(node("export-privkey-flash").textContent).toBe("");
+        expect(node("export-privkey-password-error").textContent).toBe("");
-        expect(node("export-privkey-flash").style.visibility).toBe("hidden");
+        expect(node("export-privkey-password-error").style.visibility).toBe(
+            "hidden",
+        );
     });
 });
 
@@ -260,7 +262,7 @@ describe("a reveal that is not interrupted", () => {
         await reveal.pending;
 
         expect(node("export-privkey-value").textContent).toBe("");
-        expect(node("export-privkey-flash").textContent).toBe(
+        expect(node("export-privkey-password-error").textContent).toBe(
             "That password is incorrect. Please try again.",
         );
     });

tests/nativeCurrency.test.js

@@ -345,10 +345,10 @@ describe.each([
 });
 
 // A transaction's value and fee are in the native currency of the network the
-// transaction is on, which need not be the active one. A site can switch the
+// transaction is on, which need not be the active one. The active network can
-// active network after its transaction is prepared and back before it is
+// change, in Settings or when the user approves a site's request, after a
-// signed, and a popup opened after a switch shows a sent or listed transaction
+// transaction is prepared and change back before it is signed, and a popup
-// again. The wallet's balances follow the active network; these do not.
+// opened after a switch shows a sent or listed transaction again. The wallet's balances follow the active network; these do not.
 describe.each([
     ["mainnet", "sepolia", "ETH"],
     ["sepolia", "mainnet", "SepoliaETH"],

tests/passwordErrorLines.test.js

@@ -0,0 +1,159 @@
+// Every screen that asks for a password shows a password error the same way:
+// through showError() and hideError() in src/popup/views/helpers.js, in a
+// fixed-height error line below the password field, and never in the flash
+// line at the top of the popup
+// (https://git.eeqj.de/sneak/AutistMask/issues/493). These boot the real popup
+// over src/popup/index.html, so each error line has to exist in the markup,
+// and check that the error appears in it and clears again.
+
+jest.mock("../src/shared/vault", () => ({
+    decryptWithPassword: jest.fn(),
+    encryptWithPassword: jest.fn(),
+}));
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+const PASSWORD = "correct horse battery staple";
+const WRONG_PASSWORD = "That password is incorrect. Please try again.";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The error line as the user sees it.
+function errorLine(page, id) {
+    return {
+        inMarkup: page.document.authoredIds.has(id),
+        text: page.text(id),
+        visibility: page.node(id).style.visibility,
+    };
+}
+
+function shown(text) {
+    return { inMarkup: true, text, visibility: "visible" };
+}
+
+const cleared = { inMarkup: true, text: "", visibility: "hidden" };
+
+describe("the add wallet screen", () => {
+    const ERROR = "add-wallet-password-error";
+
+    // First run: Welcome, "Add wallet", then the die for a valid phrase.
+    async function openAddWallet() {
+        const page = await bootPopup(undefined);
+        await page.click("btn-welcome-add");
+        await page.click("btn-generate-phrase");
+        return page;
+    }
+
+    function setPasswords(page, password, confirm) {
+        page.node("add-wallet-password").value = password;
+        page.node("add-wallet-password-confirm").value = confirm;
+    }
+
+    test("shows a password problem below the password fields, and clears it on the next press", async () => {
+        const page = await openAddWallet();
+        setPasswords(page, "short", "short");
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(
+            shown("Password must be at least 12 characters."),
+        );
+        expect(page.text("flash-msg")).toBe("");
+
+        // The password is fixed and the phrase emptied: the password error
+        // goes, and the phrase problem is still reported in the flash line.
+        setPasswords(page, PASSWORD, PASSWORD);
+        page.node("wallet-mnemonic").value = "";
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(cleared);
+        expect(page.text("flash-msg")).toBe(
+            "Enter a recovery phrase, or press the die.",
+        );
+
+        // Leaving clears the flash line and stops its timer, which would
+        // otherwise fire after this page is gone.
+        await page.click("btn-add-wallet-back");
+    });
+
+    test("clears the error when the screen is shown again", async () => {
+        const page = await openAddWallet();
+        setPasswords(page, PASSWORD, PASSWORD + " typo");
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(
+            shown("Passwords do not match."),
+        );
+
+        await page.click("btn-add-wallet-back");
+        await page.click("btn-welcome-add");
+        expect(errorLine(page, ERROR)).toEqual(cleared);
+    });
+});
+
+describe.each([
+    {
+        screen: "the private key export screen",
+        open: () => require("../src/popup/views/exportPrivkey").show(0, 0),
+        field: "export-privkey-password",
+        button: "btn-export-privkey-confirm",
+        error: "export-privkey-password-error",
+    },
+    {
+        screen: "the recovery phrase screen",
+        open: () => require("../src/popup/views/showPhrase").show(0),
+        field: "show-phrase-password",
+        button: "btn-show-phrase-reveal",
+        error: "show-phrase-password-error",
+    },
+    {
+        screen: "the delete wallet screen",
+        open: () => require("../src/popup/views/deleteWallet").show(0),
+        field: "delete-wallet-password",
+        button: "btn-delete-wallet-confirm",
+        error: "delete-wallet-password-error",
+    },
+])("$screen", ({ open, field, button, error }) => {
+    // Opens the screen and enters a password the vault rejects.
+    async function failedAttempt() {
+        const page = await bootPopup(unversionedValidProfile());
+        open();
+        const { decryptWithPassword } = require("../src/shared/vault");
+        decryptWithPassword.mockRejectedValue(new Error("wrong password"));
+        page.node(field).value = "not the password";
+        await page.click(button);
+        return { page, decryptWithPassword };
+    }
+
+    test("shows a wrong password below the password field", async () => {
+        const { page } = await failedAttempt();
+        expect(errorLine(page, error)).toEqual(shown(WRONG_PASSWORD));
+    });
+
+    test("clears the error while the next password is checked", async () => {
+        const { page, decryptWithPassword } = await failedAttempt();
+        let rejectDecrypt;
+        decryptWithPassword.mockReturnValue(
+            new Promise((resolve, reject) => {
+                rejectDecrypt = reject;
+            }),
+        );
+
+        page.node(field).value = "another guess";
+        const pressed = page.click(button);
+        await page.settle();
+        expect(errorLine(page, error)).toEqual(cleared);
+
+        rejectDecrypt(new Error("wrong password"));
+        await pressed;
+        expect(errorLine(page, error)).toEqual(shown(WRONG_PASSWORD));
+    });
+
+    test("clears the error when the screen is shown again", async () => {
+        const { page } = await failedAttempt();
+        open();
+        expect(errorLine(page, error)).toEqual(cleared);
+    });
+});

tests/persistedFieldContract.test.js

@@ -49,22 +49,37 @@
 // every path a stored record takes, and the difference is the whole of what
 // this file does not cover:
 //
-//   - Only the values in the table, in the SLOT arrangement below: four value
+//   - Only the values in the table, in the SLOT arrangement below. On the
-//     combinations per view, not the product of twelve fields. A dereference
+//     restore path the twelve fields the router does not read are corrupted
-//     reached only under a pairing no slot produces is not driven at all.
+//     together, every field on the same slot, so a view gets four value
-//   - Only what a stored record reaches by ITSELF. A view only forward
+//     combinations of them, not their product. A branch entered only when one
-//     navigation opens, and anything behind a click, is not driven.
+//     of them is truthy and another falsy is reached only where the falsy
-//   - Nothing about the paths a HEALTHY profile takes, which is most of the
+//     slot happens to pair a field that cannot be falsy with one that is.
-//     popup. This file is a floor under one defect class, not a proof about
+//     Each field the router reads is corrupted alone, over an otherwise
-//     the renderers.
+//     well-formed record.
+//   - Only what a stored record reaches by ITSELF, as the boot renders it. A
+//     view only forward navigation opens, anything behind a click, and
+//     anything behind a timer (bootPopup() records every interval, and this
+//     file never runs one) is not driven.
+//   - Of the paths a HEALTHY profile takes, only its boot onto each
+//     restorable view ("the base profile the sweep corrupts" below). The rest
+//     of the popup is not covered: this file is a floor under one defect
+//     class, not a proof about the renderers.
 //
-// Within that boundary it is unconditional: if one of these boots leaves the
+// Within that boundary it is unconditional: if a boot that corrupts a field
-// popup unhealthy or off the view it stored, this file goes red — including
+// leaves the popup unhealthy, this file goes red — including when it takes
-// when it takes two corrupted fields at once, because the verdict is the
+// two corrupted fields at once, because the verdict is the combined boot
-// combined boot itself and the per-field re-boot below can only decorate the
+// itself and the per-field re-boot below can only decorate the message. That
-// message. That last part is the one thing an earlier version got wrong: it
+// last part is the one thing an earlier version got wrong: it asserted on the
-// asserted on the per-field list, so an observed dead popup that no single
+// per-field list, so an observed dead popup that no single field reproduced
-// field reproduced was reported green.
+// was reported green.
+//
+// Where the popup lands is held for some of those boots and not others. The
+// combined boot must land on the view it stored, and each `hostileRestore`
+// value must land on its view, or fall back to Home, as its entry declares.
+// The boots in "a hostile routing value restoring onto" are held to health
+// alone, because a value in a field the router reads legitimately changes
+// which view renders; so are the boots onto Home, which store no view.
 //
 // Booting every field separately at every value would be several hundred boots
 // and most of the suite's budget; this is forty-four. Widening it further is
@@ -128,7 +143,11 @@ const sweptValues = (row) => [...row.hostile, ...(row.falsy || [])];
 // list short and pointed. `floorOnly` is extra values checked against the
 // floor alone, which is pure and free. `hostileRestore` is extra values driven
 // through the restore path only, for a value that means nothing until a
-// particular branch's gate has let it past.
+// particular branch's gate has let it past. Each of its entries names the
+// `views` it is driven onto and declares whether the boot lands on them
+// (`restored: true`) or falls back to Home (`restored: false`), so a value
+// written for one renderer cannot stop reaching it unnoticed. A value driven
+// onto every restorable view is written with everyRestorableView() below.
 //
 // `falsy` is the other POLARITY of a swept field, driven for the same reason.
 // It is not a value src/ never writes — for three of these fields it is the
@@ -139,6 +158,23 @@ const sweptValues = (row) => [...row.hostile, ...(row.falsy || [])];
 // falsy value stored under that field comes back TRUTHY from the floor, so no
 // `!state.x` branch is reachable from a stored record at all.
 
+// The `hostileRestore` entries for a value driven onto every restorable view:
+// it falls back to Home on the views listed in `fallsBackOn` and lands on every
+// other one, so a view added to RESTORABLE_VIEWS is driven, and expected to
+// land, without editing the row.
+function everyRestorableView(value, fallsBackOn) {
+    return [
+        { value, views: fallsBackOn, restored: false },
+        {
+            value,
+            views: [...RESTORABLE_VIEWS].filter(
+                (view) => !fallsBackOn.includes(view),
+            ),
+            restored: true,
+        },
+    ];
+}
+
 const CONTRACT = [
     {
         field: "wallets",
@@ -280,28 +316,38 @@ const CONTRACT = [
         kind: KIND.SCALAR,
         // The prototype members are the whole point: `wallets["map"]` is
         // TRUTHY, so hasValidAddress()'s `&&` does not short-circuit and
-        // `.addresses[…]` throws. A stale INTEGER is the safe case.
+        // `.addresses[…]` throws. A stale INTEGER is the safe case and has to
-        hostile: ["map", "__proto__", { a: 1 }],
+        // stay so. 5 is one, out of range for the one wallet in the profile,
+        // and it is also this field's truthy polarity: every other value here
+        // comes back from the floor as null.
+        hostile: ["map", "__proto__", { a: 1 }, 5],
         floorOnly: ["length", "constructor", "toString", "0", -1, 1.5, true],
         holds: isIndexOrNull,
         // SCALAR, and swept anyway: the restore path is precisely why this
         // field gained a floor, so the sweep is the regression guard on it.
         alsoSweep: true,
         routes: true,
-        // A stale INTEGER index, which reaches the restore path by a different
+        // Comes back from the floor as null, which hasValidAddress() reads as
-        // route from the prototype members above — falsy or out of range
+        // nothing selected: the popup falls back to Home on the five views
-        // rather than truthy — and has to keep being the safe case.
+        // that need an address, and lands on every other one.
-        hostileRestore: [{ value: "length" }, { value: 5 }],
+        hostileRestore: everyRestorableView("length", [
+            "address",
+            "address-token",
+            "receive",
+            "transaction",
+            "confirm-tx",
+        ]),
     },
     {
         field: "selectedAddress",
         kind: KIND.SCALAR,
-        hostile: ["map", "__proto__", { a: 1 }],
+        // 5 for the same reason as in selectedWallet: a stale index, and the
+        // one value here still truthy after the floor.
+        hostile: ["map", "__proto__", { a: 1 }, 5],
         floorOnly: ["length", "constructor", "toString", "0", -1, 1.5, true],
         holds: isIndexOrNull,
         alsoSweep: true,
         routes: true,
-        hostileRestore: [{ value: 5 }],
     },
     {
         field: "currentView",
@@ -325,7 +371,9 @@ const CONTRACT = [
         // container shapes below onto every restorable view; hostileRestore
         // adds the records that PASS a branch's gate and then hand its
         // renderer something it dereferences, which is where the entries are
-        // actually decided.
+        // actually decided. The guard refuses each single-view record below,
+        // so each is declared to fall back to Home: one that started landing
+        // would be reaching the renderer it was written against.
         hostile: [42, "notarecord", { a: 1 }, [1, 2]],
         // `structuredClone(saved.viewData || {})`: the container is never falsy
         // in state whatever was stored, so no `!state.viewData` branch exists to
@@ -334,11 +382,20 @@ const CONTRACT = [
         hostileRestore: [
             // success-tx passes on `data.hash`, and renderSuccess() then calls
             // toAddressHtml(d.to) -> addressTitle() -> address.toLowerCase().
-            { value: { hash: "0x1" }, views: ["success-tx"] },
+            {
-            { value: { hash: "0x1", to: 42 }, views: ["success-tx"] },
+                value: { hash: "0x1" },
+                views: ["success-tx"],
+                restored: false,
+            },
+            {
+                value: { hash: "0x1", to: 42 },
+                views: ["success-tx"],
+                restored: false,
+            },
             {
                 value: { hash: "0x1", to: ADDRESS, decoded: { details: 7 } },
                 views: ["success-tx"],
+                restored: false,
             },
             {
                 value: {
@@ -347,12 +404,25 @@ const CONTRACT = [
                     decoded: { details: [{ address: 42 }] },
                 },
                 views: ["success-tx"],
+                restored: false,
             },
             // error-tx passes on `data.message`, same dereference.
-            { value: { message: "boom" }, views: ["error-tx"] },
+            {
-            { value: { message: "boom", to: 42 }, views: ["error-tx"] },
+                value: { message: "boom" },
+                views: ["error-tx"],
+                restored: false,
+            },
+            {
+                value: { message: "boom", to: 42 },
+                views: ["error-tx"],
+                restored: false,
+            },
             // transaction passes on `data.tx`.
-            { value: { tx: { hash: "0x1" } }, views: ["transaction"] },
+            {
+                value: { tx: { hash: "0x1" } },
+                views: ["transaction"],
+                restored: false,
+            },
             {
                 value: {
                     tx: {
@@ -363,9 +433,14 @@ const CONTRACT = [
                     },
                 },
                 views: ["transaction"],
+                restored: false,
             },
             // confirm-tx passes on `data.pendingTx`.
-            { value: { pendingTx: { amount: "1" } }, views: ["confirm-tx"] },
+            {
+                value: { pendingTx: { amount: "1" } },
+                views: ["confirm-tx"],
+                restored: false,
+            },
             {
                 value: {
                     pendingTx: {
@@ -376,6 +451,7 @@ const CONTRACT = [
                     },
                 },
                 views: ["confirm-tx"],
+                restored: false,
             },
             // wait-tx passes on `pendingWait.hash`; restoreWait() has checked
             // the fields below it since it was written, and this is the
@@ -388,20 +464,29 @@ const CONTRACT = [
                     },
                 },
                 views: ["wait-tx"],
+                restored: false,
             },
             // A record that passes EVERY branch's gate at once, driven onto
             // every restorable view: a branch a view does not read must stay
-            // one it does not read, and each renderer must survive the fields
+            // one it does not read. The five views with a viewData branch
-            // another branch left behind.
+            // refuse it; every other one renders it, and must survive the
+            // fields every branch left behind.
+            ...everyRestorableView(
                 {
-                value: {
                     hash: "0x1",
                     message: "boom",
                     tx: { hash: "0x1" },
                     pendingTx: { amount: "1" },
                     pendingWait: { hash: "0x1" },
                 },
-            },
+                [
+                    "confirm-tx",
+                    "transaction",
+                    "wait-tx",
+                    "success-tx",
+                    "error-tx",
+                ],
+            ),
         ],
     },
     {
@@ -583,6 +668,11 @@ const HEALTHY = { errors: [], blank: false };
 // set is all-truthy by construction, so without a falsy slot a dereference
 // behind `if (!state.x)` is never reached on the boot that corrupts x — the
 // same falsy-collapse blind spot the fields below were floored for.
+//
+// Only `hostile` and `falsy` values count. Those go through the sweep below,
+// which covers every restorable view; a `hostileRestore` entry is driven onto
+// only the views it names, so a polarity it alone supplied might reach a single
+// renderer.
 describe("both polarities of every swept field are driven", () => {
     const FALSY_STORED = [0, "", false, null];
     const floored = (field, value) =>
@@ -606,10 +696,9 @@ describe("both polarities of every swept field are driven", () => {
         test(`${row.field}: truthy and falsy`, () => {
             // What the boots below actually drive, floored the way a renderer
             // sees it — not what the row says it drives.
-            const driven = [
+            const driven = sweptValues(row).map((value) =>
-                ...sweptValues(row),
+                floored(row.field, value),
-                ...(row.hostileRestore || []).map((entry) => entry.value),
+            );
-            ].map((value) => floored(row.field, value));
 
             expect({
                 truthy: driven.some((value) => Boolean(value)),
@@ -865,20 +954,27 @@ describe("every field the router does not read, corrupted at once, onto", () =>
 
 // The values that only mean something on the restore path: a viewData that
 // PASSES a branch's gate and then hands its renderer something dereferenced,
-// and the index values whose route through hasValidAddress() differs from the
+// and a selectedWallet the floor turns into nothing selected. Each boot must
-// row's own hostile set.
+// throw nothing and show exactly the view its entry says it lands on: its own,
+// or Home, so a value written for one renderer cannot stop reaching it and
+// still pass.
 describe("a restore-only hostile value onto", () => {
     for (const row of CONTRACT) {
         for (const entry of row.hostileRestore || []) {
-            for (const view of entry.views || RESTORABLE_VIEWS) {
+            for (const view of entry.views) {
                 test(`${view}: ${row.field} = ${JSON.stringify(
                     entry.value,
                 )}`, async () => {
-                    await expect(
+                    const env = await bootPopup(
-                        bootHealth(
                         restoringOnto(view, { [row.field]: entry.value }),
-                        ),
+                    );
-                    ).resolves.toEqual(HEALTHY);
+                    expect({
+                        errors: env.pageErrors,
+                        visible: env.visibleViews(),
+                    }).toEqual({
+                        errors: [],
+                        visible: [entry.restored ? view : "main"],
+                    });
                 });
             }
         }

tests/support/popupBoot.js

@@ -238,6 +238,10 @@ async function settle() {
  * @param {object} [options]
  * @param {object} [options.storage] a storage stub from makeStorageStub(), for
  *     a test that needs to make writes fail or to watch the round trips.
+ * @param {string} [options.search] the page URL's query string, such as
+ *     "?approval=" and an id for the popup opened as an approval window.
+ * @param {object} [options.runtime] members of chrome.runtime that replace the
+ *     stub's own, for a test that has to answer the background's messages.
  * @returns {Promise<object>} handles onto the booted page.
  */
 async function bootPopup(stored, options) {
@@ -281,12 +285,13 @@ async function bootPopup(stored, options) {
             sendMessage: jest.fn(async () => ({})),
             getURL: (p) => "chrome-extension://autistmask/" + p,
             onMessage: { addListener: () => {} },
+            ...(options && options.runtime),
         },
     };
     globalThis.document = document;
     globalThis.window = {
         location: {
-            search: "",
+            search: (options && options.search) || "",
             href: "chrome-extension://autistmask/src/popup/index.html",
             reload: () => reloads.push(Date.now()),
         },