Mark
9ac580869d
Plan-04-04 debug session-2 root cause: the offscreen-console capture
in tests/uat/lib/launch.ts:registerOffscreenConsoleAttach matched zero
offscreen targets across 4 spike runs, creating a critical observability
gap that prevented disambiguation of Plan 04-04 Wave 0 spike failure
mode.
Empirical investigation (tests/uat/spike-diagnose-offscreen-target.ts,
NEW): when chrome.offscreen.createDocument fires, Puppeteer's
`targetcreated` event fires with `type='other'` and `url=''` BEFORE the
CDP target metadata stabilizes. The previous filter (whether
`background_page` or `page`) never matched at event time. By the time
the metadata stabilizes (visible via `browser.targets()`), the
target's type is `'background_page'` (not `'page'` — MV2's
background_page type IS still used by Chrome's CDP for invisible
extension documents, despite MV3 abolishing classic background pages).
Fix:
- Match the offscreen target by URL pattern (load-bearing criterion;
type field is intentionally unchecked because it's unreliable at
targetcreated time).
- Bind to BOTH `targetcreated` AND `targetchanged` events (the latter
fires when the URL stabilizes after navigation).
- Add a `browser.targets()` enumeration race-free safety net for
cases where the offscreen target exists at registration time.
Verification: tests/uat/spike-diagnose-offscreen-target.ts now emits
`(launch: offscreen console attached — url=chrome-extension://.../src/offscreen/index.html)`
followed by `[off:log] [OS:Recorder] Recording started ...` (zero such
lines in any prior spike run).
Test-infra correctness fix; ZERO production source changes. FORBIDDEN_HOOK_STRINGS
inventory unchanged at 12 entries. No new test-only `__MOKOSH_UAT__` symbols.
References:
- .planning/debug/sw-offscreen-persistence-investigation-session-2.md
(session-2 debug note documenting empirical root cause)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Mokosh UAT harness (Plan 01-11)
Puppeteer-driven Node script that runs 14 assertions end-to-end against a real Chrome instance loaded with the Mokosh extension. Replaces Plan 01-09 Task 5's operator-empirical functional verification (the operator retains only step 1 — build — and step 14 — brand/design acceptance).
Quick start
npm run test:uat
This builds dist-test/ (the hook-enabled bundle) and runs the harness.
Exit 0 means all 14 assertions passed. Final line: UAT harness: 14/14 assertions passed.
Local-debug mode
HEADLESS=0 npm run test:uat
Opens a real Chrome window so you can watch the picker auto-accept, the badge transitions, the popup appear, etc.
Developer iteration tricks
# Skip the production build inside assertion 0 (uses existing dist/):
SKIP_PROD_REBUILD=1 npm run test:uat
# Run the harness against an existing dist-test/ (skip npm run build:test):
npx tsx tests/uat/harness.test.ts
Assertion catalog
| # | Title | Bug class | Hook used |
|---|---|---|---|
| 0 | Production bundle has no test-hook leaks | T-1-11-01 | filesystem grep |
| 1 | SW bootstrap → setIdleMode | — | sw.evaluate |
| 2 | Toolbar onClicked-idle → REC + popup | — | triggerExtensionAction |
| 3 | Offscreen displaySurface === monitor | D-15 | __mokoshTest.getCurrentStream |
| 4 | Toolbar onClicked-recording → popup, no new offscreen | — | targets count |
| 5 | SAVE_ARCHIVE → download fires | — | downloads polling |
| 6 | BUG B: simulateUserStop → badge OFF + no recovery notif | b9eeeeb |
dispatchEvent('ended') |
| 7 | RECORDING_ERROR codec-unsupported → ERR + recovery notif | — | sendMessage |
| 8 | BUG A: onStartup → mokosh-startup- notification creates | a881bf0 |
__mokoshTest.handlers.onStartup |
| 9 | Icon file sizes meet floors | Bug A precondition | sw.evaluate(fetch) |
| 10 | Manifest has notifications + 3 icons | Bug A precondition | chrome.runtime.getManifest |
| 11 | 35s recording → segments.length >= 3 | D-13 | __mokoshTest.getSegmentCount |
| 12 | ffprobe on extracted webm exits 0 | Plan 01-08 | jszip + execFile |
| 13 | Archive shape — video + meta.json version match | Plan 01-07 | jszip |
Failure isolation
Single browser, serial assertions, bail on first failure for setup- dependent assertions (assertion 0 abort means refusing to launch a potentially-leaky bundle). Per-assertion bail keeps the diagnostic output unambiguous — see RESEARCH §5 + Plan 01-11 open-question resolution 4.
On failure, the harness dumps the last 30 lines of SW console + last 30 lines of offscreen console (captured live during the run) to stderr BEFORE rethrowing — gives you contextual triage without needing to re- run with debug logging.
Known gotchas
Locale-specific picker auto-accept
The --auto-select-desktop-capture-source=Entire screen Chrome flag
auto-accepts the screen-share picker. The string "Entire screen" is
en_US-specific. If your Chrome is set to a non-English locale, the
picker option label will differ and the auto-accept will silently fail
(picker stays open; assertion 2 times out).
Fallback: switch your Chrome user-data-dir's locale to en_US for
harness runs, OR adjust the launch arg in tests/uat/lib/launch.ts to
match your locale's equivalent string.
dev-dep Chromium binary size
puppeteer pulls a ~150 MB Chromium binary at npm install time. CI
must accept this. Production npm install --omit=dev skips it cleanly.
Xvfb is NOT required
Per Plan 01-11 RESEARCH §3 empirical probes against Chrome 148, the
--headless=new mode handles screen capture without Xvfb on Linux CI
runners. If a future Chrome regresses this, Xvfb :99 & DISPLAY=:99 npm run test:uat is the fallback.
CI runner screen-capture concern
The 35s recording assertion (A11) captures whatever is on screen during that window. CI MUST run the harness in an isolated container with no concurrent workload — see T-1-11-02 in Plan 01-11's threat model.
Real Chrome download (assertion 5 → A12)
The harness configures per-page download behavior via CDP to a fresh
os.tmpdir()/mokosh-uat-downloads-* directory; downloads are NOT
written to your real ~/Downloads. The temp directory is deleted by OS
tmpdir GC.