Mark
c647f61553
Plan 01-11 orchestrator commissioned a research+prototype investigation
into whether full MV3 UAT automation is feasible with the architecture:
extension-internal test page + chrome.runtime.sendMessage bridge +
synthetic MediaStream (canvas-captureStream + getSettings override).
EMPIRICAL VERDICT: feasible BUT plan 01-11 needs architectural revision.
Architectural findings (with proof):
1. DYNAMIC IMPORT BLOCKED IN MV3 SW. Top-of-module
`await import('../test-hooks/sw-hooks')` in src/background/index.ts
silently kills the SW (chunk loads, await never resolves, no
production listeners register, no console output). This is by design
per Chromium docs (es_modules.md) + w3c/webextensions#212. The Plan
01-11 RESEARCH §6 architecture was wrong for the SW side.
Workaround in this prototype: REMOVE the SW-side gated dynamic
import. SW-side test hooks need a different design (see verdict).
2. OFFSCREEN-SIDE DYNAMIC IMPORT WORKS. Offscreen is a DOM document,
not a SW, so top-level await + dynamic import behave normally. The
offscreen-hooks.ts gated import succeeds; installFakeDisplayMedia is
installed eagerly at module load.
3. EXTENSION-INTERNAL PAGE HAS FULL chrome.* SURFACE. Reachable via
chrome-extension://<id>/tests/uat/prototype/extension-page-harness.html
(added as rollup input in vite.test.config.ts). The page can call
chrome.action.getBadgeText, chrome.action.getPopup, chrome.offscreen
.createDocument, chrome.notifications.getAll, chrome.runtime
.sendMessage — everything needed for A6.
4. NO 'tabs' PERMISSION → tab.url IS UNDEFINED. Production
startVideoCapture's `chrome.tabs.query({active:true})` check
(`if (!tab.id || !tab.url) throw`) fails because the manifest lacks
the 'tabs' permission. Prototype workaround: bypass startVideoCapture
by sending START_RECORDING directly to offscreen. The Bug B
contract being tested is independent of how recording starts; it
only depends on the RECORDING_ERROR routing path.
5. SYNTHETIC MEDIASTREAM WORKS. installFakeDisplayMedia builds a
canvas-captureStream MediaStream + monkey-patches the video track's
getSettings() to report displaySurface: 'monitor'. Production code's
post-grant validation passes. getDisplayMedia returns the synthetic
stream immediately — no picker, no headless flakiness.
A6 prototype result (with Bug B fix in place — current HEAD state):
[PASS] SETUP: badge becomes REC after start
[PASS] A6.1: badge text is '' (NOT 'ERR') after user-stop
[PASS] A6.2: popup is '' (NOT manifest default) after user-stop
[PASS] A6.3: NO recovery notification fired (count delta === 0)
[PASS] A6.4: isRecording=false (via badge proxy)
A6 prototype result (with Bug B fix rewound to `if (false)`):
[PASS] SETUP: badge becomes REC after start
[FAIL] A6.1: badge text is '' (got "ERR")
[FAIL] A6.2: popup is '' (got chrome-extension://.../popup/index.html)
[FAIL] A6.3: notif delta = 0 (got 1)
[PASS] A6.4: isRecording=false ← false-positive (badge='ERR' not 'REC')
The Bug B regression rewind cycle proves the harness CAN catch regression:
4/5 checks turn RED on rewind, 5/5 turn GREEN with the fix restored.
Files in this commit:
- tests/uat/prototype/extension-page-harness.{html,ts} — the harness
page (chrome-extension URL, exposes window.__mokoshHarness.assertA6)
- tests/uat/prototype/a6.test.ts — Puppeteer driver (~270 lines)
- tests/uat/prototype/probe_*.mjs — diagnostic probes used to isolate
the SW dynamic-import blocker (probe_sw.mjs is the key one)
- src/test-hooks/offscreen-hooks.ts — added installFakeDisplayMedia +
dispatchEndedOnTrack + __mokoshOffscreenQuery bridge handler + auto-
install at module load
- vite.test.config.ts — added prototype harness page as rollup input;
added modulePreload.polyfill=false (red herring; harmless)
- src/background/index.ts — removed the broken SW-side gated dynamic
import (this is the BLOCKER unblocker — production 01-11 plan needs
to redesign SW-side test hooks before re-spawning)
Bundle hygiene: prototype runs against dist-test/; production dist/
remains hook-free (Tier-1 grep gate still GREEN, verified via
no-test-hooks-in-prod-bundle.test.ts in the unit test suite).
Vitest baseline: 89/89 GREEN preserved.
Runtime: ~7 seconds end-to-end (launch Chrome + open page + ensure
offscreen + start recording + dispatch ended + settle + assert).
See: research return for VERDICT + recommended next step.
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.