Architectural pivot triggered by feasibility research prototype
(commit c647f61, A6 PASS 5/5 + Bug-B regression rewind verified).
Two empirical findings invalidate original architecture:
1. MV3 service workers BLOCK dynamic import. await import('test-hooks/
sw-hooks') in src/background/index.ts silently kills the SW —
chunk loads, await never resolves, no listeners register. Cited
Chromium es_modules.md + w3c/webextensions#212.
2. Puppeteer WebWorker.evaluate against MV3 SW only exposes chrome.
{loadTimes,csi} — not the extension chrome.* API surface.
The Wave 1 (cb1a729) SW-side hooks are fundamentally broken in test
builds (production unaffected — gated by __MOKOSH_UAT__ which is
false in prod). Executor must DELETE the SW-side dynamic import +
sw-hooks.ts entirely; offscreen-side hooks stay (offscreen IS a DOM
document; dynamic import works there).
Replacement (Verdict-A architecture, proven by prototype):
- Extension-internal harness page at chrome-extension://<id>/tests/
uat/extension-page-harness.html — privileged extension context
with FULL chrome.* API access
- Puppeteer drives the page via page.goto + page.evaluate
- For SW state: page calls chrome.runtime.sendMessage; SW responds
via production messaging
- For getDisplayMedia: offscreen-side installFakeDisplayMedia() patches
navigator.mediaDevices.getDisplayMedia → Canvas captureStream
synthetic MediaStream
A6 (Bug B regression catch) PROVEN. Industry-standard pattern (MetaMask,
eyeo, Chrome MV3 official testing docs all converge).
Effort remaining: ~7-10h subagent budget (Wave 0 + bonus debug-import
commits keep; Wave 1 hooks rewire 30min; Wave 2 scaffolding 1-2h;
Wave 3 13 more assertions 4-6h; Wave 4 closure 1h).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Mark
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