Wire A24 into the Plan 01-13 Approach B UAT harness as the binding empirical
gate for D-P2-01. A24 verifies end-to-end that SAVE_ARCHIVE → chrome.downloads.
download receives a `blob:` URL prefix (NOT `data:application/zip;base64,`),
closing audit P0-6 functionally. The Plan 02-02 unit tests pin the wire-format
at the SW↔offscreen boundary; A24 pins it at the chrome.downloads platform
boundary through a real Chrome instance.
Strategy: chrome.downloads.onCreated listener captures the URL cross-realm.
The plan's <action> block proposed a chrome.downloads.download monkey-patch
installed in the harness page realm — but that intercepts only same-realm
calls, missing the SW's call. The canonical cross-realm capture pattern is
chrome.downloads.onCreated (fires for any download initiated by any extension
realm, with the full DownloadItem including .url). Documented as a deviation
from the plan's pseudo-code in SUMMARY.md (Rule 1 — bug fix vs the pseudo-code
strategy; same A24 contract verified, correct mechanism).
Files modified:
- tests/uat/extension-page-harness.ts (+~150 lines): assertA24 + A24_* constants
- tests/uat/lib/harness-page-driver.ts (+~30 lines): driveA24 page.evaluate wrapper
- tests/uat/harness.test.ts (+~10 lines): import driveA24, append to drivers list
Verification:
- HEADLESS=1 npm run test:uat → 25/25 GREEN (24 baseline + A24)
- capturedUrl observed: blob:chrome-extension://lpgnfoop.../...
- npx vitest run → 171/171 GREEN (no regression)
- Tier-1 FORBIDDEN_HOOK_STRINGS gate → 13/13 GREEN (12 strings preserved)
- npx tsc --noEmit → clean
Plan 02-04 scope: 1/3 tasks landed (A24); Tasks 2-3 add A25+A26+A27+A28
(latency, meta.json shape, multi-tab strict, REQ-archive-layout strict).
Mark
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