Plan 02-01 Task 1 RED gate. Three failing tests pin D-P2-01
(offscreen-minted Blob URL pipeline) ahead of Plan 02-02 implementation:
1. chrome.downloads.download is called with a blob: URL and NOT a
data:application/zip;base64, URL (closes audit P0-6).
2. A 6 MB archive completes through downloadArchive in under 5 s AND
emits a blob: URL (REQ-archive-export-latency; vi-mocked
remuxSegments short-circuits the muxer for the 6 MB stress path).
3. URL.revokeObjectURL is scheduled with the minted URL after
chrome.downloads.onChanged fires 'complete' (lifecycle hygiene).
RED evidence (vitest 4.1.6 against current HEAD):
× Test 1: chrome.downloads.download was called with
url='data:application/zip;base64,UEsDBAoAAAAAAL1qtFw...'
— D-P2-01 forbids data:application/zip;base64, prefix.
× Test 2: chrome.downloads.download was called with
url='data:application/zip;base64,...' at the 6 MB scale —
D-P2-01 requires blob: prefix.
× Test 3: URL.revokeObjectURL was never called after
chrome.downloads.onChanged 'complete' fired
(chrome.downloads.onChanged._callbacks.length === 0 at probe time).
Implementation notes:
- vitest default env is 'node' (vitest.config.ts); Node 24 ships
URL.createObjectURL + URL.revokeObjectURL + performance as globals,
so no jsdom override is required.
- FileReader is NOT in Node 24; added a minimal FileReader polyfill
(delegates to Blob.arrayBuffer()) so JSZip's Blob ingestion works.
- Test 2 mocks remuxSegments via vi.doMock to bypass muxer monotonic-
timestamp constraints for the synthetic 6 MB payload.
- Tests 1 + 3 drive the SW with the canonical 3-slice raw-3ebml-concat
fixture (same byte offsets as tests/background/webm-remux.test.ts).
- T-02-01-01 mitigation: grep -c '\.skip' returns 0.
Baseline: 155 GREEN preserved (no regressions); this plan adds 3 NEW
RED tests. Plan 02-02 flips them GREEN.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Mark
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