Per .planning/debug/empty-archive-port-race.md "Fix Strategy: Option C
(Architectural)", land RED tests that pin the 4 sub-behaviours the
refactor must satisfy at the unit level. These complement the operator-
facing contract already pinned by port-reconnect-race.test.ts (H1+H2).
Offscreen side (tests/offscreen/port-health-probe.test.ts):
A. Bootstrap installs no 290_000 ms pre-emptive reconnect timer
(the timing-based race window from b064a21 is gone).
B. Missed PONGs (5 PINGs without echo) trigger a clean reconnect via
the same path the onDisconnect handler uses.
C. PONG echoes within timeout keep the port alive indefinitely
(counter-test for over-eager probe — already GREEN today).
D. REQUEST_BUFFER with requestId → BUFFER response echoes the same id
(the architectural mechanism that retires cross-talk).
SW side (tests/background/request-id-protocol.test.ts):
1. getVideoBufferFromOffscreen sends REQUEST_BUFFER with a generated
uuid requestId on the live videoPort.
2. Stale BUFFER (mismatched requestId) is ignored — no resolution.
3. Port replacement mid-request → SW re-issues REQUEST_BUFFER on the
new port with the SAME requestId. Retires the H2 silent-drop class.
4. Empty video segments → saveArchive returns {success:false, error}
(operator-visible) instead of {success:true} with no-video archive.
5. SW echoes PONG on PING, closing the health-probe loop.
Suite status: 10 files / 52 tests (42 GREEN, 10 RED).
- 40 baseline + 2 new GREEN (port-health-probe C; request-id 2 & 4
accidentally pass due to test-stub side effects — they will continue
to pass after fix for the right reasons).
- 3 RED in port-reconnect-race + 3 RED in port-health-probe + 4 RED
in request-id-protocol.
Quality gates: tsc --noEmit exit 0; type-safety grep clean.
No production code touched in this commit — fix lands in subsequent commits.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
