fix(bridge-redis): close subscribe-readiness race that could drop a live message#5
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…ive message subscribe() started its XREAD loop at '$' and returned without awaiting the first (blocking) read. '$' only resolves to the stream's last id when that read registers server-side, so a post() (XADD) racing in during the startup window got an id below the resolved '$' and was dropped forever — it never reached the subscriber. Surfaced as an intermittent failure of the "identical backendMsgId + cursor via live push and via catch-up" conformance test under CI load (Node 24). Fix: capture a concrete stream tail id via XINFO STREAM, awaited before subscribe() resolves, and read strictly after it. A concrete id has no gap, so a message added during startup is still delivered. Falls back to '0' when the stream doesn't exist yet (no history to skip). Verified: redis conformance 20/20. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Fixes the intermittent Redis conformance failure seen on
main(run) — and it was a real bug, not just a slow test.Root cause
bridge-redissubscribe()started itsXREADloop at'$'and returned without awaiting the first (blocking) read (void loop()).'$'only resolves to the stream's last id when that read actually registers server-side. Apost()(XADD) racing in during that startup window gets an id below the resolved'$'and is dropped forever — so the subscriber receives 0 messages (hence the 3svi.waitFortimeout, not a late arrival). Rare; it slipped through under Node 24 CI load.Fix
Capture a concrete stream tail id via
XINFO STREAM, awaited beforesubscribe()resolves, and read strictly after it. A concrete id has no gap —XREADreturns everything after it, including messages added during startup. Falls back to'0'when the stream doesn't exist yet (no history to skip). Only touchespackages/bridge-redis.Verification
redisconformance suite: 20/20 consecutive runs green (was intermittently failing the live-push test).npm test: 26 files passed / 5 skipped, Redis running for real.tsc -bclean.Note
fix:title → this cuts a 0.2.1 patch release on merge, republishing the correctedbridge-redis(with provenance), and returnsmainto green.🤖 Generated with Claude Code