Adds 23 tests across 4 files, taking total broker coverage from
21 → 44 passing in ~2.5s.
Unit tests (no I/O):
- tests/rate-limit.test.ts (6): TokenBucket capacity, refill rate,
no-overflow cap, independent buckets per key, sweep GC.
- tests/metrics.test.ts (5): all 10 series present in /metrics,
counter increment semantics, labelled series produce distinct lines,
gauge set overwrites, Prometheus format well-formed.
- tests/logging.test.ts (5): JSON per line, required fields (ts, level,
component, msg), context merging, level preservation, no plain-text
escape hatches.
Integration tests (spawn real broker subprocesses on random ports):
- tests/integration/health.test.ts (7):
* GET /health 200 + {status, db, version, gitSha, uptime} (healthy DB)
* GET /health 503 + {status:degraded, db:down} (unreachable DB)
* GET /metrics 200 text/plain with all expected series
* GET /nope → 404
* POST /hook/set-status oversized body → 413
* POST /hook/set-status 6th req/min → 429
* Rate limit isolation by (pid, cwd) key
Integration tests use node:child_process (vitest runs under Node, not
Bun — Bun.spawn isn't available). Each suite spawns its own broker
subprocess with a random port + tailored env vars.
Not yet covered (flagged for follow-up):
- WebSocket connection caps (needs seeded mesh + WS client setup)
- WebSocket message-size rejection (ws.maxPayload behavior)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
