---
name: Processor Service
description: processor service scaffold, conventions, and known test patterns learned during Phase 1 tasks 1.1–1.4
type: project
---

Phase 1 tasks 1.1–1.4 landed. Key facts for tasks 1.5–1.11:

**Architecture divergence from tcp-ingestion:**
- ESLint `import/no-restricted-paths` zone: `src/core/` cannot import `src/domain/` (not `src/adapters/` like tcp-ingestion). `src/domain/` is preemptive for Phase 2.
- `INSTANCE_ID` defaults to `'processor-1'` (fixed string), not a random UUID prefix. Rationale: deterministic names are better for container environments.
- `REDIS_CONSUMER_NAME` defaults to `INSTANCE_ID` at runtime (after schema parse), not as a zod schema default — because it depends on `INSTANCE_ID` value.

**Test patterns:**
- `connectWithRetry` tests: use `maxAttempts=1` for the "calls process.exit(1)" case to avoid fake-timer unhandled rejection noise. The noise occurs when a backoff `setTimeout` resolves after the outer promise has already thrown via process.exit mock.
- Migration runner tests: `isMigrationApplied` calls `pool.query` (pool-level, not through client). Handlers on client mock do NOT affect EXISTS checks.
- `vi.mock('node:fs/promises')` pattern used in migrate.test.ts to isolate filesystem reads.

**Why:**
Phase 1 throughput pipeline. Tasks 1.5–1.8 add consumer/writer/state on top of this foundation.

**How to apply:**
When implementing 1.5 (Redis consumer), 1.6 (device state), 1.7 (position writer), 1.8 (main wiring) — all imports must use `.js` extension, no path aliases, strict ESM. The `connectWithRetry` pattern from pool.ts should be mirrored for ioredis in consumer.ts.