cim_summary/.planning/phases/02-backend-services/02-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
02-backend-services	01	analytics	supabase vitest fire-and-forget analytics postgresql migrations	phase provides 01-data-foundation/01-01 getSupabaseServiceClient per-method call pattern, migration file format phase provides 01-data-foundation/01-02 makeSupabaseChain() Vitest mock pattern, vi.mock hoisting rules	Migration 013 document_processing_events table DDL with indexes and RLS analyticsService.recordProcessingEvent() fire-and-forget void write to Supabase analyticsService.deleteProcessingEventsOlderThan() retention delete returning row count Unit tests for both exports (6 tests)	02-backend-services/02-02 (monitoring services) 02-backend-services/02-03 (health probe scheduler) 03-api (callers that instrument processing pipeline events)	added patterns Fire-and-forget analytics: void return type (not Promise<void>) prevents accidental await on critical path void supabase.from(...).insert(...).then(callback) pattern for non-blocking writes with error logging getSupabaseServiceClient() called per-method inside each exported function, never cached at module level	created modified backend/src/models/migrations/013_create_processing_events_table.sql backend/src/services/analyticsService.ts backend/src/__tests__/unit/analyticsService.test.ts	recordProcessingEvent return type is void (not Promise<void>) — prevents callers from accidentally awaiting analytics writes on the critical processing path Optional fields (duration_ms, error_message, stage) coalesce to null in insert payload — consistent nullability in DB created_at set explicitly in insert payload (not relying on DB DEFAULT) so it matches the event occurrence time	Analytics void function test: expect(result).toBeUndefined() + expect(typeof result).toBe('undefined') — toHaveProperty throws on undefined, use typeof check instead Fire-and-forget error path test: mock .insert().then() directly to control the resolved value, flush microtask queue with await Promise.resolve() before asserting logger call	ANLY-01 ANLY-03	3min	2026-02-24

Phase 02 Plan 01: Analytics Service Summary

Fire-and-forget analyticsService with document_processing_events migration — void recordProcessingEvent that logs errors without throwing, and deleteProcessingEventsOlderThan returning row count

Performance

• Duration: 3 min
• Started: 2026-02-24T19:21:16Z
• Completed: 2026-02-24T19:24:17Z
• Tasks: 2
• Files modified: 3

Accomplishments

• Migration 013 creates document_processing_events table with event_type CHECK constraint, indexes on created_at and document_id, and RLS enabled — follows migration 012 pattern exactly
• recordProcessingEvent() has void return type (not Promise<void>) and uses void supabase.from(...).insert(...).then(callback) to ensure errors are logged but never thrown, never blocking the processing pipeline
• deleteProcessingEventsOlderThan() computes cutoff via Date.now() - days * 86400000, deletes with .lt('created_at', cutoff), returns data.length as row count
• 6 unit tests covering all exports: insert payload, void return type, error swallowing + logging, null coalescing for optional fields, cutoff date math, and row count return

Task Commits

Each task was committed atomically:

1. Task 1: Create analytics migration and analyticsService - ef88541 (feat)
2. Task 2: Create analyticsService unit tests - cf30811 (test)

Plan metadata: (docs commit to follow)

Files Created/Modified

• backend/src/models/migrations/013_create_processing_events_table.sql - document_processing_events DDL with UUID PK, CHECK constraint on event_type, indexes on created_at + document_id, RLS enabled
• backend/src/services/analyticsService.ts - recordProcessingEvent (void, fire-and-forget) and deleteProcessingEventsOlderThan (Promise)
• backend/src/__tests__/unit/analyticsService.test.ts - 6 unit tests using established makeSupabaseChain() pattern

Decisions Made

• recordProcessingEvent return type is void (not Promise<void>) — the type system itself prevents accidental await, matching the architecture decision in STATE.md ("Analytics writes are always fire-and-forget")
• Optional fields coalesce to null in the insert payload rather than omitting them — keeps the DB row shape consistent and predictable
• created_at is set explicitly in the insert payload (not via DB DEFAULT) to accurately reflect event occurrence time rather than DB write time

Deviations from Plan

Auto-fixed Issues

1. [Rule 1 - Bug] Fixed toHaveProperty assertion on undefined return value

• Found during: Task 2 (first test run)
• Issue: expect(result).not.toHaveProperty('then') throws TypeError: Cannot convert undefined or null to object when result is undefined — Vitest's toHaveProperty cannot introspect undefined
• Fix: Replaced with expect(typeof result).toBe('undefined') which correctly verifies the return is not a thenable without requiring the value to be an object
• Files modified: backend/src/__tests__/unit/analyticsService.test.ts
• Verification: All 6 tests pass after fix
• Committed in: cf30811 (Task 2 commit)

---

Total deviations: 1 auto-fixed (Rule 1 — runtime error in test assertion) Impact on plan: Fix required for tests to run. The replacement assertion is semantically equivalent and more idiomatic for checking void returns.

Issues Encountered

• Vitest toHaveProperty throws on undefined/null values rather than returning false — use typeof result checks when verifying void returns instead.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• analyticsService is ready for callers — import recordProcessingEvent from '../services/analyticsService' and call it without await at instrumentation points
• Migration 013 SQL ready to run against Supabase (requires manual psql or Dashboard execution)
• makeSupabaseChain() pattern from Phase 1 confirmed working for service-layer tests (not just model-layer tests)
• Ready for Phase 2 plan 02: monitoring services that will call recordProcessingEvent during health probe lifecycle

---

Phase: 02-backend-services Completed: 2026-02-24

Self-Check: PASSED

• FOUND: backend/src/models/migrations/013_create_processing_events_table.sql
• FOUND: backend/src/services/analyticsService.ts
• FOUND: backend/src/tests/unit/analyticsService.test.ts
• FOUND: .planning/phases/02-backend-services/02-01-SUMMARY.md
• FOUND commit ef88541 (Task 1: analytics migration + service)
• FOUND commit cf30811 (Task 2: unit tests)