Testing

:::info Source Sourced from services/assignment-service/TESTING_STRATEGY.md in the documentation repo. :::

Companion: 16 Testing Strategy & QA

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1. Test Pyramid

                ┌────────────┐
                │   E2E      │  ~30 scenarios, 10%
                ├────────────┤
                │ Contract   │  Event + HTTP, 15%
                ├────────────┤
                │ Integration│  DB + NATS + outbox, 25%
                ├────────────┤
                │    Unit    │  Pure domain, 50%
                └────────────┘

Coverage gate: line 80%, branch 75% — fails CI below threshold.

2. Unit Tests

Scope: domain logic, value objects, RRULE engine, state machines, target resolver, escalation evaluator, reminder planner.

Module	Key cases
RRULEEngine	YEARLY/MONTHLY/WEEKLY frequencies, BYMONTHDAY, BYDAY, EXDATE, TZ (including DST transitions), COUNT cap, UNTIL cap
AssignmentAggregate	all state transitions + invalid transitions; invariant enforcement; draft vs active immutable fields
ComplianceWindowAggregate	state transitions including overdue→completed (late flag), overdue→closed_missed
EscalationEvaluator	steps fire in order; idempotency via (windowId, level)
ReminderPlanner	relative_to_due, on_due, relative_to_overdue; suppression-when-in-progress
TargetResolver	user, org_unit+descendants, dynamic_group; empty set; de-duplication

Framework: Vitest + fast-check for property-based tests on RRULE and state-machine transitions.

3. Integration Tests

Run against real Postgres (Testcontainers) and ephemeral NATS JetStream server.

Scenario	Verifies
Create→activate→materialize	Rows + outbox + schema
Enrollment event → in_progress	Consumer handler + idempotency
Progress completion → completed	Same
Overdue sweeper	Partial-index scan; produces correct events
RLS isolation	Session A cannot read B's tenant
Migration up	All migrations apply cleanly
Partition add for new tenant	Provisioner creates partition + RLS policy

Testcontainers boot under 8 s on CI (cached image).

4. Contract Tests

4.1 Event Schema Contracts

• Every event emitted in a test is validated against @ghasi/event-schemas/assignment/*.v1.json.
• Provider-side Pact: assignment-service publishes for enrollment-service, notification-service, analytics-service. CI fails if we break an event consumer's expectation without a coordinated version bump.

4.2 HTTP OpenAPI Contracts

• dredd / prism runs every OpenAPI example through a live service instance.
• Schema drift CI gate: generated OpenAPI from code ≡ committed spec.

5. E2E Tests

End-to-end through the platform using shared harness (@ghasi/e2e):

Flow	Services involved
Admin creates recurring assignment, learner completes	assignment, tenant, enrollment, progress, notification
Admin creates one-shot assignment, learner misses → closed_missed	assignment, enrollment, progress, notification, analytics
AI suggests assignment, admin accepts, activation succeeds	assignment, ai-gateway, tenant, catalog
Tenant dynamic group changes mid-flight → rebind	tenant, assignment
GDPR erasure for learner with active windows	identity, assignment

E2E uses Playwright for UI flows + direct HTTP for admin and saga inspection.

6. Load / Performance

Tool: k6. Scenarios:

Scenario	Target
Create-activate cycle	100 rps, p95 < 400 ms
List windows (100k rows)	200 rps, p95 < 200 ms
Compliance report 100k windows	p95 < 1.5 s
Materializer stress: 10k users × 100 occurrences	finishes < 60 s, memory < 1 GB
Overdue sweep on 5M windows	completes within 15 min

Ran nightly on staging with synthetic tenant.

7. Chaos / Failure Injection

Using LitmusChaos or Chaos Mesh:

• Kill one pod during materialization — expect resume from cursor, zero duplicate windows.
• Partition NATS — expect outbox to buffer; no data loss on reconnect.
• Force Postgres failover — expect reads degrade, writes retry; SLO breach alert fires.
• Inject 500ms DB latency — p95 budget breach tested; no runaway timeouts.

8. Security Tests

• Semgrep rules for RLS usage (every query must run with tenant context).
• Burp Suite / ZAP against staging every release.
• Fuzzing: RRULE parser fuzzed via go-fuzz-style harness on rrule inputs.
• Tenant-leak red-team test in E2E: forge X-Tenant-Id and expect 403.

9. AI Eval Harness

See AI_INTEGRATION §9:

• 30+ labelled (context, expected proposal) pairs.
• Runs in CI on changes to prompt or client.
• Regression report attached to PR.

10. Offline / Sync Tests

Scripted flows in @ghasi/sync-harness:

• Learner device offline 5 days; windows state changes on server; reconcile on reconnect → exactly the server state wins.
• Admin device edits draft offline; server edits same draft; reconnect → LWW + conflicts list.

11. Mutation Testing

Stryker run weekly on domain package. Mutation score goal: ≥ 70% on packages/domain.

12. Test Data

• Factories in test/fixtures/ producing realistic Assignments and Windows with deterministic ULIDs.
• seed-tenant.ts script provisions a demo tenant with 10k users, 5 assignments, 100k windows for perf dashboards.

13. Branches / PR Gates

Gate	Required
Unit + integration pass	✅
Coverage ≥ 80% line	✅
OpenAPI drift check	✅
Event schema compat check	✅
Security lint (semgrep)	✅
k6 smoke (5 min)	✅
Pact provider verification	✅
E2E happy path	on release-candidate branch

14. Staging Soak

Every release spends 48 h in staging with full synthetic traffic before production.

15. Rollback Verification

Automated: every deploy runs a rollback-preview job that executes the prior image against the new DB schema and confirms compatibility (backward-compat schema only allowed).

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