routing-engine — Testing Strategy

Status: populated | Last updated: 2026-04-18

1. Coverage Target

Minimum 80% line coverage enforced in CI.

2. Test Pyramid

2.1 Unit Tests

Framework: Jest + ts-jest

What to unit-test:

• RoutingStrategyService: test COST, PRIORITY, FAILOVER strategy selection with mock candidate lists.
• PrefixMatchingService: longest-prefix match algorithm with edge cases (exact match, no match, overlapping prefixes).
• CacheKeyBuilder: key generation for all combinations of prefix/accountId/messageType.
• HealthEventHandler: Redis write logic, cache invalidation logic, NAK on Redis failure.
• Input validation logic for SelectOperatorRequest.

Key test cases:

describe('RoutingStrategyService', () => {
  it('COST strategy selects operator with lowest cost', () => {});
  it('PRIORITY strategy selects operator with lowest priority number', () => {});
  it('FAILOVER strategy skips UNBOUND operators and picks first BOUND', () => {});
  it('returns null when all candidates are UNBOUND', () => {});
});

describe('PrefixMatchingService', () => {
  it('matches longest prefix for +447911123456', () => {});
  it('returns null when no prefix matches', () => {});
  it('prefers +4479 over +447 for +44791*', () => {});
});

2.2 Integration Tests

Framework: Jest + testcontainers (PostgreSQL, Redis) Scope: Full SelectOperator handler with real DB and Redis containers.

What to integration-test:

• Full routing resolution from DB seed → cache write → cached response on second call.
• Cache invalidation when operator.health UNBOUND event is processed.
• /ready endpoint returns 503 when Redis or PostgreSQL is unavailable.
• NATS health event consumer correctly updates Redis state.

Test data:

• Seed scripts in test/fixtures/ops_routing.sql.
• Cover: UK prefix (+44), Afghanistan prefix (+93/+9375), no-rule prefix.

2.3 Contract Tests (Consumer-Driven)

Framework: Pact (protobuf provider tests) Scope: Verify that routing-engine satisfies the proto contract that sms-orchestrator depends on.

• sms-orchestrator publishes a Pact consumer contract for SelectOperator.
• routing-engine CI pipeline runs the provider verification step.
• Pact Broker is deployed in the cluster CI environment.

2.4 Performance / Latency Tests

Framework: ghz (gRPC load testing tool) in CI smoke environment.

Acceptance criteria:

• 500 req/s sustained for 30 s → P95 latency ≤ 50 ms, 0 error responses.
• Run against a pre-seeded environment with 50 routing rules and 10 operators.

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3. CI Pipeline Gates

Stage	Tool	Pass criteria
Unit tests	Jest	All pass; ≥ 80% coverage
Integration tests	Jest + Testcontainers	All pass
Contract verification	Pact	Provider verification passes
Lint	ESLint	0 errors
Type check	tsc --noEmit	0 errors
Performance smoke	ghz	P95 ≤ 50 ms at 500 RPS