Testing

The API has three levels of testing, each with its own Jest configuration. As a general rule, unit tests should cover business logic and handler behaviour, integration tests should cover infrastructure code against real dependencies, and E2E tests should cover complete HTTP request flows through the application.

Unit tests

Tests for domain logic and application layer handlers. All dependencies are mocked — no database or Redis required.

npm run test:unit

Configuration: jest.config.js — scans test/unit/**/*.test.ts.

Integration tests

Tests for infrastructure adapters (repositories, controllers) against real databases. Requires the test Docker Compose services to be running.

docker compose up -d
npm run test:integration

Configuration: jest-integration.config.js.

Test containers run on separate ports so they don't conflict with the dev database:

• PostgreSQL test: port 5433
• Redis test: port 6380

E2E tests

Full end-to-end tests that boot the NestJS application and make HTTP requests against it.

docker compose up -d
npm run test:e2e

Configuration: jest-e2e.config.js.

Test patterns

Unit test example — command handler:

test/unit/auth/application/command/create-token.handler.test.ts

Mocks the token repository and domain service. Asserts the command handler produces the expected events.

Integration test example — repository:

test/integration/auth/infrastructure/persistence/token.repository.test.ts

Runs against the test Postgres container. Exercises the Prisma adapter directly.