backend-unit-integration-e2e-testing

Structure backend tests by maintaining clear separation of concerns across unit, integration, and E2E layers with explicit roles and tooling guidance. This approach reduces flaky tests and misaligned coverage by defining explicit mocking boundaries and deterministic test data.

The best way to manage tests in CI is providing separate test scripts like test:unit, test:integration, and test:e2e. This separation ensures clear CI readiness and allows targeted execution of unit, integration, and E2E tests locally or in pipelines.

Playwright works for both backend API testing and browser-based E2E tests. The skill provides Playwright APIs to handle typical scenarios including HTTP endpoints, database interactions, and UI or API workflows across multiple test environments.

Testcontainers can be used for database integration testing in Java and JavaScript backends. The skill provides stack-agnostic guidance with examples for Java and JavaScript/TypeScript backends, utilizing Testcontainers alongside Spring Boot Test and REST Assured.

Define mocking boundaries for backend integration tests by ensuring clear separation of concerns between unit, integration, and E2E layers. Use deterministic test data and explicit tooling guidance like JUnit and Mockito to isolate HTTP endpoints and database interactions.