testing-strategies

To build a testing pyramid, you balance fast unit tests at the base, fewer integration tests in the middle, and rare E2E tests at the top. This structure ensures quick feedback while validating critical user workflows like API endpoints and browser interactions.

The AAA structure in unit testing organizes tests into Arrange, Act, and Assert phases. It provides a deterministic, isolated pattern to validate logic, often using Given-When-Then formats and mocking to verify outcomes without external dependencies.

You apply TDD cycles by following the RED-GREEN-REFACTOR iteration. Write a failing test first, implement the minimum code to pass the test, then refactor the code safely while maintaining test coverage and ensuring no regressions.

The best way to test API endpoints and user flows is through integration and E2E tests. Write API-focused integration tests for endpoint validation and use tools like Playwright for browser-based E2E tests to cover full critical workflows.

Use mocking in integration tests when you need deterministic, isolated validation of logic without triggering real external dependencies. Mocking helps stabilize tests by simulating API responses and database interactions, ensuring consistent feedback.

Yes, this testing strategy works without existing coverage by planning a test pyramid from scratch. It helps you define clear unit, integration, and E2E goals, establishing reliable test patterns for new projects immediately.