Frontend Testing Strategies

A well-tested frontend catches regressions early, documents expected behaviour, and gives developers confidence when refactoring. The testing pyramid guides how much effort to invest at each level: many unit tests, fewer integration tests, and a small number of end-to-end tests.

Unit Tests

Unit tests cover individual functions or components in isolation. Keep them fast and deterministic. Tools like Vitest and Jest excel here. Mock external dependencies so tests focus on the unit's logic alone.

Integration Tests

Integration tests verify that several units work correctly together. In a React app, this might mean rendering a component tree that makes a real (or mocked) API call and asserting on the final DOM output. Testing Library is the standard choice.

End-to-End Tests

E2E tests drive a real browser through user journeys. Playwright is the recommended tool — it supports all major browsers, has a powerful locator API, and runs tests in parallel with trace recording for debugging failures.