testing-fundamentals

A structured testing strategy uses the testing pyramid to define proportions for unit, integration, and E2E tests. This approach guides you on when to apply each test type, replacing guesswork with a clear testing scope across your frontend and backend stacks.

To write maintainable unit tests using Vitest or Jest, apply the Arrange-Act-Assert (AAA) pattern. This structures tests into setup, execution, and verification phases, ensuring readable test logic for pure functions and module boundaries.

The best way to start implementing E2E tests with Playwright is to create a test for a critical user flow like login. This establishes an end-to-end testing scope that validates the entire stack, complementing your lower-level unit and integration tests.

You should use integration testing instead of unit testing when validating module boundaries. While unit tests cover pure functions, integration tests ensure different parts of your frontend and backend stacks interact correctly, forming the middle layer of the testing pyramid.

Yes, this testing approach works for both frontend and backend stacks. The strategy maps testing patterns to frameworks like Vitest, Jest, and Playwright, establishing recommended coverage and test scopes applicable across modern full-stack environments.