testing

Integration tests are end-to-end flows exercising the actual application stack, while unit tests cover complex logic like state machines and validation rules. The guidance favors integration tests for broad coverage and reserves unit tests for calculations, validation, and parsing logic.

Implement TDD by drafting a failing test for a key requirement, then building the feature until the test passes. Run the full suite until all tests pass to ensure code reliability. This quality-first rule applies all applicable test types if a component spans multiple categories.

Choose UI testing strategies by classifying components as Presentational, Smart/Container, or Form-heavy. Apply matching test strategies for each type, and if a component spans multiple categories, apply all applicable test types to ensure comprehensive coverage of business rules.

Yes, you can use Playwright for interactive development and Playwright Test for CI regression. The guidance standardizes browser testing tools by utilizing Playwright to drive interactive development workflows and Playwright Test to automate regression checks in continuous integration pipelines.

Avoid brittle tests by encoding requirements instead of implementation details, ensuring tests validate essential business rules rather than internal mechanics. Good assertions focus on behavioral outcomes and application flows, preventing test failures from minor code refactoring.