tdd-workflow

Test-driven development begins by defining user journeys and generating comprehensive edge, error, and boundary test cases. You run these tests expecting initial failure, then implement minimal code changes to pass, and finally verify 80%+ coverage and test independence.

To maintain 80% test coverage during refactoring, enforce explicit branch, function, and line coverage thresholds across unit, integration, and end-to-end layers. Validate critical user flows with Playwright and ensure all tests remain independent.

Integration testing validates API endpoints, database interactions, and external calls, whereas Playwright E2E tests validate critical user journeys and broader application flows. Both layers are required to meet the 80% coverage threshold.

Yes, you can use Jest and Playwright together. Jest handles unit and integration testing for API endpoints and database interactions, while Playwright validates critical user journeys and end-to-end flows to ensure comprehensive coverage.

A strict TDD workflow enforcing 80% coverage and failing tests before implementation may not suit rapid prototyping or experimental spikes where immediate functionality matters more than comprehensive edge, error, and boundary test validation.

Writing tests before implementing code prevents regressions and hidden bugs. This test-driven approach turns feature changes, bug fixes, and refactoring into a sequence starting from user-focused test cases, ensuring minimal code changes and reliable coverage.