TDD Workflow

Test-driven development implements features by writing a failing test first, then writing minimal code to pass it, and finally refactoring while keeping tests green. This Red-Green-Refactor cycle ensures behavior is validated before implementation and prevents defects.

The Red-Green-Refactor cycle is a TDD workflow: write a failing test (Red), implement minimal code to pass it (Green), then improve the code without breaking tests (Refactor). It enforces test-first discipline, catches defects early, and maintains code quality throughout development.

TDD applies to starting new features, adding functionality, and fixing defects. Writing a failing test before code ensures the expected behavior is clear and prevents regression. It works for any scenario where you want strict test discipline guiding implementation.

Yes. TDD supports iterative improvement of legacy code through test-first changes. By writing failing tests before modifying existing code and refactoring while tests pass, you validate behavior and reduce the risk of introducing new defects.

Test-first development prevents defects by validating expected behavior before code exists and enforcing minimal implementation. Writing tests first ensures requirements are clear and implementation covers only what's needed, reducing gaps and unintended behavior.