test-driven-development

Test-driven development starts by writing a failing test for the intended behavior, then implementing minimal production code to pass that test. This enforces a test-first discipline that verifies alignment with requirements and reduces later debugging time.

The Red-Green-Refactor cycle is a test-driven development practice where you iterate on failing tests, write minimal code to pass them, and then refactor with confidence. It drives reliable software design by ensuring continuous automated verification.

Yes, test-first development applies to bug fixes, refactors, and behavior changes where regressions must be avoided. It mandates writing failing tests before production code to document expected behavior and ensure verifiable automated checks.

Writing a mandatory failing test before production code prevents regressions and documents expected behavior. It forces a test-first approach that resolves the risk of implementing the wrong behavior and guides minimal, accurate code changes.

Test-driven development is the best way to avoid regressions during behavior changes. By enforcing a Red-Green-Refactor cycle and mandatory failing tests, it provides clear discipline and verifiable automated checks for reliable software design.