test-driven-development

Test-driven development prevents regressions by enforcing a test-first design where failing tests define expected behavior before any implementation code is written. This Red-Green-Refactor workflow ensures minimal, meaningful test coverage that guards against future code breakage.

The Red-Green-Refactor workflow is a test-driven development cycle where you first write a failing test (Red), implement just enough code to pass it (Green), and then clean up the implementation without changing behavior (Refactor). This iterative process enforces strict quality guardrails.

Apply TDD during refactoring by writing meaningful failing tests that define the existing expected behavior before altering the code. This ensures the refactor maintains robust software functionality and improves code reliability without introducing unnoticed regressions.

Yes, test-first design applies to both new features and bug fixes. By writing failing tests that define expected behavior before coding, you ensure maintainable, robust software across codebases and prevent future regressions during subsequent modifications.

You should avoid test-driven development when a codebase does not prioritize maintainable, robust software or when strict regression prevention is unnecessary. TDD enforces minimal yet meaningful tests, which may overhead rapid prototyping efforts where immediate code quality is not the primary concern.