test-driven-development

Test-driven development workflows prevent untested production code by mandating a strict red-green-refactor cycle. This approach requires writing a failing test first, implementing minimal code to pass, and refactoring to eliminate unverified edge cases and technical debt.

Common testing anti-patterns include writing tests after implementation, testing mock behavior instead of real outcomes, and adding test-only methods to production code. Test-driven development prevents these by requiring tests to fail before any implementation code is written.

Apply the red-green-refactor cycle for bug fixes and refactoring by first writing a test that reproduces the bug or verifies the desired behavior change, confirming it fails, then writing the minimal production code to make it pass before cleaning up the code.

Yes, test-first development works for new feature implementation, bug fixes, refactoring, and behavior changes. It applies the red-green-refactor cycle to all software engineering tasks, ensuring every code change is fully verified before deployment.

Writing tests after implementation increases technical debt because it rationalizes skipping tests and allows untested edge cases to reach production. Test-first workflows eliminate this risk by verifying that each test fails before writing the minimal implementation code.