test-driven-development

The test-driven development process requires writing a failing test before any production code, then writing minimal code to pass the test, and finally refactoring. This enforces the Red-Green-Refactor cycle to ensure code quality and reliability.

To fix bugs using the Red-Green-Refactor cycle, first write a failing test that reproduces the bug, then write minimal implementation code to make the test pass, and finally refactor the code while ensuring the test remains green.

You should use test-driven development for unit testing when developing new features, fixing bugs, or refactoring existing code to ensure well-tested, reliable code that strictly meets defined requirements before implementation.

Yes, test-driven development strictly requires writing and verifying a failing test before any production code is written. You must observe the failing test first to ensure the implementation code is driven by test requirements.

Yes, you can use test-driven development for refactoring by guiding the Red-Green-Refactor cycle. The methodology mandates verifying a failing test initially, then cleaning up the code while ensuring the test continues to pass throughout the refactoring process.