test-driven-development

The RED-GREEN-REFACTOR cycle in test-driven development requires writing a failing test, implementing minimal code to pass it, and then refactoring. This enforces non-negotiable checkpoints to ensure no production code exists without a verified requirement.

To implement a new feature using test-driven development, you first write a failing test that defines the feature's expected behavior. Next, you write just enough code to make the test pass, and finally, you refactor the implementation while ensuring all tests still pass.

Yes, test-driven development is applicable to all software development phases including bug fixing and code refactoring. It guides developers to write failing tests that reproduce bugs before implementation, creating a robust safety net for future changes.

Test-driven development works seamlessly with agile workflows by enforcing strict quality gates and continuous testing. It ensures high-quality code and reduces bugs by requiring verified tests before any production code is written during iterative development cycles.

Writing failing tests before production code ensures that the test actually validates the requirement and prevents untested code from entering the codebase. This hard gate mechanism reduces bugs and creates a robust safety net for future refactoring.