test-driven-development

Test-driven development is a test-first approach where you write a failing test before any production code. It enforces a disciplined red-green-refactor workflow to validate behavior, implement minimal code, and refactor safely across common development scenarios.

The red-green-refactor cycle in unit testing involves writing a failing test first, implementing the minimal code to pass that test, and then safely refactoring the implementation. This cycle repeats continuously to ensure high-quality software.

Yes, test-driven development applies during bug fixes and refactors. You write a failing test that captures the expected behavior, implement the minimal code to fix the issue, and then refactor safely while ensuring all tests pass.

The best way to enforce TDD discipline is by following a guided workflow that prompts writing a failing test before implementation. This approach reinforces meaningful test naming and avoids premature optimization during the red-green-refactor cycle.

You should avoid a test-first approach when the expected behavior is completely undefined or for throwaway prototypes. The red-green-refactor workflow requires well-named tests and explicit coverage, making it best suited for feature work, bug fixes, and refactoring.