test-driven-development

To start test-driven development, write a failing unit test that defines the desired software behavior before writing any production code. Then, implement the minimal code required to make that test pass, followed by iterative refactoring to clean up the implementation.

The red-green-refactor workflow is a test-first development cycle where you write a failing test, implement just enough production code to make it pass, and then refactor the code iteratively to improve design while ensuring the test continues to pass.

Yes, test-first development is ideal for bug fixes and refactoring because it requires defining expected behavior through automated checks before changing code, preventing regressions across your projects and ensuring software contracts remain intact.

Writing tests before production code drives design-driven testing, which naturally guides API design, error handling, and software contracts by forcing you to define expected behavior and interfaces through automated checks before implementation.

The best way to prevent code regressions during feature development is to enforce expected behavior through unit tests written before production code, ensuring every new feature is guarded by automated checks throughout the development lifecycle.

Writing a failing test first ensures the test actually validates expected software behavior rather than just mirroring existing implementation logic, establishing a robust contract that prevents defects and guides minimal code production.