test-driven-development

Test-driven development requires writing a failing unit test first, then creating minimal implementation code to pass it, and finally refactoring while keeping tests green. This enforces reliable behavior validation before production code exists.

The red-green-refactor workflow is a test-first cycle where you write a failing test (red), implement the minimal solution to pass it (green), and safely refactor the code while maintaining passing tests to ensure regression prevention.

To avoid common testing mistakes with mocks in TDD, ensure you do not test the mocks themselves, avoid adding test-only production methods, and prevent creating incomplete mocks by following strict mock usage guidelines during test validation.

Yes, test-first workflows apply to bug fixes and refactoring by requiring a failing test that reproduces the bug or validates behavior changes before modifying production code, ensuring reliable automated testing and regression prevention throughout the process.

Yes, you need an environment that supports reliable automated testing to follow TDD practices. The workflow requires executing unit tests repeatedly to validate the red-green-refactor cycle and ensure code quality during behavior changes.