test-driven-development

Test-driven development is a workflow that validates software behavior by writing failing tests before production code. It enforces a red-green-refactor cycle to catch design issues early and reduce regression risk.

To start unit testing with a test-first workflow, write a failing test that defines the desired feature, then implement minimal production code to pass the test, and finally refactor the code for clarity.

Use test-first development during refactoring to maintain code quality and prevent regressions. Writing tests before changing existing behavior ensures your refactoring preserves intended functionality and catches failures immediately.

Yes, test-driven development works for bug fixes and feature development. You apply the red-green-refactor cycle to write a failing test that reproduces the bug or defines the feature, then implement code to pass it.

Red-green-refactor drives design by requiring a failing test first, whereas testing after coding only validates existing implementation. The test-first approach provides living documentation and ensures code is written to pass specific expectations.