test-driven-development

Test-driven development is a test-first discipline where you write and validate software behavior through tests before production code. The workflow enforces writing a failing test, authoring minimal code to pass, and refactoring with confidence.

To apply test-driven development for bug fixes, write a failing test that reproduces the specific bug, implement the minimal production code to make it pass, and then refactor safely while keeping the entire test suite green.

Use test-first coding for new features and refactoring when you need early failure visibility and safety against regressions. It ensures you define required behavior before implementation, reducing guesswork across the software lifecycle.

The best way to ensure minimal production code is by following the red-green-refactor workflow: write a failing test for a new capability, implement the simplest code that makes it pass, and refactor only when the suite remains green.

Writing failing tests before production code provides early failure visibility, ensuring you know the required behavior before coding. This reduces guesswork and guards against misaligned implementations and future regressions.