test-driven-development

Test-driven development is a disciplined approach where you write tests before implementation, ensuring code behaves as intended from the start and reducing regressions. It uses early failure visibility to detect broken behavior immediately before coding.

To apply the red-green-refactor cycle, write a failing test for the target behavior, implement the minimal production code required to pass that test, then refactor the code for clarity without changing its behavior.

You should use TDD when you need guardrails for design to discourage over-engineering and encourage small, testable units. It provides a structured workflow where failures drive minimal, testable production code.

Test-driven development works by writing a failing test for the target behavior and implementing minimal code to pass it. This disciplined approach reduces regressions and ensures intended behavior across both new features and existing team workflows.

Writing tests first improves quality by ensuring broken behavior is detected immediately before coding begins. This approach discourages over-engineering and encourages small, testable units, driving minimal production code and reducing regressions.