tdd

Test-first development using red-green-refactor involves writing a failing test for one behavior, making it pass, then refactoring the code. This Skill drives that incremental workflow to build features and fix bugs with observable outcomes.

Behavior-driven testing verifies software through public interfaces and observable outcomes rather than internal implementation details. Use it during refactoring to ensure existing behavior remains intact while you improve code structure after the test suite is green.

Write integration tests by targeting the public interface and observable outcomes of the feature. This Skill helps you identify the highest-priority behaviors to test first, ensuring integration-heavy changes are verified one behavior at a time.

Yes, the red-green-refactor workflow applies to bug fixes in existing codebases. You write a test that reproduces the bug as a failing red test, implement the fix to make it green, and then refactor safely with a verified suite.

The best way to plan incremental delivery is to identify the public interface and select the most important behaviors to test first. This Skill helps you choose those high-priority behaviors, reducing risk and rework by making progress one test at a time.

You should not use test-first development when unable to define tests against public interfaces or when changes lack observable outcomes. The workflow requires defining one behavior at a time and refactoring only after the suite is green.