| name | test-driven-development |
| description | Write a failing test before changing production behavior. |
Test-Driven Development
Use this skill when adding a feature, fixing a bug, or changing behavior.
Process
- Write one focused test for the new behavior.
- Run it and confirm it fails for the expected reason.
- Implement the smallest change that makes the test pass.
- Run the focused test again.
- Run the full test suite if the change affects shared behavior.
Do not treat a test that only passes after the implementation as proof that the
test would have caught the missing behavior.
