test-driven-development

What problem does it solve? Code written before tests often ships untested or with tests that pass immediately and prove nothing. This Skill enforces strict test-driven development so every feature and bugfix starts with a failing test that verifies the intended behavior. ## Core Features & Use Cases - Red-Green-Refactor Cycle: Guides writing one failing test, verifying it fails for the right reason, implementing minimal code, and refactoring while staying green. - Rationalization Detection: Lists common excuses for skipping TDD ("too simple to test", "I'll test after") with concrete rebuttals and red flags that trigger a restart. - Test Quality Rules: A companion reference defines how to write honest tests — naming the break each test catches, asserting real behavior instead of mocks, and running a mutation check. - Use Case: When fixing a bug where empty emails are accepted, write a failing test asserting the rejection, watch it fail, implement the validation, and confirm the suite passes. ## Quick Start Ask the agent to implement the next feature or bugfix using strict test-driven development with a failing test written first.