test-driven-development

What problem does it solve? Developers often write production code first and add tests afterward, which produces tests that pass immediately and prove nothing about correctness. This Skill enforces a strict test-first discipline so every feature and bugfix is backed by a test that was watched failing before implementation. ## Core Features & Use Cases - Red-Green-Refactor Enforcement: Guides the full cycle of writing a failing test, verifying the failure, writing minimal passing code, and refactoring while staying green. - Rationalization Detection: Lists common excuses for skipping TDD (such as "too simple to test" or "I'll test after") and explains why each one fails. - Testing Anti-Pattern Reference: Ships a companion reference covering mock-behavior testing, test-only production methods, incomplete mocks, and over-mocking. - Use Case: When fixing a bug where an empty email is accepted, write a failing test asserting the rejection, watch it fail, implement the minimal validation, and confirm all tests pass before refactoring. ## Quick Start Ask the AI to implement a new feature or bugfix using strict test-driven development with a failing test written first.