What problem does it solve? Writing code before tests leads to unverified implementations, biased tests written after the fact, and bugs discovered only in production. This Skill enforces a strict test-first discipline so every behavior change is proven by a failing test before any production code exists. ## Core Features & Use Cases - Red-Green-Refactor Enforcement: Guides the full TDD cycle—write a failing test, verify it fails for the right reason, write minimal code to pass, then refactor while staying green. - Rationalization Detection: Lists common excuses ("I'll test after", "too simple to test") with counterarguments, plus red flags that signal you should delete code and start over. - Testing Anti-Pattern Reference: Covers testing mock behavior, test-only methods in production classes, incomplete mocks, and mocking without understanding dependencies. - Use Case: When fixing a bug like an empty email being accepted, write a failing test reproducing it, watch it fail, implement the minimal validation fix, and confirm all tests pass. ## Quick Start Ask the AI to implement a new feature or bugfix using strict test-driven development with a failing test written first.
