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, bugfix, and refactor is backed by a test that was watched failing before implementation. ## Core Features & Use Cases - Red-Green-Refactor Enforcement: Guides the AI through writing a failing test, verifying the failure, writing minimal passing code, and refactoring while keeping tests green. - Rationalization Detection: Lists common excuses for skipping TDD (e.g., "too simple to test", "I'll test after") and mandates deleting code written before tests. - Testing Anti-Pattern Reference: Ships a companion reference covering mock-behavior testing, test-only production methods, incomplete mocks, and over-mocking, with gate functions to catch violations. - Use Case: When asked to fix a bug where an empty email is accepted, the Skill directs writing a failing test asserting the rejection error, verifying it fails, then implementing the minimal validation fix. ## Quick Start Ask the AI to implement a new feature or bugfix using test-driven development with a failing test written and verified before any production code.
