What problem does it solve? Code written before tests often ships with unverified behavior, hidden bugs, and tests that pass immediately without proving anything. This Skill enforces a strict test-first discipline so every line of production code is backed by a test that was watched failing first. ## 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. - Anti-Rationalization Guardrails: Provides explicit rebuttals to common excuses like "I'll test after" or "deleting code is wasteful", with red flags that trigger starting over. - 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 fixing a bug where empty emails are accepted, write a failing test asserting the rejection, watch it fail, implement the minimal validation, verify green, and refactor—ensuring the fix is proven and regression-protected. ## Quick Start Use the test-driven-development skill to implement this feature by writing a failing test first, then the minimal code to make it pass.
