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 Cycle: Guides writing one minimal failing test, verifying it fails for the right reason, implementing minimal code to pass, then refactoring while staying green. - Anti-Rationalization Guardrails: Provides explicit rebuttals to common excuses like "I'll test after" or "deleting code is wasteful", plus red flags that signal when to delete code and start over. - Testing Anti-Pattern Reference: Covers testing mock behavior, test-only methods in production classes, mocking without understanding dependencies, and incomplete mocks. - Use Case: When fixing a bug where empty emails are accepted, write a failing test asserting the rejection error, watch it fail, add the minimal validation check, and confirm the full suite passes. ## 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.
