test-driven-development

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 cycle of writing a failing test, verifying the failure, writing minimal passing code, and refactoring safely. - Rationalization Detection: Lists common excuses for skipping TDD (e.g., "too simple to test", "I'll test after") with concrete rebuttals and red flags that trigger a restart. - Testing Anti-Pattern Reference: Covers mock-behavior testing, test-only production methods, 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 Use the test-driven-development skill to implement this feature by writing a failing test first, then the minimal code to make it pass.