What problem does it solve? Code changes made without tests ship unverified behavior, and bug fixes without reproduction tests leave regressions unguarded. This Skill enforces a disciplined workflow where every behavior change is proven by a failing-then-passing test before it is considered done. ## Core Features & Use Cases - Red-Green-Refactor Loop: Write a failing test first, implement the minimal code to pass it, then refactor with tests staying green. - Prove-It Pattern for Bug Fixes: Reproduce any reported bug with a failing test before attempting a fix, guaranteeing the fix actually works. - Stack Discovery: Detects the repository's own test framework and commands (npm, Gradle, pytest, Cargo, Go) instead of assuming defaults. - Test Quality Guidance: Covers the test pyramid, DAMP over DRY, state-based assertions, and preferring real implementations over mocks. - Use Case: A bug report says completing a task doesn't set its timestamp. The Skill guides the agent to write a failing reproduction test, implement the fix, confirm the test passes, and run the full suite for regressions. ## Quick Start Ask the agent to implement a new feature or fix a bug using test-driven development, writing a failing test first and proving the fix with a passing test.
