What problem does it solve? Developers often write code first and tests later (or never), leading to regressions, untested edge cases, and low confidence when refactoring. This Skill enforces a strict test-first workflow so every feature, bug fix, or refactor ships with meaningful Jest tests and at least 80% line coverage on changed code. ## Core Features & Use Cases - Structured TDD Workflow: Guides you through acceptance criteria, failing tests, minimal implementation, refactoring, coverage verification, and a clean build. - Test Quality Rules: Prevents common anti-patterns like self-testing tests, trivial assertions, wildcard mock matchers, and duplicate tests that should be parameterized. - Testability Guidance: Shows how to structure services, repositories, and controllers so business logic is directly testable without heavy framework plumbing. - Use Case: When adding a new API endpoint to the mahjong game service, the Skill walks you through writing failing Jest tests for the service method first, implementing the minimal code, verifying mock interactions, and confirming 80%+ coverage before building. ## Quick Start Ask the AI to implement a new feature or fix a bug using the tdd-workflow skill so tests are written before any production code.
