What problem does it solve?
This Skill eliminates the risk of writing fragile, implementation-coupled tests that break during code refactors, and avoids the inefficiency of horizontal TDD slicing that produces tests verifying imagined behavior instead of actual user-facing functionality.
Core Features & Use Cases
- Behavior-Focused Test Guidance: Enforces writing integration-style tests that verify public API behavior, ensuring tests remain valid even when internal code structure changes.
- Anti-Pattern Avoidance: Explicitly warns against common TDD mistakes like horizontal slicing and implementation-detail testing, guiding users to use efficient vertical tracer bullet cycles.
- Use Case: A software engineer adding a new ship combat system to the Subspace Infinity game can use this Skill to write a single test for the damage calculation behavior first, implement minimal code to pass the test, then refactor the combat logic without breaking existing test coverage.
Quick Start
Use the tdd skill to implement the new zone matchmaking feature by writing one passing test for the player pairing behavior before writing any implementation code.