What problem does it solve? Code changes made without tests first often ship with untested behavior, brittle retroactive tests, and regressions that surface only in production. This Skill enforces a strict red-green-refactor discipline so every executable code change is verified by a failing test before implementation begins. ## Core Features & Use Cases - Tracer-bullet TDD cycle: Write one failing test, verify it fails for the right reason, then write the minimal implementation, repeating in vertical slices rather than batching all tests up front. - 10-point test quality rubric: Validates that tests assert observable behavior, are deterministic, non-vacuous, properly named, and mock only at system boundaries. - Explicit waiver system: Permits only four documented waiver phrases for non-code, type-only, config-only, or ADR-only changes, blocking vague excuses like "small change" or "obvious fix". - Use Case: When asked to fix a bug in an authentication service, the Skill requires writing a failing regression test first, confirming it fails for the right reason, applying the minimal fix, then running the full unit and integration suites before declaring completion. ## Quick Start Implement this feature using the tdd-workflow skill, writing a failing test first and then the minimal code to make it pass.
