TRIGGER: TDD, SDD, test driven, spec driven, SPEC.yaml, RED GREEN REFACTOR, test coverage, delta spec, brownfield testing, write tests first. TDD+SDD dual-pyramid development workflow. SDD drives WHAT to build (SPEC.yaml), TDD drives HOW to verify it (RED-GREEN-REFACTOR with file-based evidence gates). Enforces spec-first development and mandatory test-failure evidence before implementation. 80% coverage hard threshold. Use for any code that needs tests, specs, or long-term maintainability. NOT for trivial fixes (< 5 lines) or documentation-only changes.
2026-04-18