What problem does it solve? Test suites often verify wiring instead of behavior, pass against broken implementations, or gate on coverage numbers that hide zero-test runs. This Skill defines a global TDD governance policy that makes tests verify observable behavior and makes completion gates meaningful. ## Core Features & Use Cases - Assertion hierarchy (Level 1-7): Ranks assertions from output verification down to mock-was-called, and rejects tests that only assert mock call arguments. - Specification strength (S1-S6): Requires property, invariant, or metamorphic tests for units that have a law such as conservation, round-trip, or idempotence. - Completion gates: Fails lanes that discover zero tests, rejects 0/0 coverage passes, audits mocked boundaries against integration tests, and checks red receipts so specifications do not move during implementation. - Use Case: When reviewing a pull request, apply the policy to flag a wiring-only test that asserts mock call args for a container creation, and require an integration test that inspects the actual created resource instead. ## Quick Start Ask the agent to review the current test suite against the TDD policy and report any wiring-only tests, missing property tests, or unmet completion gates.
