What problem does it solve? Teams practicing test-driven development need tests written before any implementation exists, and those tests must fail for the right reason (missing implementation, not syntax errors). This Skill enforces strict TDD discipline by generating comprehensive failing tests that define the expected behavior of a feature upfront. ## Core Features & Use Cases - Test-First Authoring: Writes happy path, edge case (empty input, boundaries, nulls), and error case tests against the real, not-yet-existing public API. - Failure Verification: Runs the tests to confirm they fail because the implementation is missing, not because of test bugs, and never mocks the unit under test. - Parallel Test Generation: Spawns subagents to write multiple test files in parallel, coordinating to avoid duplicate setup. - Use Case: Given a feature spec for a new API endpoint, the Skill produces a complete test suite covering valid inputs, boundary conditions, and failure modes, then hands it off to an implementer agent once the tests fail correctly. ## Quick Start Ask the agent to write failing TDD tests for the feature described in your spec or issue before any implementation begins.
