| name | tdd |
| description | Runs behavior-first test-driven development for implementation-plan feature slices. Use when building behavior, fixing a bug with a known seam, adding integration tests, or when a prompt asks for red-green-refactor. |
Test-Driven Development
Use one vertical slice at a time. Tests should verify behavior through public
interfaces, not private implementation shape.
Workflow
- Read the task row, Goal, domain docs, and existing nearby tests.
- Name the public seam: API route, domain service, repository contract, UI
journey, CLI, or runbook check.
- Write one failing test for one observable behavior.
- Implement only enough code to pass that test.
- Repeat for the next behavior.
- Refactor only while green; run the same validation after each structural move.
Guardrails
- Do not write all tests first and all implementation second.
- Do not test private helpers unless there is no better seam and the gap is
recorded.
- Prefer existing fixture and repository patterns over new test infrastructure.
- For weak or unclear legacy behavior, switch to
diagnose or
architecture-review before broad edits.
Closeout
Report the red/green evidence, final validation commands, and any behavior that
could not be pinned to a good seam.