SKILL.md
Test-Driven Development
<!-- source-of-truth: test-first implementation at public seams. --> <!-- doc-meta: owner=eng | last-reviewed=2026-09-01 -->
Process skill — red → green microcycle. Tests at public interfaces only. Shared vocabulary → process-skill-composition.md.
References: [anti-patterns.md](references/anti-patterns.md) · [output.md](references/output.md) · codebase-design.md.
Read [research-basis.md](references/research-basis.md) only when you calibrate seam claims.
Entry gate
- Seam agreed with the user — public interface under test (
Seam:header or explicit agreement). - Slice in scope — path glob or module id shared with other active atoms when layered.
- If there is no agreed seam, stop and ask. Do not write production code or tests at private helpers only.
Non-negotiables
- Red before green — one vertical slice per cycle.
- Independent expected values — not tautological to production logic.
- Refactor out of scope — defer structural cleanup unless the user asks.
Workflow
- Make sure that Seam and Slice are agreed.
- Failing test → red → minimal green → stop.
- Report per [output.md](references/output.md). User-facing report uses pragmatic STE.
Exit artifact
Per [output.md](references/output.md) — seam, cycle summary, test path citations.
Consumer bindings
Project-specific injected context is appended on skill read. Do not edit synced copies in place.
Output format
Follow output-schema.md. Details → [references/output.md](references/output.md).