ptp-test-driven-development

Invoke this skill before writing implementation code so the agent writes one failing test per behavior, verifies it fails for the intended reason, then writes the smallest change to pass. Code written before its test is deleted and rewritten from the test.

Write one test asserting the real behavior, run it to confirm it fails for the intended reason, make the smallest change that passes, verify the whole suite stays green, then refactor only while green. A test that passes immediately is testing something that already exists.

Yes, under the prose-contract exemption you record `RED: not applicable — prose contract` and name the bound reader, but you must still run every available check such as `openspec validate --strict`. The exemption never applies when the change also touches executable code.

jsdom implements no cascade and no layout engine, so it cannot fail for the reason a real browser would on render-affecting tasks. The RED test must run in a real browser engine such as Playwright or vitest browser mode and assert computed style via getComputedStyle.

No. Advisory relaxes the blocking gate but not the discipline: the cycle is still followed and the `tests` evidence entry is recorded in the apply stage record. Advisory is not silence.