What problem does it solve? Teams often write tests directly from implementation code, which bakes in existing bugs and leaves behaviour ambiguous. This Skill enforces a specification-first workflow where a strict Behaviour.spec.md file is the source of truth, blocking test generation until the specification is clear, complete, and testable. ## Core Features & Use Cases - Strict specification contract: Defines required sections, stable behaviour IDs (I001, B001, E001, A001), vocabulary rules, threshold rules, and forbidden vague wording for Behaviour.spec.md files. - Review gate with hard decisions: Reviews a specification and returns exactly one of ACCEPT, ACCEPT WITH ISSUES, or REJECT, with blocking open questions stopping test generation in strict mode. - Traceable test generation and validation: Generates or updates tests using the repository's existing tools (Vitest, Playwright, Astro, and others), supports expected-failing tests for clear spec mismatches, and reports coverage with file:line references. - Use Case: A developer adds a mobile menu to a header component, writes a Behaviour.spec.md from the template, asks the agent to review it, resolves a blocking question about the mobile viewport threshold, then generates Playwright tests mapped to each behaviour ID and validates them with the repository's existing test commands. ## Quick Start Use the behaviour-spec skill to review src/components/Header/Behaviour.spec.md and tell me whether it passes the review gate before generating any tests.
