verification-beyond-testslisted

# Verification beyond tests — five phases Unit tests prove the cases the author thought of. The cases nobody thought of remain unverified. This skill applies systematic verification methods to make the unverified surface smaller — without pretending to verify things that aren't verifiable. ## When to use You're authoring `stage-06d` (verifier role). Stage-06 (qa) already returned PASS — the floor is in place. The track is `full`, so the expectation is rigour over speed. Your task: pick the right method per candidate, apply it, surface findings. ## Phase 1 — Inventory candidates Scan the diff. For each function/module, classify against the methods: | Code shape | Method | |---|---| | Pure functions over structured data — parsers, validators, codecs, transforms, sort/dedupe, math, normalisation | **Property-based** | | Custom formatters, serializers, or encoders over user-controlled data — logging formatters, structured log schemas, metric label builders, trace attribute setters | **Property-based** (valid-output invariant: output is parseable/well-formed for all inputs up to the field's documented max) | | Critical business logic with example tests — auth, billing, anything with a real test suite | **Mutation** | | Concurrent state machines, distributed protocols, consistency invariants, security properties | **Formal** | | Glue, UI, CRUD with thin logic | **Skip with reason** | Write the inventory as a table in the report. Be honest about glue — applying mutation to a