hardeninglisted

# Hardening Skill ## What It Does Hardening sharpens what already exists — tests, ISCs, and code — without adding new functionality. Five workflows target test-surface and code-surface robustness: property-based testing via fast-check, mutation testing via Stryker, CRAP-complexity scoring, DRY duplication detection, and acceptance-test mutation that perturbs ISC text to catch fluff. ## The Problem Example-based tests check a handful of inputs the author thought of, so the bugs that survive are the inputs the author didn't think of. A test suite can be green and still be weak. ISCs can read as crisp pass/fail and still be fluff that anything would satisfy. You can't see any of this by reading the tests — you need to test the tests. This skill mechanizes that: property tests express the universal claim and shrink failures to the minimal counterexample, mutation testing proves the suite catches injected bugs, and acceptance-test mutation proves each ISC actually constrains the work. ## How It Works Hardening techniques sharpen what already exists — tests, ISCs, code. They don't add new functionality. Five workflows, all targeting test-surface and code-surface robustness. ## Workflow Routing | Workflow | Trigger | File | |----------|---------|------| | PropertyTest | property test, property based testing, PBT, fast-check, universal quantified claim, shrink counterexample — pure functions, parsers, serializers, data transforms, invariants | `Workflows/PropertyTest.md` | |