Hardening

• Every property written states the universal claim behind existing example tests, runs across generated inputs drawn from the function's real input domain, and keeps the examples it sharpens.
• Every failure ends shrunk to a minimal counterexample with its seed, and ends in either a fixed bug or a corrected property.
• What hardening lands is recorded where the system reads it: a bun-property row in the ISA's Test Strategy, and a C/R/L Learning entry when a counterexample taught something.
• Functions that cannot carry a universal claim (impure, or no candidate shape) are left to example tests rather than forced into a property.

• Testing Doctrine Rule #12 — names fast-check as the property-testing primitive (LIFEOS/DOCUMENTATION/Testing/TestingDoctrine.md).
• ISA format — the bun-property ISC type with property | generator | runs columns (LIFEOS/DOCUMENTATION/ISA/ISAFormat.md § ISC Type Vocabulary). A bun-property row is a first-class assert: it counts toward every-ISC-an-assert coverage (H8) and bunker test runs it like any deterministic row.
• Algorithm — hardening is elected during verification when a run's criteria warrant property depth; spend is discovered from the work.
• System prompt — Verification Is the Mechanism section at top (LIFEOS/LIFEOS_SYSTEM_PROMPT.md).

The Bunker CLI is maintainer-private and not in the public release; run code rows with bun test ./<path> and suite rows with bun skills/Assay/Tools/EvalRunner.ts.

No skill-wide gotchas; the fast-check ones live in Intents/PropertyTest.md § Gotchas.

• "Property-test the slug parser" → PropertyTest → round-trip and idempotence properties in a .property.test.ts file at 1000 runs, a bun-property row in the ISA, and any failure shrunk with its seed pinned.
• "What bugs are my example tests missing?" → PropertyTest → the pure functions (parsers, serializers, transforms) that have only example coverage, listed as property-test candidates.