# Property Based Testing

> Writes, reviews, and debugs property-based tests — Hypothesis, fast-check, proptest, jqwik, rapid…

Writes, reviews, and debugs property-based tests — Hypothesis, fast-check, proptest, jqwik, rapid, and Echidna or Medusa for Solidity invariants. Use whenever tests should cover a whole input domain instead of a hand-picked list of examples: encode/decode and serialize/deserialize pairs, parsers, canonicalizers and normalizers, validators, numeric and Decimal types, comparators and sort order, data structures, and smart-contract state invariants. Also use when adding cases to an existing @given, fast-check, or proptest suite, when judging whether existing property tests assert anything real, and when a generator has shrunk a counterexample and you need to tell a wrong property from a genuine bug. Not for coverage-guided binary fuzzing (libFuzzer, AFL), mutation-testing campaigns, static analysis, benchmarking, or end-to-end UI tests.

- Page: https://ss33.ai/skills/trailofbits/property-based-testing-55737295884
- Publisher: trailofbits
- Category: [Software Development](https://ss33.ai/skills/category/software-development-t44z8z) › [Testing & QA](https://ss33.ai/skills/category/software-development-t44z8z/testing-and-qa-g56s6z)
- Source: https://github.com/trailofbits/skills/blob/5c99c03fb8a9ea568432ecbcba5d86e9f4ac2bf0/plugins/property-based-testing/skills/property-based-testing/SKILL.md

## Skill

This skill's licence does not allow redistribution, so the store does not serve its text. Get it from the author: https://github.com/trailofbits/skills/blob/5c99c03fb8a9ea568432ecbcba5d86e9f4ac2bf0/plugins/property-based-testing/skills/property-based-testing/SKILL.md