---
title: "Property-Based Testing - Air Market"
description: "Hand-picked test cases only cover what you thought to try. Property tests describe a rule that should hold for every input and then hunt for one that breaks it. This helps you write those, add to one…"
canonical: "https://airmarket.ai/app/property-based-testing"
---

[Air Market](/) / [Developer Tools](/category/devtools) / Property-Based Testing

Skill by [Trail of Bits](/@trailofbits)

# Property-Based Testing

Test the whole input space, not the examples you thought of

## What this does

Hand-picked test cases only cover what you thought to try. Property tests describe a rule that should hold for every input and then hunt for one that breaks it. This helps you write those, add to ones you have, and work out whether a failing case is a genuine bug or just a badly stated rule. Not for binary fuzzing.

### Top 3 things it does for you

- Write property tests for a parser, encoder or validator
- Add cases to a test suite you already have
- Work out whether a shrunk counterexample is a real bug

## Information

**Property-Based Testing at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [Trail of Bits](/@trailofbits) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Size | 39 KB |
| Licence | CC-BY-SA-4.0 |
| Repository | [trailofbits/skills](https://github.com/trailofbits/skills/tree/04b241176fd9c10738a61df53d2c677c53e42990/plugins/property-based-testing/skills/property-based-testing) |
| GitHub stars | 6,823 (as of Nov 2026) |
| Installs | 7,751, counted by skills.sh (Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of Property-Based Testing and flagged nothing. AIR's verdict: **safe**.

**What Property-Based Testing's check was run against**

|  |  |
| --- | --- |
| Commit | 04b241176fd9c10738a61df53d2c677c53e42990 |
| Content hash | c13a7fcc36772c1c872efd047eeeb443d41865c93d080f38ca192dcb3324151b |
| Files read | [Browse the files at this exact commit](https://github.com/trailofbits/skills/blob/04b241176fd9c10738a61df53d2c677c53e42990/plugins/property-based-testing/skills/property-based-testing/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for Property-Based Testing](/security/property-based-testing)

## About Property-Based Testing

This writes, reviews and debugs property-based tests, across Hypothesis, fast-check, proptest, jqwik, rapid, and Echidna or Medusa for Solidity invariants.

It fits wherever tests should cover a whole input domain rather than 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. It also covers adding cases to an existing @given, fast-check or proptest suite, judging whether property tests you already have assert anything real, and telling a wrong property from a genuine bug once a generator has shrunk a counterexample.

It is not the tool for coverage-guided binary fuzzing with libFuzzer or AFL, for mutation-testing campaigns, for static analysis, for benchmarking, or for end-to-end UI tests.

## What's inside

- SKILL.md - instructions
- agents/openai.yaml - data
- assets/trail-of-bits-mark.svg - template
- README.md - reference
- references/generating.md - reference
- references/interpreting-failures.md - reference
- references/libraries.md - reference
- references/refactoring.md - reference
- references/reviewing.md - reference

## Questions

### Is Property-Based Testing safe to install?

AIR scanned this exact version of Property-Based Testing and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit 04b241176fd9, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/property-based-testing.

### How do I install Property-Based Testing?

Open https://airmarket.ai/app/property-based-testing on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/trailofbits/skills/tree/04b241176fd9c10738a61df53d2c677c53e42990/plugins/property-based-testing/skills/property-based-testing. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by Trail of Bits](/@trailofbits)

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Canonical URL: <https://airmarket.ai/app/property-based-testing>