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Real file from a public repo · synced Sep 3, 2026

property-based-testing

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.

trailofbits/skills5.3k installs

Works with

Claude CodeCursorCodex CLIGitHub CopilotGemini CLI

Install in three steps

  1. 1

    Download the ZIP

    One file per agent, plus INSTALL.md with the exact paths below.

  2. 2

    Claude Code: copy SKILL.md into your skills folder

    .claude/skills/property-based-testing-l8k7gg/SKILL.md    # this project
    ~/.claude/skills/property-based-testing-l8k7gg/SKILL.md   # every project
  3. 3

    Other agents: use the matching file

    skill.mdc goes in Cursor’s .cursor/rules/. AGENTS.md works as GitHub Copilot instructions, a legacy .cursorrules, or a Codex / Gemini CLI instructions file.

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