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TESTING AND RELIABILITY / Trail of Bits

Trail of Bits Property-Based Testing

Chooses meaningful invariants and generators for tests that explore an input domain, while rejecting tautological or vacuous assertions.

“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”

01 / THE REASONING

Why this made the selection.

  • Explains how tests can pass while restating implementation or filtering away nearly every input.
  • Connects generator design to round trips, independent oracles and explicit boundary examples.

02 / THE REVIEW RECORD

What we actually inspected.

Source review has boundaries.
A clear record is more useful than a “safe” badge.

Material inspected

  • plugins/property-based-testing/skills/property-based-testing/SKILL.md
  • plugins/property-based-testing/skills/property-based-testing/references/generating.md
  • plugins/property-based-testing/skills/property-based-testing/references/refactoring.md
  • LICENSE

Our findings

  • The generator reference encodes constraints in strategies instead of relying on broad assume filters.
  • The refactoring reference suggests exposing pure calculations and preserving existing API behavior and tests.
  • The definition accepts example tests as the right outcome when no meaningful property justifies the extra machinery.

Not established by this review

  • Source inspection only; no skill installation or workflow execution was performed.

The review applies to the material and revision named here. A newer upstream release can change its behavior.

03 / PUT IT TO WORK

Add a skill to your workflow.

Upstream setup instructions ↗
  1. Install the complete property-based-testing plugin, including its agents, workflows and references.
  2. Claude Code: add the trailofbits/skills marketplace with /plugin marketplace add trailofbits/skills, then select the plugin in /plugin menu.
  3. The publisher also documents Codex marketplace compatibility; confirm the required workflow and delegation capabilities in the chosen host.

Before you start

  • A supported Claude Code or Codex plugin host
  • Permission for the plugin’s repository reads, outputs and any requested test commands
  • A behavioral contract and existing project test setup

04 / FOLLOW THE EVIDENCE

The source trail.

Our notes are separate from the original resource.
Check upstream before adopting a new version.

  1. https://github.com/trailofbits/skills/blob/123037ec8aed26f0d86327cc39137ee5043e5deb/plugins/property-based-testing/skills/property-based-testing/SKILL.md

    Supports: summary, upstreamDescription, whySelected, bestFor, limitations, review, compatibility, access

  2. https://github.com/trailofbits/skills/blob/123037ec8aed26f0d86327cc39137ee5043e5deb/plugins/property-based-testing/skills/property-based-testing/references/generating.md

    Supports: review, limitations, access

  3. https://github.com/trailofbits/skills/blob/123037ec8aed26f0d86327cc39137ee5043e5deb/plugins/property-based-testing/skills/property-based-testing/references/refactoring.md

    Supports: review, limitations, access

  4. https://github.com/trailofbits/skills/blob/123037ec8aed26f0d86327cc39137ee5043e5deb/LICENSE

    Supports: license

  5. https://github.com/trailofbits/skills/blob/123037ec8aed26f0d86327cc39137ee5043e5deb/README.md

    Supports: install, compatibility, access

  6. https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md

    Supports: install