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Property Based Testing

Checked
aj-geddes·vlatest·testing·MIT

Generates test cases based on property specifications to verify software behavior and uncover edge case failures.

Repository

Install on your platform

Showing Claude Code. One command installs this skill into any of the agents below.

  1. 1

    Run this in your project

    terminal
    $ npx skills add aj-geddes/useful-ai-prompts --skill property-based-testing -a claude-code

  2. Uses the open-source skills CLI and needs Node.js. Add -g to install it for your user instead of this project.

What we know about this skill

Publisher

aj-geddes

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Install target

Live repository

Not pinned. Installing fetches whatever the repository holds at the time you run the command.

No human has reviewed this code. The checks below are a static scan of the files at one commit — nobody has run this skill or judged whether it works. A skill runs with whatever access you give your agent, so read the source before you install it.

Automated safety checks

scanned

This skill passed all 6 checks. We read its files at one commit and looked for the things that make a skill dangerous to run — not for whether it works.

  • Declares what it does: passed

    SKILL.md parses and declares a name and a description.

    SKILL.md exists, its frontmatter parses, and it declares a name and a description.

  • No undeclared network calls: passed

    Makes no network calls.

    Every host the skill dials — from its scripts, its config endpoints or the commands it tells the agent to run — is either well-known package and API infrastructure or declared in its own frontmatter. Links in documentation are not counted.

  • No obfuscated payloads: passed

    No encoded or obfuscated payloads.

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  • No credential access: passed

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  • Pinned to a commit: passed

    Scanned aj-geddes/useful-ai-prompts at 3f5182cfd7.

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Commit
3f5182cfd7
Manifest
skills/property-based-testing/SKILL.md
Scanned
6 files, 603 lines
This is a static scan, not a review. It reads the skill's files; it does not run them, and it cannot tell you whether the skill is any good or whether the code does what its description says. A skill runs with whatever access you give your agent.
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About this skill

What it does

This skill enables AI agents to generate and execute property-based tests, verifying that code adheres to logical invariants rather than just specific input-output pairs. It automates the creation of diverse test cases to uncover edge cases and subtle bugs that traditional unit testing often misses.

When to use it

  • Validating complex data transformation logic where inputs vary widely.
  • Ensuring mathematical functions or algorithms maintain consistency across boundary conditions.
  • Testing stateful systems to verify invariants hold true regardless of execution order.
  • Strengthening test coverage for codebases with difficult-to-reach edge cases.

Key capabilities

  • Automatically generates random inputs to stress-test functions.
  • Checks if outputs satisfy defined logical properties or constraints.
  • Shrinks failing test cases to minimal counter-examples for easier debugging.
  • Integrates seamlessly into existing CI/CD pipelines for continuous verification.

Example prompts

  • "Generate property-based tests for a function that calculates the median of an array, ensuring it handles empty lists and single elements correctly."
  • "Create a test suite that verifies a sorting algorithm maintains the relative order of equal elements (stability) using random data."
  • "Write properties to validate that a date validation function always returns a boolean and never throws errors for valid ISO strings."

Tips & gotchas

Property-based testing requires clearly defined invariants; vague constraints lead to ineffective tests. While powerful, it may not replace the need for specific unit tests covering known business logic paths.