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Javascript Testing Expert

Checked
dubzzz·vlatest·backend·MIT

Helps with JavaScript, testing as part of developing backend services and APIs workflows.

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 dubzzz/fast-check --skill javascript-testing-expert -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

dubzzz

Taken from the source listing. We haven't verified who controls this account.

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.

    No base64, hex or compressed blob is decoded and then executed, and no encoded shell commands.

  • No credential access: passed

    Reads no keys, tokens, keychains or credential files.

    Neither the code nor the SKILL.md instructions read SSH keys, cloud credentials, keychains, token stores, browser cookie databases or dotfiles that hold secrets.

  • No pipe-to-shell installers: passed

    No pipe-to-shell or download-and-run installers.

    No `curl … | sh` pattern, in the code or in the instructions, that runs code fetched at run time.

  • Pinned to a commit: passed

    Scanned dubzzz/fast-check at f6f2d09619.

    The exact upstream commit SHA that was scanned is recorded, so the result refers to specific bytes.

Commit
f6f2d09619
Manifest
skills/javascript-testing-expert/SKILL.md
Scanned
1 file, 379 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.
What each check looks for →

About this skill

What it does

This skill leverages the fast-check library to generate random inputs and automatically verify JavaScript code against defined properties. It helps identify edge cases and regressions that manual testing often misses by exploring a vast space of data scenarios.

When to use it

  • You need to validate complex logic where input combinations are too numerous for manual coverage.
  • You want to ensure your code handles unexpected or malformed data gracefully.
  • You are refactoring existing JavaScript functions and need regression tests generated automatically.
  • You require property-based testing to mathematically prove invariants hold true across diverse inputs.

Key capabilities

  • Generates random test data based on specific type constraints (e.g., arrays, objects, numbers).
  • Executes tests against user-defined properties or assertions.
  • Automatically shrinks failing test cases to isolate the minimal input causing an error.
  • Integrates seamlessly with existing JavaScript development workflows.

Example prompts

  • "Generate a fast-check test suite for my calculateDiscount function that handles edge cases like negative prices and zero quantities."
  • "Write property-based tests to verify that my JSON parser never throws errors on valid input strings."
  • "Create a test case using fast-check to ensure my sorting algorithm maintains the relative order of equal elements."

Tips & gotchas

Ensure your assertions are precise; vague properties may lead to false positives or unhelpful test results. Familiarize yourself with fast-check's shrinker mechanism, as it is crucial for debugging failures by reducing complex failing inputs into simple, reproducible examples.