secondsky/claude-skills · plugins/mutation-testing/skills/mutation-testing/SKILL.md

mutation-testing skillA

mutation-testing is agent-read markdown (skill) from secondsky/claude-skills: Validate test effectiveness with mutation testing using Stryker (TypeScript/JavaScript with Vitest or bun test via @hughescr/stryker-bun-runner) and mutmut (Python). Find weak tests that pass despite code mutations. Use to improve test quality..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add secondsky/claude-skills/mutation-testing@git:20260803.875f1a8
Exact content
mdr add secondsky/claude-skills/mutation-testing@sha256:ef325228876bba65

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_5xxlauvwzmx7mlja.svg)](https://markdownregistry.com/a/art_5xxlauvwzmx7mlja)

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Versions

versioncommittedcommitsizeaudit
git:20260803.875f1a8 latest2026-08-03 875f1a8 5,672 BA view · diff
git:20260303.7e67f1a2026-03-03 7e67f1a 5,672 BA view · diff
git:20260303.3b60bbf2026-03-03 3b60bbf 5,659 BA view · diff
git:20251224.ba827ce2025-12-24 ba827ce 4,270 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (5672 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

secondsky/claude-skills · 219 stars · license MIT · pushed 2026-09-17 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_5xxlauvwzmx7mlja
GET https://markdownregistry.com/api/v1/resolve?ref=secondsky/claude-skills/mutation-testing
GET https://markdownregistry.com/api/v1/blob/ef325228876bba659511a7435a9286b8632eaef4241e8133e624e386a5ab4609

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.