How do I install the Mutation Test skill?

Run npx skillmds add majiayu000/mutation-test-2 in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Mutation Test skill do?

Run mutation testing to validate test suite quality It is listed under Coding & Dev Tools on SkillMD.

Is Mutation Test safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: docs only. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Mutation Test?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Mutation Test free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Mutation Test?

majiayu000 (@majiayu000) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Mutation Test by majiayu000 — Agent Skill

Name: Mutation Test
Rating: 4.666666666666667 (3 reviews)
Author: majiayu000

File contents

Mutation Testing with Stryker

Run mutation testing to verify your test suite actually catches bugs.

For .NET (Stryker.NET)

dotnet tool install -g dotnet-stryker
cd src/backend/Tests/MatchingServiceTests
dotnet stryker

Configure stryker-config.json:

{
  "stryker-config": {
    "project": "CandidateMatchingEngine.csproj",
    "mutate": ["**/Services/**/*.cs", "!**/Generated/**"],
    "thresholds": { "high": 80, "low": 60, "break": 40 },
    "reporters": ["html", "json", "progress"],
    "concurrency": 4
  }
}

For TypeScript/JavaScript (StrykerJS)

npx stryker init
npx stryker run

Interpreting Results

Killed: Test caught the mutation (GOOD)
Survived: Tests missed the change (BAD -- add tests)
Mutation score = killed / (killed + survived) -- target >60%

CI Integration

- script: dotnet stryker --threshold-break 40
  displayName: "Mutation Testing"
  condition: eq(variables['Build.Reason'], 'PullRequest')

Arguments

--project=<path>: Path to test project
--threshold=<n>: Break build if score below this (default: 60)

Frequently asked questions