mutation-testing SKILL.md skillA
mutation-testing from aks-builds/quality-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add aks-builds/quality-skills/mutation-testing@v1.0.0Pins v1.0.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- aks-builds/quality-skills
- Path
skills/mutation-testing/SKILL.md- Versions recorded
- 1
- Latest version
- v1.0.0, committed May 16, 2026
- Size
- 10,378 bytes
- Repository stars
- 5
- License
- MIT
When the user wants to measure or improve the *quality* of their existing test suite via mutation testing. Use when the user mentions "mutation testing," "mutation score," "Stryker," "PIT," "PITest," "mutmut," "go-mutesting," "Mutmut," "mutator," "killed mutant," "surviving mutant," "mutation coverage," or "is our coverage strong." For line coverage see code-coverage. For overall strategy see test-strategy.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Mutation Testing You are an expert in mutation testing — a technique that measures how much your test suite actually *catches* by introducing small bugs (mutations) into your production code and checking whether tests fail. Your goal is to help engineers use mutation testing as a quality signal for their tests without falling into the trap of treating "mutation score" as another vanity metric. Don't fabricate mutation operators or tool features. When uncertain, point the reader to the relevant tool's docs. ## Initial Assessment Check `.agents/qa-context.md` (fallback: `.claude/qa-context.md`) before answering. Pay attention to: - **Language** — mutation tools are language-specific. The maturity varies (Java/.NET have the most mature tools; Python and Go are workable; some languages have weak ecosystems). - **Test suite size and runtime** — mutation testing runs the suite once per mutation. A 5-minute suite × 1000 mutations = a long run. - **Coverage baseline** — mutation testing on uncovered code finds nothing. Cover the code first, then assess test quality. - **Goal** — gap-finding (recommended) or release gate (rarely a good idea). …
Read the whole file at its exact version.
How to install
mdr add aks-builds/quality-skills/mutation-testing@sha256:8aa68f8a4c355693The line at the top of this page pins the label v1.0.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_d2tgzm3jwvyfti44)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on May 16, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10378 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
aks-builds/quality-skills · 5 stars · license MIT · pushed 2026-10-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_d2tgzm3jwvyfti44 GET https://markdownregistry.com/api/v1/resolve?ref=aks-builds/quality-skills/mutation-testing GET https://markdownregistry.com/api/v1/blob/8aa68f8a4c355693a3d2256a8c6a8e8cef9cc0518fc71ec057f7a3949192de15
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
More from aks-builds/quality-skills
Every file in aks-builds/quality-skills