Mutant Killers — Testing skill for Claude Code
Act as a rigorous senior Perl SDET specializing in mutation testing.
How to install Mutant Killers
Installs to ~/.claude/skills/nigelhorne-claude-mutant-killers/SKILL.md
mkdir -p ~/.claude/skills/nigelhorne-claude-mutant-killers && curl -fsSL https://raw.githubusercontent.com/nigelhorne/claude/HEAD/commands/mutant-killers.md -o ~/.claude/skills/nigelhorne-claude-mutant-killers/SKILL.md Restart Claude Code, or start a new session, for it to be picked up.
What Mutant Killers does
Act as a rigorous senior Perl SDET specializing in mutation testing. Write a comprehensive set of tests in `./t/mutant_killers.t` to explicitly kill the mutants described in the most recent stub file located in `./xt/`.
PRE-REQUISITE: STUB ANALYSIS
- Locate and parse the most recent auto-generated stub file (
xt/mutant_*.t) created byApp::Test::Generator. - Ensure tests enforce what the code should do (intended behavior), not what it currently does.
TEST ARCHITECTURE & LIBRARIES
- If
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Full documentation available on GitHub
View Source RepositoryRelated Skills
Function Test
Act as a rigorous senior Perl SDET. Write a comprehensive set of white-box subtests in ./t/function.t to valid
Crash Analyzer
Act as a senior Perl debugging expert. Analyze the provided source code alongside the accompanying stack trace
Test Review
Write-then-verify test review — write tests in your normal flow, then mechanical gates (red-green + mutation)
Qspec
Write a spec for the described feature. Follow the Spec-Driven Development standards from the coding-standards
Mmut
Run mutation testing to validate unit tests
Builder Implement
Builder step 3 — implement the fix described in the spec
Related Agents
Mutation Analyst
Analyses test suite strength via Stryker.NET mutation testing and reports surviving mutants
Mutation Hardener
Dual-mode mutation-testing agent. AUDIT mode runs the mutation tool over a scope and reports surviving mutants
Mutation Tester
Optional quality audit. Runs mutation testing (or reasons about mutants by hand where no tool exists) to find