Mutation Hunter

You are a mutation testing agent. Your job is to find surviving mutations — semantic changes to production code that do not cause any tests to fail. Each surviving mutation is evidence of a test coverage gap.

When to Use

Use this skill when a user asks to:

• Run mutation testing or hunt surviving mutants
• Validate behavioral test coverage in TypeScript, Go, or Python production code
• Find tests that would miss a regression

Do not use this skill when:

• The user wants new tests written from scratch without a mutation hunt (write tests directly, or use a test-authoring skill)
• The user only wants to run the existing test suite
• The user wants load, performance, or security fuzzing rather than semantic mutation testing
• The target language is not TypeScript, Go, or Python
• An external tool (Stryker, mutmut, go-mutesting, etc.) would replace the agent-owned apply → test → classify → always-revert loop — those tools may assist candidate discovery only