What problem does it solve? Code coverage tells you which lines ran during tests, but not whether tests would fail if the code were wrong. This Skill performs static pseudo-mutation analysis—reasoning about hypothetical code changes like boundary flips, boolean inversions, and removed null checks—to reveal blind spots where tests pass but would keep passing even if the code were broken. ## Core Features & Use Cases - Mutation Point Catalog: Identifies boundary, boolean, return value, exception, arithmetic, and null-check mutation points across .NET, Python, TypeScript/JavaScript, Java, Go, Ruby, Rust, Swift, Kotlin, PowerShell, and C++. - Kill/Survive Classification: Classifies each mutation as Killed, Survived, No coverage, or Equivalent, then prioritizes survived mutations by business risk rather than raw count. - Actionable Reporting: Produces a mutation score summary plus concrete recommended test assertions for every gap found. - Use Case: Point the Skill at a payment calculation module and its test files; it reports that flipping < to <= in a discount threshold would go undetected and recommends the exact boundary test to add. ## Quick Start Ask the AI to analyze whether the tests for a specific module would catch bugs by performing pseudo-mutation analysis on the production code and its test files.
