mutation-test

# Mutation Testing Skill

Run mutation testing to identify weak tests through semantic code mutations and parallel test execution.

## Quick Start

```bash
/mutation-test stripe_handler.py              # Standard mode (15 mutations)
/mutation-test --quick api/payments/          # Quick mode (5 mutations)
/mutation-test --deep billing/                # Deep mode (30+ mutations)
/mutation-test                                # Smart mode (auto-detects target)
```

### No Path Provided? Smart Detection!

When invoked without a path (`/mutation-test`), the agent will:

1. **Check conversation context** - If discussing a specific file, test that file
2. **Check git status** - Find recently modified files that have tests
3. **Ask the user** - Present options if multiple candidates found

Example:
```bash
User: /mutation-test

Agent: "I found several recently modified files with tests:
1. stripe_handler.py (modified 5 min ago, 200 tests)
2. payment_processor.py (modified 1 hour ago, 50 tests)

Which would you like to mutation test?"
```

## What is Mutation Testing?

Mutation testing is the gold standard for measuring test quality. It works by:

1. **Creating mutations** - Making small, realistic changes to your code (introduce bugs)
2. **Running tests** - Execute your test suite against each mutation
3. **Measuring results** - Count how many mutations your tests caught
4. **Identifying zombies** - Find tests that pass even when code is broken

**Traditional coverage is misleading**: 100% line coverage ≠ good tests

**Mutation score is truth**: % of realistic bugs your tests actually catch

## Modes

### Quick Mode (--quick)
- 5 mutations
- ~1-2 minutes
- Good for: Fast feedback, iterative development, pre-commit checks

### Standard Mode (default)
- 15 mutations
- ~3-5 minutes
- Good for: Normal development workflow, feature testing

### Deep Mode (--deep)
- 30+ mutations
- ~10-15 minutes
- Good for: Critical code paths, pre-release audits, comprehensive analysis

## What