Mutation Test Suite Optimizer

Overview

This skill optimizes test suites using mutation testing, selecting a minimal subset of tests that maximizes mutation kill rate while reducing execution time and redundancy.

Quick Start

# Optimize test suite with mutation testing
python scripts/optimize.py /path/to/repo --tests tests/

# Use specific mutation operators
python scripts/optimize.py repo/ --tests tests/ --operators AOR,ROR,COR

# Generate optimization report
python scripts/optimize.py repo/ --tests tests/ --output report.json

What Gets Optimized

1. Test Selection - Identify minimal test subset for maximum coverage
2. Redundancy Removal - Eliminate tests that kill same mutants
3. Mutation Coverage - Maximize mutants killed
4. Execution Time - Reduce overall test execution time
5. Test Quality - Identify weak or ineffective tests

Mutation Operators

Supports common mutation operators:

• AOR - Arithmetic Operator Replacement
• ROR - Relational Operator Replacement
• COR - Conditional Operator Replacement
• SOR - Shift Operator Replacement
• LOR - Logical Operator Replacement
• ASR - Assignment Operator Replacement

Optimization Report

Generates detailed report with:

• Optimized Test Suite - Minimal test subset
• Mutation Kill Rate - Percentage of mutants killed
• Killed Mutants - List of detected mutants
• Surviving Mutants - Mutants that escaped detection
• Redundant Tests - Tests that can be removed
• Execution Time Savings - Time reduction achieved

Example report:

{
  "original_tests": 150,
  "optimized_tests": 45,
  "mutation_kill_rate": 92.5,
  "killed_mutants": 185,
  "surviving_mutants": 15,
  "time_savings": "67%"
}

Usage

python scripts/optimize.py <repo_path> --tests <test_dir> [--operators <ops>] [--output <report.json>]

Tips

• Run regularly to maintain test suite quality
• Focus on high-value tests that kill unique mutants
• Remove redundant tests to speed up CI/CD
• Use surviving mutants to guide new test creation
• Balance mutation score with execution time
• Integrate into continuous testing pipeline