Stryker Mutation Testing

SkillDev tools

Stryker mutation testing for assessing test suite quality and effectiveness

Instructions available. Your AI can read the instructions. Execution depends on the setup they require.

Add ahel to your AI once: Claude, ChatGPT, Cursor, Claude Code or Codex. Then ask it to use this.

Then ask your AI: use the Stryker Mutation Testing skill

What this skill tells your AI

The instructions your AI receives, as published by a5c-ai/babysitter in library/specializations/qa-testing-automation/skills/stryker-mutation/SKILL.md and read by ahel’s review.

Overview

This skill provides expert-level capabilities for Stryker-based mutation testing, enabling test quality assessment by introducing code mutations and measuring test effectiveness.

Capabilities

Mutation Execution

  • Configure Stryker for JavaScript/TypeScript
  • Execute mutation testing runs
  • Configure mutation operators

Score Analysis

  • Analyze mutation score
  • Track killed vs survived mutants
  • Identify weak test assertions

Configuration

  • Configure mutators and test runners
  • Set up file patterns for mutation
  • Configure timeout settings

Reporting

  • Generate HTML mutation reports
  • Dashboard integration for tracking
  • CI/CD report generation

Optimization

  • Configure incremental mutation testing
  • Optimize mutation runs for large codebases
  • Parallel mutation execution

Test Quality Insights

  • Identify gaps in test coverage
  • Recommend assertion improvements
  • Prioritize test enhancements

Target Processes

  • mutation-testing.js - Mutation testing implementation
  • quality-gates.js - Mutation score gates
  • shift-left-testing.js - Early test quality validation

Dependencies

  • @stryker-mutator/core - Stryker core
  • Test runner plugins (jest-runner, karma-runner)
  • Reporter plugins

Usage Example

{
  kind: 'skill',
  skill: {
    name: 'stryker-mutation',
    context: {
      action: 'execute',
      configFile: 'stryker.conf.json',
      mutate: ['src/**/*.ts'],
      thresholds: {
        high: 80,
        low: 60,
        break: 50
      }
    }
  }
}

Configuration

The skill uses stryker.conf.json or stryker.conf.js and supports incremental testing for faster feedback.

Signals

GitHub stars
2k
Forks
112
Last commit
Sep 2026
Advanced
Item type
skill
Key
stryker-mutation-testing
Source
github.com/a5c-ai/babysitter