Find the commit that introduced a regression automatically with git bisect run.
Configure Jest for a TypeScript project — ts-jest, module mapping, and coverage thresholds.
Diagnose a slow Postgres query and add the right index using EXPLAIN ANALYZE.
Test React components with Testing Library — render, query by role, and assert on user-visible behavior.
Fix TypeScript ES module import errors by adding .js extensions to relative imports.
Migrate a Jest test suite to Vitest — config, globals, and mock API differences.
Comprehensive guide for creating high-quality skills for Claude. Use when building a new skill, writing a SKILL.md, designing skill frontmatter, planning skill structure, debugging trigger issues, or reviewing an existing skill for improvements. Covers standalone skills, MCP-enhanced skills, and skill-tree programmatic skills.
Helps write clear and conventional git commit messages.