Setup Pre Commit

Setup Pre-Commit Hooks

What This Sets Up

• Husky pre-commit hook
• lint-staged running Prettier on all staged files
• Prettier config (if missing)
• typecheck and test scripts in the pre-commit hook (if they exist)

Workflow

1. Detect package manager from lock file: package-lock.json (npm), pnpm-lock.yaml (pnpm), yarn.lock (yarn), bun.lockb (bun). Default to npm if unclear.

1. Install devDependencies:

`` husky lint-staged prettier ``

1. Initialize Husky:

``bash npx husky init ` This creates .husky/ dir and adds prepare: "husky"` to package.json.

1. Create .husky/pre-commit (no shebang needed for Husky v9+):

`` npx lint-staged run typecheck run test ` Replace with detected package manager. If repo has no typecheck script in package.json, omit that line and tell the user. Same for test`.

1. Create .lintstagedrc:

``json { "*": "prettier --ignore-unknown --write" } ``

1. Create .prettierrc (only if no Prettier config exists):

``json { "useTabs": false, "tabWidth": 2, "singleQuote": true, "trailingComma": "all" } ``

1. Verify:

• .husky/pre-commit exists and is executable
• .lintstagedrc exists
• prepare script in package.json is "husky"
• Prettier config exists
• Run npx lint-staged to confirm it works

1. Commit all changed/created files: Add pre-commit hooks (husky + lint-staged + prettier)

This runs through the new pre-commit hooks -- a good smoke test.

Rules

• Never overwrite existing Prettier config
• Never overwrite existing .husky/pre-commit without asking user first
• Always use detected package manager consistently
• Husky v9+ doesn't need shebangs in hook files
• prettier --ignore-unknown skips files Prettier can't parse (images, etc.)
• Pre-commit runs lint-staged first (fast, staged-only), then full typecheck and tests

Error Handling

• No package.json found -- report and stop
• Existing .husky/pre-commit -- ask user before overwriting
• husky init fails -- check node_modules exists, suggest running install first
• npx lint-staged verification fails -- check Prettier is installed, check .lintstagedrc syntax
• No typecheck or test scripts -- omit from hook, tell user which were skipped

See Also

• [validate-code](../validate-code/SKILL.md) -- run lint/typecheck/tests manually
• [commit](../commit/SKILL.md) -- create git commits following repo style

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: helderberto
• Source: helderberto/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.