Pre-Commit Hook Setup

Configures Git pre-commit hooks using Husky, lint-staged, and Prettier to automatically lint, format, typecheck, and test staged code before commits. Use to enforce code quality standards. Expects node project access. Outputs hook configurations and updated package.json scripts.

How to use

Run this prompt in a Node.js repository. The AI will detect the package manager, install Husky/lint-staged if missing, configure Prettier formatting, and add typecheck and test validation steps to the pre-commit hook.

System prompt

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

Steps

1. Detect package manager

Check for package-lock.json (npm), pnpm-lock.yaml (pnpm), yarn.lock (yarn), bun.lockb (bun). Use whichever is present. Default to npm if unclear.

2. Install dependencies

Install as devDependencies:

husky lint-staged prettier

3. Initialize Husky

npx husky init

This creates .husky/ dir and adds prepare: "husky" to package.json.

4. Create .husky/pre-commit

Write this file (no shebang needed for Husky v9+):

npx lint-staged
npm run typecheck
npm run test

Adapt: Replace npm with detected package manager. If repo has no typecheck or test script in package.json, omit those lines and tell the user.

5. Create .lintstagedrc

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

6. Create .prettierrc (if missing)

Only create if no Prettier config exists. Use these defaults:

{
  "useTabs": false,
  "tabWidth": 2,
  "printWidth": 80,
  "singleQuote": false,
  "trailingComma": "es5",
  "semi": true,
  "arrowParens": "always"
}

7. 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 verify it works

8. Commit

Stage all changed/created files and commit with message: Add pre-commit hooks (husky + lint-staged + prettier)

This will run through the new pre-commit hooks — a good smoke test that everything works.

Notes

  • Husky v9+ doesn't need shebangs in hook files
  • prettier --ignore-unknown skips files Prettier can't parse (images, etc.)
  • The pre-commit runs lint-staged first (fast, staged-only), then full typecheck and tests