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

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 --no-install 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 --no-install 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 --no-install lint-staged to verify it works (only run the locally installed copy, never fetch one from the registry)

8. Commit

Stage only the files this skill created or changed (package.json, the lockfile, .husky/pre-commit, .lintstagedrc, and .prettierrc if created), never unrelated or untracked 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