Setup Pre Commit

Pre-Commit Hook Setup

What gets configured

• Husky pre-commit hook
• lint-staged running Prettier on all staged files
• Prettier configuration (if not present)
• typecheck and test scripts in the pre-commit hook

Steps

1. Detect the package manager

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

2. Install dependencies

Install as devDependencies:

husky lint-staged prettier

3. Initialize Husky

npx husky init

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

4. Create .husky/pre-commit

Write this file (Husky v9+ does not need a shebang):

npx lint-staged
npm run typecheck
npm run test

Adapt: replace npm with the detected package manager. If package.json has no typecheck or test script, drop the corresponding line and inform the user.

5. Create .lintstagedrc

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

6. Create .prettierrc (if missing)

Create only if no Prettier configuration exists yet. 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
• The prepare script in package.json equals "husky"
• A prettier configuration exists
• Run npx lint-staged to confirm everything works

8. Commit

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

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

Notes

• Husky v9+ does not require a shebang in hook files
• prettier --ignore-unknown skips files Prettier cannot parse (images, etc.)
• The pre-commit hook first runs lint-staged (fast, only staged files), then full typecheck and tests