Setup Pre-Commit Hooks

What This Sets Up

• Husky pre-commit hook
• lint-staged running Prettier on all staged files
• Prettier config (if missing)
• the typecheck script in the pre-commit hook

Tests don't run on commit. A full test run on every commit slows each commit by however long the suite takes, and CI runs it anyway as the check that blocks a merge.

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

Adapt: Replace npm with detected package manager. If repo has no typecheck script in package.json, omit that line and tell the user.

Then check that CI runs the test script on pull requests. If it doesn't, tell the user the tests run nowhere and offer to add a CI job, or to put npm run test in .husky/pre-push as a stopgap.

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 a full typecheck