Setup Pre Commit

---
name: setup-pre-commit
description: "Set up Husky pre-commit hooks with lint-staged, Prettier, typecheck and tests. User-invoked only."
disable-model-invocation: true
license: MIT
---

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  Source: https://github.com/mattpocock/skills
  Pinned commit: c55ee46073ed923f86ce59a5eb3b6d895095d1b7
  Upstream path: skills/misc/setup-pre-commit/
  License: MIT (c) 2026 Matt Pocock -- full text in LICENSE next to this file
  Forge vendor note: frontmatter disable-model-invocation: true (it runs npm/npx installs and commits, so it is user-invoked only; upstream lacked the key), frontmatter license: MIT key and this provenance block added; agents/openai.yaml (Codex UI metadata, no function in Claude Code) not shipped; everything else verbatim.
  Reviewed for prompt-injection patterns, hidden/zero-width/bidi/control unicode, network use and deletes by build-boss, 2026-09-24 -- clean; every upstream file sha256-verified against the pinned-commit manifest before copying.
-->

# 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

```bash
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`

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

### 6. Create `.prettierrc` (if missing)

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

```json
{
  "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