setup-pre-commit

name	setup-pre-commit
description	Set up Husky pre-commit hooks with lint-staged running Prettier + ESLint, plus a full typecheck/lint/format/test gate, using the detected package manager. Use when user wants to add pre-commit hooks, set up Husky, configure lint-staged, add commit-time formatting/linting/typechecking/testing, or mentions "/setup-pre-commit".

Setup Pre-Commit Hooks

Steps

1. Detect package manager

Lockfile	Manager
bun.lock / bun.lockb	bun
pnpm-lock.yaml	pnpm
yarn.lock	yarn
package-lock.json	npm

Commands below assume bun/bunx. Swap for detected manager.

2. Install devDependencies (skip ones already present)

husky lint-staged prettier prettier-plugin-organize-imports @eslint/js eslint typescript-eslint jiti

Drop eslint + typescript-eslint + jiti if repo has no TypeScript.

3. Initialize Husky

bunx husky init

4. Add package.json scripts (merge, don't overwrite)

{
    "prepare": "husky",
    "typecheck": "bunx tsc --noEmit",
    "lint": "eslint src",
    "lint:fix": "eslint src --fix",
    "format": "prettier --write .",
    "format:check": "prettier --check .",
    "check": "bun run typecheck && bun run lint && bun run format:check && bun test"
}

Omit any script whose tool isn't installed.

5. Write .husky/pre-commit

bunx lint-staged
bun run check

Husky v9+ — no shebang. Skip the bun run check line for repos with slow test suites; let CI catch it.

6. Write .lintstagedrc

{
    "*.{ts,tsx,js,jsx,json,md,yml,yaml}": ["prettier --write"],
    "*.{ts,tsx,js,jsx}": ["eslint --fix"]
}

Drop the second entry when repo has no ESLint.

7. Write .prettierrc if missing

{
    "semi": true,
    "singleQuote": false,
    "tabWidth": 4,
    "trailingComma": "all",
    "printWidth": 100,
    "plugins": ["prettier-plugin-organize-imports"]
}

8. Write .prettierignore if missing

node_modules
dist
build
coverage
bun.lock
pnpm-lock.yaml
yarn.lock
package-lock.json
*.log
docs

9. Write eslint.config.ts if missing (TypeScript repos)

import js from "@eslint/js";
import tseslint from "typescript-eslint";

export default tseslint.config(
    { ignores: ["node_modules", "dist", "build", "coverage"] },
    js.configs.recommended,
    ...tseslint.configs.recommended,
    {
        languageOptions: { parserOptions: { projectService: true } },
        rules: {
            "no-empty": ["error", { allowEmptyCatch: true }],
            "no-control-regex": "off",
        },
    },
    {
        files: ["**/*.test.ts", "**/test-helpers.ts"],
        rules: { "@typescript-eslint/no-non-null-assertion": "off" },
    },
);

10. Verify + commit

bun run check
bunx lint-staged

Commit with chore: add pre-commit hooks (husky + lint-staged) — the commit itself exercises the hook.

Gotchas

Failure	Fix
check runs tests on every commit; slow repo feels painful	Drop bun run check from hook; keep only lint-staged. Run full check in CI.
Husky hook not executable	chmod +x .husky/pre-commit
prepare script missing from package.json	Re-run bunx husky init; it adds it
ESLint complains about projectService	Add a tsconfig.json with include: ["src/**/*"] — projectService needs one
Prettier reformats huge chunks of repo on first run	Run bun run format + commit separately BEFORE adding the hook so reformat noise is isolated
Lint-staged runs on binaries	File globs in .lintstagedrc scope to text extensions; don't use "*": "..."

Edge cases

Scenario	Handling
No TypeScript in repo	Skip eslint.config.ts, drop typecheck script, drop @typescript-eslint/* deps
No test script	Compose check as typecheck && lint && format:check; drop the && bun test
Prettier config already present	Keep existing config; only add missing scripts + husky wiring
Monorepo	Install deps at root; scripts + hooks belong at root; lint-staged runs against the whole staged set regardless of workspace
Repo has existing .husky/pre-commit	Read first; append missing lines rather than overwrite
User already uses Prettier v2	bunx husky init works on v9 Husky but prettier-plugin-organize-imports needs Prettier v3; tell the user before upgrading