Lefthook Setup Guide

Why Lefthook?

Lefthook run automated checks before code commit. Catch bugs, format issues, lint errors before production.

• Frontend ESLint validation
• Backend Go tests
• Backend format checks

Commit fail if checks fail.

Prerequisites

Need:

• Node.js 18+
• npm
• Go 1.21+

Check versions:

node -v
npm -v
go version

Install Lefthook

From project root:

npm install --save-dev lefthook
npx lefthook install

Output show sync hooks: ✔️.

Verify Installation

npx lefthook run pre-commit

Execute configured checks.

Normal Development Flow

Before commit:

git add .
git commit -m "your message"

Lefthook run automatically. If check fail, commit rejected. Fix issue, commit again.

Troubleshooting

Lefthook not running:

npx lefthook install

Skip hooks temporarily (emergency only):

git commit --no-verify -m "message"

Configuration

Config file: lefthook.yml.

Add new checks example:

pre-commit:
  jobs:
    backend-test:
      root: backend/
      run: go test ./...
    frontend-lint:
      root: customer/
      run: npm run lint

Run npx lefthook install after change.

Team Rule

All developers must install Lefthook before contribute. Do not commit code with failing tests, lint errors, broken builds, format issues.

Commit package.json, package-lock.json, lefthook.yml to Git. Do NOT commit .git/hooks. Other devs clone and run npm install then npx lefthook install.

Written by A.M. Rinas