Git Hooks and Automation

Learn how to use Git hooks to automate your development workflows.

Git Hooks Basics

Configuration

# Enable hooks
git config core.hooksPath .git/hooks

# Create a pre-commit hook
touch .git/hooks/pre-commit
chmod +x .git/hooks/pre-commit

Common Hooks

# pre-commit
#!/bin/sh
# Runs before each commit
echo "Vérification du code..."

# post-commit
#!/bin/sh
# Runs after each commit
echo "Notification envoyée..."

# pre-push
#!/bin/sh
# Runs before each push
echo "Tests en cours..."

# post-merge
#!/bin/sh
# Runs after each merge
echo "Mise à jour des dépendances..."

Practical Examples

Code Checks

# pre-commit
#!/bin/sh

# Check formatting
echo "Vérification du formatage..."
npm run lint

# Run tests
echo "Exécution des tests..."
npm test

# Check types
echo "Vérification des types..."
npm run type-check

Message Validation

# commit-msg
#!/bin/sh

# Check the message format
commit_msg=$(cat "$1")
if ! echo "$commit_msg" | grep -qE "^(feat|fix|docs|style|refactor|test|chore)(\(.+\))?: .+"; then
    echo "Format de message invalide"
    echo "Utilisez: type(scope): description"
    exit 1
fi

Automatic Deployment

# post-push
#!/bin/sh

# Deploy to staging
if [ "$(git rev-parse --abbrev-ref HEAD)" = "develop" ]; then
    echo "Déploiement en staging..."
    npm run deploy:staging
fi

# Deploy to production
if [ "$(git rev-parse --abbrev-ref HEAD)" = "main" ]; then
    echo "Déploiement en production..."
    npm run deploy:prod
fi

Husky for Node.js

Installation

# Install Husky
npm install husky --save-dev

# Initialize Husky
npx husky install

# Add a hook
npx husky add .husky/pre-commit "npm test"

Configuration

// package.json
{
  "scripts": {
    "prepare": "husky install"
  },
  "husky": {
    "hooks": {
      "pre-commit": "npm test",
      "commit-msg": "commitlint -E HUSKY_GIT_PARAMS"
    }
  }
}

Git Hooks with Python

Hook Example

#!/usr/bin/env python3
# pre-commit

import sys
import subprocess

def run_tests():
    try:
        subprocess.run(['pytest'], check=True)
    except subprocess.CalledProcessError:
        print("Les tests ont échoué")
        sys.exit(1)

def check_formatting():
    try:
        subprocess.run(['black', '--check', '.'], check=True)
    except subprocess.CalledProcessError:
        print("Le formatage est incorrect")
        sys.exit(1)

if __name__ == '__main__':
    run_tests()
    check_formatting()

Continuous Integration

GitHub Actions

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Install dependencies
      run: npm install
    - name: Run tests
      run: npm test
    - name: Check formatting
      run: npm run lint

GitLab CI

# .gitlab-ci.yml
stages:
  - test
  - deploy

test:
  stage: test
  script:
    - npm install
    - npm test
    - npm run lint

deploy:
  stage: deploy
  script:
    - npm run deploy
  only:
    - main

Best Practices

1. Security

   • Check dependencies
   • Scan the code
   • Validate secrets
   • Protect branches

2. Performance

   • Lightweight hooks
   • Fast tests
   • Result caching
   • Parallelization

3. Maintenance

   • Clear documentation
   • Hook testing
   • Error handling
   • Detailed logs

Conclusion

Key takeaways:

• Process automation
• Code validation
• Automatic deployment
• Continuous integration

Recommendations:

• Choose the right hooks
• Automate your tests
• Secure your workflows
• Follow best practices
• Keep learning Git