Git Hooks & Automation

# === Explore existing hook samples ===
ls .git/hooks/
# pre-commit.sample, pre-push.sample, commit-msg.sample ...

# === Write a simple pre-commit hook ===
cat > .git/hooks/pre-commit << 'EOF'
#!/bin/bash
echo "🔍 Running pre-commit checks..."

# Check for debug statements
if git diff --cached --name-only | xargs grep -l "console.log\|debugger" 2>/dev/null; then
  echo "❌ BLOCKED: console.log or debugger found in staged files!"
  echo "   Remove debug statements before committing."
  exit 1
fi

echo "✅ Pre-commit checks passed!"
exit 0
EOF
chmod +x .git/hooks/pre-commit

# === Write a commit-msg hook ===
cat > .git/hooks/commit-msg << 'EOF'
#!/bin/bash
MSG=$(cat "$1")
PATTERN="^(feat|fix|chore|docs|refactor|test|style|ci)(\(.+\))?: .{1,72}$"

if ! echo "$MSG" | grep -qE "$PATTERN"; then
  echo "❌ BLOCKED: Invalid commit message format!"
  echo "   Use: feat: description (max 72 chars)"
  echo "   Types: feat|fix|chore|docs|refactor|test|style|ci"
  echo "   Your message: $MSG"
  exit 1
fi
echo "✅ Commit message format valid!"
exit 0
EOF
chmod +x .git/hooks/commit-msg

# === Test it ===
echo "console.log('debug')" > test.js
git add test.js
git commit -m "bad message"
# → ❌ BLOCKED: console.log found

# === Setup: requires package.json ===
cd my-devops-app
npm init -y                         # Init if not done

# === Install Husky ===
npm install --save-dev husky

# === Initialize Husky (creates .husky/ dir) ===
npx husky init
# Creates: .husky/pre-commit (sample)
# Adds:   "prepare": "husky" to package.json scripts
# .husky/ is committed to git — team gets hooks on npm install

# === View what was created ===
ls .husky/
cat .husky/pre-commit
cat package.json | grep prepare

# === How it works on clone ===
# When a teammate runs: git clone → npm install
# npm runs the "prepare" script → husky installs
# hooks are set up automatically — no manual steps

# === Add a pre-commit hook ===
echo "npx lint-staged" > .husky/pre-commit

# === Add a pre-push hook (run tests) ===
echo "npm test" > .husky/pre-push

# === Add commit-msg hook (commitlint) ===
echo 'npx --no-install commitlint --edit "$1"' > .husky/commit-msg

# === Commit .husky to share with team ===
git add .husky package.json
git commit -m "chore: add husky git hooks"

# === Install commitlint ===
npm install --save-dev @commitlint/cli @commitlint/config-conventional

# === Create config (extend conventional preset) ===
cat > commitlint.config.js << 'EOF'
module.exports = {
  extends: ['@commitlint/config-conventional'],

  rules: {
    'type-enum': [2, 'always', [
      'feat', 'fix', 'chore', 'docs',
      'refactor', 'test', 'style', 'ci', 'perf'
    ]],
    'subject-max-length': [2, 'always', 72],
    'subject-case':       [2, 'always', 'lower-case'],
    'subject-empty':      [2, 'never'],
    'type-empty':         [2, 'never'],
    'scope-case':         [2, 'always', 'lower-case'],
  }
};
EOF

# === Wire to Husky commit-msg hook ===
echo 'npx --no-install commitlint --edit "$1"' > .husky/commit-msg

# === Test FAILING commit ===
git commit -m "bad commit message"
# ✖   subject may not be empty [subject-empty]
# ✖   type may not be empty [type-empty]
# ✖   found 2 problems, 0 warnings

git commit -m "fixed the bug"
# ✖   type may not be empty [type-empty]

# === Test PASSING commit ===
git commit -m "fix: resolve null pointer in login handler"
# ✔   found 0 problems, 0 warnings

{
  "name": "my-devops-app",
  "version": "1.0.0",
  "scripts": {
    "prepare": "husky",
    "lint":    "eslint src/",
    "format":  "prettier --write .",
    "test":    "jest"
  },
  "devDependencies": {
    "husky":             "^9.0.0",
    "lint-staged":       "^15.0.0",
    "prettier":          "^3.0.0",
    "eslint":            "^8.0.0",
    "@commitlint/cli":   "^18.0.0",
    "@commitlint/config-conventional": "^18.0.0"
  },
  "lint-staged": {
    "*.{js,ts}": ["eslint --fix", "prettier --write"],
    "*.{json,md,yml}": ["prettier --write"]
  }
}

#!/bin/bash
# .husky/pre-push — runs before git push
# Good place for: tests, build check, security scan

set -e   # Exit immediately if any command fails

echo "🧪 Running tests before push..."
npm test

echo "🏗  Verifying build..."
npm run build

echo "🛡  Checking for secrets in staged files..."
if git diff origin/main...HEAD | grep -E "(password|secret|api_key|token)\s*=" 2>/dev/null; then
  echo "❌ BLOCKED: Potential secret found in commit!"
  exit 1
fi

echo "✅ All pre-push checks passed!"

cd my-devops-app

# === 1. Init (skip if package.json exists) ===
npm init -y

# === 2. Install all tools ===
npm install --save-dev \
  husky \
  lint-staged \
  prettier \
  eslint \
  @commitlint/cli \
  @commitlint/config-conventional

# === 3. Initialize Husky ===
npx husky init
cat package.json | grep prepare  # Verify "prepare":"husky"
ls .husky/                        # Should see pre-commit file

# === 4. Pre-commit hook → lint-staged ===
echo "npx lint-staged" > .husky/pre-commit

# === 5. lint-staged config ===
cat > .lintstagedrc.json << 'EOF'
{
  "*.{js,ts}": ["eslint --fix", "prettier --write"],
  "*.{json,md,yml}": ["prettier --write"]
}
EOF

# === 6. ESLint config ===
cat > .eslintrc.json << 'EOF'
{
  "env": { "node": true, "es2021": true },
  "extends": "eslint:recommended",
  "rules": { "no-console": "warn", "no-debugger": "error" }
}
EOF

# === 7. commitlint config ===
cat > commitlint.config.js << 'EOF'
module.exports = {
  extends: ['@commitlint/config-conventional']
};
EOF

# === 8. commit-msg hook ===
echo 'npx --no-install commitlint --edit "$1"' > .husky/commit-msg

# Lefthook: works for ANY language (not just Node.js)
# Single YAML file instead of multiple .husky/ scripts

pre-commit:
  parallel: true        # Run checks in parallel (faster!)
  commands:
    lint:
      glob: "*.{js,ts}"
      run: npx eslint --fix {staged_files}
    format:
      glob: "*.{js,ts,json,md}"
      run: npx prettier --write {staged_files}
    python-lint:
      glob: "*.py"
      run: flake8 {staged_files}
    shell-check:
      glob: "*.sh"
      run: shellcheck {staged_files}

commit-msg:
  commands:
    commitlint:
      run: npx commitlint --edit {1}

pre-push:
  commands:
    tests:
      run: npm test
    type-check:
      run: npx tsc --noEmit