# Format
<type>(<scope>): <subject>

<body>

<footer>

# ✅ Good commit messages
feat(auth): add password reset functionality

fix(cart): resolve quantity update race condition

docs(readme): add installation instructions

refactor(api): extract validation into middleware

test(user): add unit tests for registration

chore(deps): update dependencies to latest versions

# With body and footer
feat(orders): implement order cancellation

Add ability for users to cancel pending orders within 24 hours.
Cancelled orders trigger refund process automatically.

Closes #123
BREAKING CHANGE: Order status enum now includes 'cancelled'

# ❌ Bad commit messages
fix bug
update
WIP
asdfasdf
changes
misc fixes

# ✅ Good branch names
feature/user-authentication
feature/JIRA-123-password-reset
fix/cart-total-calculation
fix/issue-456-login-redirect
hotfix/security-patch
docs/api-documentation
refactor/database-queries
chore/update-dependencies

# ❌ Bad branch names
new-feature
john-branch
test
fix
temp
asdf

# Main branches
main          # Production-ready code
develop       # Integration branch (optional)

# Supporting branches
feature/*     # New features
fix/*         # Bug fixes
hotfix/*      # Production hotfixes
release/*     # Release preparation

# Workflow
git checkout main
git pull origin main
git checkout -b feature/user-profile

# Work on feature...
git add .
git commit -m "feat(profile): add profile page"

# Keep branch updated
git fetch origin
git rebase origin/main

# Push and create PR
git push -u origin feature/user-profile

# ❌ One commit doing multiple things
git commit -m "Add login, fix header, update deps"

# ✅ Separate commits for each change
git commit -m "feat(auth): add login page"
git commit -m "fix(header): correct navigation alignment"
git commit -m "chore(deps): update React to v18.2"

# ✅ Small, frequent commits
git commit -m "feat(cart): add product to cart"
git commit -m "feat(cart): display cart item count"
git commit -m "feat(cart): implement remove item"
git commit -m "test(cart): add unit tests"

# ❌ One massive commit
git commit -m "feat: implement entire shopping cart"

# Format (like commit)
<type>(<scope>): <description>

# ✅ Good PR titles
feat(auth): implement OAuth2 login
fix(checkout): resolve payment processing error
docs(api): add endpoint documentation

# ❌ Bad PR titles
Update
Fix stuff
WIP

## Summary
Brief description of what this PR does.

## Changes
- Added user authentication endpoints
- Implemented JWT token generation
- Added password hashing with bcrypt

## Testing
- [ ] Unit tests pass
- [ ] Integration tests pass
- [ ] Manual testing completed

## Screenshots (if UI changes)
[Add screenshots here]

## Related Issues
Closes #123
Related to #456

## Checklist
- [ ] Code follows project conventions
- [ ] Self-review completed
- [ ] Tests added/updated
- [ ] Documentation updated

# ✅ Focused PRs
PR #1: Add user model and migrations
PR #2: Implement user registration endpoint
PR #3: Add email verification
PR #4: Implement login/logout

# ❌ Large unfocused PR
PR #1: Add entire user authentication system
       (2000+ lines, 50+ files)

# ✅ Rebase for feature branches (clean history)
git checkout feature/my-feature
git fetch origin
git rebase origin/main
# Resolve any conflicts
git push --force-with-lease  # Only your branch!

# ✅ Merge for integrating to main (preserve context)
git checkout main
git merge --no-ff feature/my-feature
# Creates merge commit, preserves branch history

# ❌ Never force push to shared branches
git push --force origin main  # NEVER DO THIS

# Before pushing, clean up commits
git rebase -i HEAD~5

# In editor:
pick abc123 feat: add login page
squash def456 fix typo
squash ghi789 more fixes
pick jkl012 feat: add logout

# Result: clean history with meaningful commits

# During rebase
git rebase origin/main
# CONFLICT in file.ts

# 1. Open conflicted files
# 2. Resolve conflicts (remove markers)
# 3. Stage resolved files
git add file.ts

# 4. Continue rebase
git rebase --continue

# Or abort if needed
git rebase --abort

# .husky/pre-commit
#!/bin/sh
npm run lint
npm run test:unit

# .husky/commit-msg
#!/bin/sh
npx commitlint --edit $1

# commitlint.config.js
module.exports = {
  extends: ['@commitlint/config-conventional'],
};

# Semantic versioning tags
git tag -a v1.0.0 -m "Release version 1.0.0"
git push origin v1.0.0

# List tags
git tag -l "v1.*"

# Tag format
v1.0.0    # Major.Minor.Patch
v1.0.0-beta.1  # Pre-release
v1.0.0-rc.1    # Release candidate

# Dependencies
node_modules/
vendor/

# Build outputs
dist/
build/
.next/

# Environment files
.env
.env.local
.env.*.local

# IDE
.idea/
.vscode/
*.swp

# OS files
.DS_Store
Thumbs.db

# Logs
*.log
logs/

# Test coverage
coverage/

# Cache
.cache/
*.cache

# View commit history
git log --oneline --graph --all

# See what changed
git diff --staged
git diff HEAD~1

# Undo last commit (keep changes)
git reset --soft HEAD~1

# Discard local changes
git checkout -- file.ts
git restore file.ts  # Git 2.23+

# Stash changes
git stash
git stash pop
git stash list

# Cherry-pick commit
git cherry-pick abc123

# Find who changed a line
git blame file.ts

# Search commits
git log --grep="fix"
git log -S "functionName"

[category] Description of issue or suggestion

[commit] Use imperative mood: "Add feature" not "Added feature"
[branch] Branch name 'test' should follow pattern: feature/description
[pr] PR is too large (50+ files), consider splitting

rules/commit-conventional-format.md
rules/branch-naming-convention.md
rules/pr-small-focused.md

// commitlint.config.js
module.exports = {
  extends: ['@commitlint/config-conventional'],
  rules: {
    'type-enum': [
      2,
      'always',
      ['feat', 'fix', 'docs', 'style', 'refactor', 'perf', 'test', 'chore', 'ci', 'build', 'revert']
    ],
    'subject-max-length': [2, 'always', 72],
    'body-max-line-length': [2, 'always', 100]
  }
};

# .husky/commit-msg
#!/bin/sh
npx commitlint --edit $1

# .husky/pre-commit
#!/bin/sh
npm run lint
npm test

# .github/PULL_REQUEST_TEMPLATE.md
## Summary
Brief description of changes

## Changes
- List key changes
- One per line

## Testing
- [ ] Unit tests pass
- [ ] Integration tests pass
- [ ] Manual testing completed

## Related
Closes #issue-number