Rebase vs Merge Comparison

Rebase vs Merge Comparison

Understanding when to use rebase versus merge is crucial for maintaining a clean and efficient Git history. This guide will help you make informed decisions about which operation to use in different scenarios.

What You’ll Learn

• Understanding rebase and merge
• When to use each operation
• Pros and cons
• Best practices
• Common scenarios

Implementation Steps

1. Basic Merge

   # Switch to main branch
   git checkout main
   
   # Merge feature branch
   git merge feature-branch
   
   # Verify merge
   git log --graph --oneline
   

   • Create merge commit
   • Preserve history
   • Handle conflicts
   • Verify changes

2. Basic Rebase

   # Switch to feature branch
   git checkout feature-branch
   
   # Rebase onto main
   git rebase main
   
   # Handle conflicts
   git add .
   git rebase --continue
   

   • Update branch
   • Linear history
   • Resolve conflicts
   • Push changes

3. Interactive Rebase

   # Start interactive rebase
   git rebase -i HEAD~3
   
   # Edit commits
   # Reorder commits
   # Squash commits
   # Drop commits
   

   • Clean history
   • Combine commits
   • Reorder changes
   • Remove commits

4. Merge Strategies

   # Fast-forward merge
   git merge --ff-only feature-branch
   
   # No-fast-forward merge
   git merge --no-ff feature-branch
   
   # Squash merge
   git merge --squash feature-branch
   

   • Choose strategy
   • Handle conflicts
   • Maintain history
   • Verify results

Best Practices

1. When to Merge

   • Public branches
   • Shared history
   • Complex features
   • Team collaboration

2. When to Rebase

   • Local branches
   • Clean history
   • Before sharing
   • Simple features

3. Conflict Resolution

   • Understand changes
   • Test thoroughly
   • Document decisions
   • Verify results

4. History Management

   • Keep it clean
   • Document decisions
   • Follow conventions
   • Regular cleanup

Common Use Cases

1. Feature Development

   # Start feature
   git checkout -b feature
   
   # Make changes
   git commit -m "Add feature"
   
   # Update with main
   git rebase main
   
   # Merge to main
   git checkout main
   git merge feature
   

2. Bug Fixes

   # Create fix branch
   git checkout -b fix-bug
   
   # Fix bug
   git commit -m "Fix bug"
   
   # Merge to main
   git checkout main
   git merge fix-bug
   

3. Long-Running Features

   # Update feature
   git checkout feature
   git rebase main
   
   # Handle conflicts
   git add .
   git rebase --continue
   
   # Push changes
   git push -f origin feature
   

4. Release Preparation

   # Update release branch
   git checkout release
   git merge main
   
   # Fix issues
   git commit -m "Fix release issues"
   
   # Merge to main
   git checkout main
   git merge release
   

Advanced Usage

1. Complex Rebasing

   # Interactive rebase
   git rebase -i HEAD~5
   
   # Edit specific commit
   git rebase -i HEAD~3
   # Change 'pick' to 'edit'
   # Make changes
   git commit --amend
   git rebase --continue
   

2. Merge Strategies

   # Octopus merge
   git merge branch1 branch2 branch3
   
   # Ours merge
   git merge -X ours feature
   
   # Theirs merge
   git merge -X theirs feature
   

3. History Cleanup

   # Clean up history
   git rebase -i HEAD~10
   
   # Drop commits
   # Squash commits
   # Reorder commits
   # Edit messages
   

4. Conflict Resolution

   # Use merge tool
   git mergetool
   
   # Abort operation
   git rebase --abort
   git merge --abort
   
   # Continue after fix
   git add .
   git rebase --continue
   

Common Issues and Solutions

1. Rebase Conflicts

   # Handle conflicts
   git add .
   git rebase --continue
   
   # Skip commit
   git rebase --skip
   
   # Abort rebase
   git rebase --abort
   

2. Merge Issues

   # Resolve conflicts
   git add .
   git commit -m "Resolve conflicts"
   
   # Abort merge
   git merge --abort
   
   # Force merge
   git merge -X theirs feature
   

3. History Problems

   # Fix history
   git rebase -i HEAD~5
   
   # Revert changes
   git reset --hard HEAD~1
   
   # Recover lost commits
   git reflog
   

Conclusion

Choose operations wisely. Remember to:

• Understand differences
• Consider context
• Follow practices
• Maintain history
• Test thoroughly

Next Steps

After mastering rebase and merge, consider:

• Learning Git workflows
• Exploring Git internals
• Understanding Git hooks
• Setting up automation