Git
How to Rebase in Git?
Rebasing in Git is a powerful way to streamline and clean up your project’s commit history. It’s an alternative to merging and is particularly useful in collaborative workflows where an organized history improves readability and collaboration.
This blog will explain what rebasing is, why you might use it, and how to safely perform a rebase in Git.
What Is Git Rebase?
Rebasing is the process of moving or reapplying commits from one branch onto another. Unlike merging, which creates a new “merge commit” that combines the histories of two branches, rebasing integrates changes by rewriting commit history as if the changes were applied sequentially.
Key Differences Between Merge and Rebase
| Feature | Merge | Rebase |
|---|---|---|
| History | Preserves the original history with a merge commit. | Rewrites history to create a linear timeline. |
| Conflict Resolution | Handled during the merge. | Handled interactively during the rebase. |
| Commit History | Contains branches and merge commits. | Creates a clean, linear commit history. |
Why Use Git Rebase?
- Clean Commit History: Rebasing creates a linear history, making it easier to understand.
- Avoid Merge Commits: No extra merge commits clutter the history.
- Collaborative Workflows: Ideal for keeping feature branches up-to-date with the main branch.
How to Perform a Git Rebase
1. Rebase a Branch onto Another
The most common use case is rebasing a feature branch onto the main branch.
Step 1: Switch to the Branch You Want to Rebase
First, ensure you’re on the branch you want to rebase. For example, if you’re rebasing feature onto main:
git checkout feature
Step 2: Rebase onto the Target Branch
Run the rebase command:
git rebase main
This applies your commits from feature onto the latest state of main.
Step 3: Resolve Any Conflicts
If there are conflicts, Git will pause the rebase and prompt you to resolve them.
- Identify the conflicting files:
git status - Edit the files to resolve the conflicts.
- Mark conflicts as resolved:
git add <file> - Continue the rebase:
git rebase --continue
Step 4: Verify the Result
Once the rebase completes, verify your branch’s history:
git log --oneline
2. Interactive Rebase
Interactive rebasing gives you control over how commits are handled, allowing you to squash, edit, or reorder commits.
Step 1: Start the Interactive Rebase
To rebase the last few commits interactively, run:
git rebase -i HEAD~<number_of_commits>
For example, to rebase the last three commits:
git rebase -i HEAD~3
Step 2: Edit the Commit List
Git will open an editor displaying your commits. You can modify the action for each commit by replacing the keyword at the beginning of the line (e.g., pick, squash, edit).
Example Commit List:
pick a1b2c3 Add login functionality
pick d4e5f6 Fix login bug
pick g7h8i9 Update README
- Change
picktosquashto merge commits. - Change
picktoeditto modify a commit message.
Step 3: Complete the Rebase
Save the changes, and Git will process the rebase based on your instructions.
3. Abort a Rebase
If you encounter issues or decide not to continue the rebase, you can abort it:
git rebase --abort
This restores your branch to the state it was in before the rebase started.
Best Practices for Rebasing
- Avoid Rebasing Public Branches: Rewriting history on shared branches can cause confusion and conflicts for other collaborators.
- Rebase Before Pushing: Only rebase local branches that haven’t been pushed to a remote repository.
- Use Interactive Rebase for Cleanup: Squash, reorder, or amend commits before sharing your branch with others.
- Pull with Rebase: When integrating changes from a remote branch, use:
git pull --rebaseThis applies your local commits on top of the updated remote branch.
Common Scenarios for Using Git Rebase
1. Keep a Feature Branch Updated
If you’re working on a feature branch while the main branch is being updated, you can rebase your branch to include the latest changes:
git checkout feature
git rebase main
2. Clean Up Commit History
Before merging a feature branch into the main branch, use interactive rebase to combine related commits and ensure a concise history:
git rebase -i HEAD~<number_of_commits>
Conclusion
Git rebase is a powerful tool for maintaining a clean and linear project history. While it requires careful handling, especially in collaborative settings, mastering rebasing can significantly improve your workflow. Use it wisely to enhance clarity and efficiency in your Git repository.
By following the steps and best practices outlined in this guide, you can confidently use Git rebase to streamline your development process.