Git
How Git Rebase Works?
Git is an indispensable tool for version control, enabling developers to collaborate efficiently. Among its many commands, git rebase stands out as a powerful yet often misunderstood tool.
By learning how to use it properly, you can clean up your commit history, resolve conflicts effectively, and streamline your workflows.
In this blog, we’ll explore what Git rebase is, how it works, and when to use it.
What is Git Rebase?
Git rebase is a command that moves or replays commits from one branch onto another. Instead of merging two branches, which adds a merge commit to the history, rebasing rewrites the commit history to make it appear as though your changes were made sequentially after the target branch’s commits.
Why Use Git Rebase?
- Cleaner Commit History: It eliminates unnecessary merge commits, resulting in a linear history.
- Improved Clarity: A rebased history makes it easier to understand the progression of changes.
- Enhanced Collaboration: It helps reduce potential merge conflicts when multiple developers are working on a shared codebase.
How Git Rebase Works
1. The Basic Command
To rebase your current branch onto another branch:
git rebase <target-branch>
For example, if you’re on feature-branch and want to rebase it onto main:
git checkout feature-branch
git rebase main
This moves the commits from feature-branch to the top of main, replaying them as though they were made after the latest commit on main.
2. Rebase Workflow
Consider this scenario:
mainbranch commits: A → B → Cfeature-branchcommits: D → E → F
After running git rebase main on feature-branch, the commit history becomes:
main: A → B → C
feature-branch: A → B → C → D → E → F
The commits D, E, and F are replayed on top of main.
3. Resolving Conflicts During Rebase
Rebasing may pause if conflicts arise. When this happens:
- Git will stop and notify you of the conflicting files:
CONFLICT (content): Merge conflict in <file> - Open the conflicting files and resolve the issues.
- Stage the resolved files:
git add <file> - Continue the rebase:
git rebase --continue - If you need to stop the rebase entirely:
git rebase --abort
Types of Git Rebase
1. Interactive Rebase
An interactive rebase (git rebase -i) gives you control over each commit, allowing you to edit, reorder, squash, or drop commits. To start:
git rebase -i <target-branch>
Git will open an editor listing the commits to be rebased. You can:
- Pick: Keep the commit as is.
- Edit: Modify the commit message or contents.
- Squash: Combine multiple commits into one.
- Drop: Remove a commit entirely.
2. Rebasing with --onto
The --onto flag lets you rebase commits onto a different branch or specific commit. For example:
git rebase --onto new-base old-base feature-branch
This replays commits from feature-branch after old-base onto new-base.
Rebase vs Merge
| Rebase | Merge |
|---|---|
| Rewrites commit history. | Preserves the original history. |
| Creates a linear history. | Adds a merge commit. |
| Useful for cleaner history. | Useful for tracking branch merges. |
When to Use Git Rebase
- Updating a Feature Branch: Use rebase to keep your feature branch up-to-date with the latest changes from the main branch.
- Squashing Commits: Use interactive rebase to combine multiple commits into one for a cleaner history.
- Before Merging: Rebase your feature branch to ensure a linear history before merging it into the main branch.
Caution: Avoid rebasing shared branches, as it rewrites commit history and can cause issues for collaborators.
Best Practices for Git Rebase
- Use Rebase for Local Branches: Avoid rebasing branches that others are working on to prevent conflicts.
- Back Up Your Branch: Create a backup branch before rebasing in case something goes wrong.
- Be Mindful of Public Repositories: Do not rebase public or shared branches.
Conclusion
Git rebase is a powerful tool for managing commit history and keeping your branches clean and organized.
By mastering rebase, you can improve collaboration, simplify debugging, and maintain a professional codebase. Use it wisely and pair it with good Git practices to maximize its benefits.
