When working with Git, two common strategies for integrating changes from different branches are merging and rebasing. Both techniques serve the purpose of combining code from multiple branches, but they do so in different ways. This article will help you understand the differences between merging and rebasing, and guide you on when to use each strategy.
Git merge
Merging is a way to combine the changes from one branch into another. When you merge a branch, Git creates a new commit called a merge commit that has two parent commits: one from the current branch and one from the branch being merged.
git checkout feature
git merge main
Or, you can write
git merge feature mainHow does it work?
It basically, creates a new "feature commit", safeguarding the history of both the branches and giving it a structure like this:-
Features of Merging
- Integrating feature branches into the main development branch.
- Resolving conflicts between branches.
- Preserving the commit history of both branches.
Advantages of Merging
- Preserves History: Merging preserves the complete history of changes, making it easy to trace back through the commit history.
- Contextual Clarity: The merge commit provides a clear indication that branches have been combined, offering context for future reference.
Git Rebase
Rebasing is a process of moving or combining a sequence of commits to a new base commit. It allows you to take the changes from one branch and reapply them on top of another branch.
git rebase mainHow does it work?
Git rebase actually rebases the feature branch and merges it with the main branch. In simple words, it moves the entire feature branch to the tip of the main branch. The pictorial representation looks a bit like this:-
Features
- Maintaining a cleaner and more linear commit history.
- Facilitating easier code review and debugging.
- Avoiding unnecessary merge commits.
Advantages of Rebasing
- Cleaner History: Rebasing creates a linear history, which can make the commit history easier to read and understand.
- Bisecting Simplicity: A linear history simplifies the use of tools like
git bisectfor debugging.
Why is Rebase Commonly Used in Pull Requests (PRs)?
- In many development teams, developers create feature branches and raise Pull Requests (PRs) to merge their changes into the
mainbranch. - While the PR is open, the
mainbranch may continue receiving new commits from other developers. This can make the feature branch outdated. - Rebasing helps update the feature branch with the latest changes from the
mainbranch before merging the PR.
Example
- Suppose you created a feature branch
git checkout feature- Meanwhile, new commits are added to the
mainbranch. - Before updating or merging the PR, you can rebase your branch
git fetch origingit rebase origin/main
- This moves your feature branch commits on top of the latest
mainbranch commits.
Difference Between Merging and Rebasing
| Feature | Merge | Rebase |
|---|---|---|
| Commit History | Preserves the complete history of both branches | Rewrites commit history to create a cleaner flow |
| History Structure | Creates a non-linear branch structure | Creates a clean and linear commit structure |
| Ease of Use | Easier and safer for beginners | Slightly more complex and advanced |
| Merge Commits | Generates an additional merge commit | Avoids unnecessary merge commits |
| Best Suitable For | Better for large teams and shared branches | Better for maintaining a clean project history |
| Command Example | git merge feature | git rebase main |