When do you use Git rebase instead of Git merge?

 

Git rebase and Git merge are two different ways to integrate changes from one branch into another. The choice between them depends on your workflow and the desired commit history. Here's when you might use Git rebase instead of Git merge, illustrated with an example:

Git Merge:

Let's say you have a feature branch feature-branch and a main branch main. You've completed your work on the feature branch and want to integrate it into the main branch. You can do this with a merge:

1. Checkout the main branch: git checkout main

2. Merge the feature branch into main: git merge feature-branch

   This creates a new merge commit on the main branch that ties together the histories of both branches. The commit history will look something like this:

   scss

2. o---o---o---M (main)
            \
             o---o (feature-branch)
   

Git Rebase:

Now, let's see when you might use Git rebase instead. Suppose you have the same feature-branch and main branches again:

1. Checkout the feature branch: git checkout feature-branch

2. Rebase the feature branch onto the main branch: git rebase main

   This replays your changes from the feature branch on top of the main branch, effectively rewriting the commit history. The commit history will look something like this:

   scss

2. o---o---o (main)
                \
                 o---o---o (feature-branch)
   

When to use Git rebase instead of Git merge:

1. Linear History: If you prefer a linear commit history with a clear sequence of commits, rebasing is a better option. It eliminates the extra merge commits that can clutter the history.

2. Clean History: Rebase keeps the commit history clean and easier to read, as it integrates the changes one by one instead of creating a merge commit with multiple changes.

3. Squashing Commits: You can also use an interactive rebase (git rebase -i) to squash, edit, or reorder commits before integrating them into the main branch. This allows you to present a cleaner and more coherent set of changes.

However, there are some caveats to be aware of:

• Shared Branches: If you're working on a branch that others are using, be cautious with rebasing, as it rewrites history. It's generally safe for your local feature branches but not for branches that others depend on.

• Conflicts: Rebasing can lead to conflicts when replaying changes. You must resolve these conflicts during the rebase process.

In summary, use Git rebase when you want a clean, linear commit history, and you're working on your own or a short-lived feature branch. Use Git merge when you want to preserve the branch's history or when working on shared branches with others.