Hello there.
In this article, I won’t even try to convince you to use one thing over another.
There are two common ways to combine changes from different branches in git: merge and rebase. merge creates a new commit (with two parents) where it combines all changes, whereas rebase rewrites a history of commits and puts one set of commits on top of another set of commits from the base branch.
Usually, people prefer merge (at least from my experience) over rebase and I can easily understand why. If you want to merge something, well you need to use the merge command, easy. This command works pretty much as expected and usually doesn’t produce any issues. But what is rebase? How does it work? If you are not so proficient with git, there is always a fear of breaking something or losing your changes.
But first of all, let’s look a bit closer at the details of how these commands work and what commit tree they produce.
merge
* a78d34a3 Merge feature-1
|\
| * 33d76e0a Fix bug
| |
| * 32d76e0a Implement feature-1
|/
* 83e461ac Base commit
It’s a sample formatted output of git log with 4 commits. The one on the bottom is “base commit”, then we can see two other commits in the separate branch to implement a feature and to fix a bug and then the merge commit. I think everyone is familiar with this structure and at first glance, it looks pretty much fine. Let’s look at rebase.
rebase
* a78d34a3 Implement feature-1
|
* 83e461ac Base commit
A similar output but it has only two commits. The first one is “base commit” and the last one is the feature commit, nothing else, no merge commits, linear history.
My preferences
Actually, it is one of the main reasons why I prefer rebase - linear commit history. Especially, it is true for a lot of consecutive merge commits. Instead of creating a “christmas tree” in the git history, you can create a linear structure as if they were committed directly to the base branch. This advantage can be combined with interactive rebase - git rebase -i where you can manually “rewrite” the history of your commits, like change order, change message, combine (squash) or split commits, etc. It’s kind of advanced feature but also it provides you full control over commit history.