Mastering Git Interactive Rebase: A Step-by-Step Guide

Git is one of the most popular version control systems used by software engineers today. It helps track changes in code and collaborate with others on the same project. However, with great power comes great responsibility. As a software engineer, you need to be comfortable with using Git to keep your code organized and up-to-date. In this article, I’ll dive into Git Interactive Rebase and how it can help streamline your workflow.

What is Git Interactive Rebase?

Git Interactive Rebase is a powerful feature in Git that allows you to edit, reorder, and squash multiple commits into a single commit. It’s a great way to clean up your commit history, making it easier to understand and maintain. The key word here is “interactive”, which means that you have control over the rebasing process and can decide which changes to apply and which to ignore.

Why should you care about Git Interactive Rebase?

It’s important to have a clean and organized commit history. This makes it easier to track changes and collaborate with others on the same project. Git Interactive Rebase allows you to rewrite history in a way that makes sense, helping you to avoid merge conflicts, clean up messy commits, and even fix mistakes you’ve made in the past. In short, Git Interactive Rebase helps you maintain a cleaner, more organized codebase.

Step-by-Step Guide to Git Interactive Rebase

Here’s a step-by-step guide to using Git Interactive Rebase:

1. Preparation Before you start an interactive rebase, it’s important to make sure your current branch is in a good state. Check the status of your branch to make sure there are no uncommitted changes, and then create a backup branch in case something goes wrong during the rebase.
2. Initiating an interactive rebase To start an interactive rebase, use the following command in your terminal:

$ git rebase -i HEAD~n

where n is the number of commits you want to rebase. This will open a text editor, showing a list of the latest n commits, along with some instructions on how to perform the rebase.

3. Editing commit history The text editor shows a list of all the commits you want to rebase, along with a set of commands that you can use to manipulate the commit history. To squash multiple commits into one, replace the word “pick” with “squash” for all but the first commit you want to keep. To reorder commits, simply change their order in the list.
4. Resolving conflicts If there are any conflicts during the rebase, Git will stop and ask you to resolve them. This can happen if you’ve made changes to the same lines of code in different commits. To resolve the conflict, edit the file to include the changes you want, then use git add to stage the file and continue the rebase with git rebase --continue.
5. Finishing the rebase Once you’ve resolved all conflicts and edited the commit history, the rebase will be finished. To see the new, updated commit history, use the following command:

$ git log

Common Use Cases for Git Interactive Rebase

Here are a few common use cases for Git Interactive Rebase:

1. Squashing commits If you’ve made a bunch of small, unrelated changes in multiple commits, you can use Git Interactive Rebase to squash them into a single commit. This makes your commit history easier to understand and reduces clutter in your codebase.
2. Rearranging commits Sometimes, you might want to rearrange the order of your commits to better reflect the changes you made. With Git Interactive Rebase, you can easily rearrange the order of your commits to better reflect the evolution of your code.
3. Editing commit messages If you’ve made a mistake in a commit message or want to make it more descriptive, you can use Git Interactive Rebase to edit it. This makes it easier for others to understand the changes you’ve made and helps to keep your codebase organized and up-to-date.

All Available Commands

You can find the full list of the available command in man. It will be similar to:

# Commands:
# p, pick <commit> = use commit
# r, reword <commit> = use commit, but edit the commit message
# e, edit <commit> = use commit, but stop for amending
# s, squash <commit> = use commit, but meld into previous commit
# f, fixup <commit> = like "squash", but discard this commit's log message
# x, exec <command> = run command (the rest of the line) using shell
# b, break = stop here (continue rebase later with 'git rebase --continue')
# d, drop <commit> = remove commit
# l, label <label> = label current HEAD with a name
# t, reset <label> = reset HEAD to a label
# m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]
# .       create a merge commit using the original merge commit's
# .       message (or the oneline, if no original merge commit was
# .       specified). Use -c <commit> to reword the commit message.
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.

Conclusion

Git Interactive Rebase is a powerful feature in Git that allows you to edit, reorder, and squash multiple commits into a single commit. As a software engineer, it’s important to understand how to use it effectively to keep your code organized and up-to-date. With this step-by-step guide, you’ll be able to master Git Interactive Rebase in no time!

Additional resources for learning Git Interactive Rebase include online tutorials and the official Git documentation. Keep practicing and don’t be afraid to experiment with Git Interactive Rebase to see what works best for your workflow. Good luck!