No prior experience with interactive rebasing — and not sure why you’d ever want to?
Excellent! You have come to the right place. I wrote this guide for you.

The problem 😵‍💫

My branch is a mess of commits. While working on this change, I accidentally deleted the wrong file, added that file back again, tested and iterated, whoops forgot to rename a variable in a test that broke the build, and finally remembered to update the readme. It’s perfectly fine that these five commits were part of my process — but there is absolutely no good reason to preserve this mess.

The lazy squash-and-merge 🤷🏻

Any reviewer of the PR will just have to ignore the mess, and I will sweep it under the rug with a squash when I merge. Cause that makes the mess go away, right?! Well… if I am not going to clean up the commits on this branch, the absolute least I can do is to make sure that I select squash and merge. The next bare minimum is to not forget the silent step (that will otherwise dump the five commit messages into the squash) before hitting Confirm squash and merge. Either way, I hope any reviewer will not care, and hopefully nobody will want to investigate the history of this change in the future.

However! I have more Git tricks up my sleeve and can do better than a lazy squash-and-merge. I know how to clean up a messy branch and since I’ve gained some practice, these steps have become a natural part of my workflow. Won’t you join me…?

Interactive rebase 😎

My strongly recommended prerequisite for this Git operation is to have a Git editor you know how to use. Here’s my guide for how to Give Yourself A Git Editor To Live With.

# Check the log, was it five commits I want to clean up?
git log -5

Yes, that looks correct. Okay, lets roll up our sleeves.

# Make a list of the 5 commits about to be rebased
git rebase --interactive HEAD~5

My Git editor will now show me a list like this:

pick 2dcd477 Add awesome feature
pick 2a76135 ops dont delete important.js
pick 69cf371 wip iterations
pick a999fe0 whoops rename variable in test
pick c7f3e47 remember readme update

In the editor, I can now use commands like this one:

s, squash <commit> = use commit, but meld into previous commit

I want to meld the 4 last commits into the first.
I can do that by replacing pick with s for squash like this:

pick 2dcd477 Add awesome feature
s 2a76135 ops dont delete important.js
s 69cf371 wip iterations
s a999fe0 whoops rename variable in test
s c7f3e47 remember readme update

After saving / writing that, the next step is the commit message(s).
The list in my editor now looks like this:

# This is a combination of 5 commits.
# This is the 1st commit message:

Add awesome feature

# This is the commit message #2:

ops dont delete important.js

# This is the commit message #3:

wip iterations

# This is the commit message #4:

whoops rename variable in test

# This is the commit message #5:

remember readme update

Note the instructions:

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.

So what I will do in this specific case, is add # in front of the scraps of commit messages for 2,3,4,5 to comment those lines out. This will leave me with Add awesome feature and probably I will now make sure to write some context to that commit message (but that is a topic for a different blog post).

After saving / writing the commit message, I want to verify that my rebase happened as intended.

# Check the log, are my 5 commits now cleaned up to be 1
git log -2

Looking good! The second commit is now something else on the main branch. 🎉

If this is a branch I have previously pushed to remote, I’m gonna need to use force to update it:

# Use the force but safety options
git push --force-with-lease --force-if-includes

I have cleaned up the mess, and ready to change the PR status from draft to ready for review.

This was just one example with a basic clean up. Practice a couple of times! That will make this operation something that feels natural, and also easier to start looking into other commands like these:

• r, reword will use commit, but edit the commit message
• f, fixup like "squash" but keep only the previous log message
• d, drop to remove commit

It’s also possible to reorder the commits just by moving them around. Have fun!

— Elisabeth