Git Workshop

Ready for your first Git interactive rebase? 😎

No prior experience with interactive rebasing, and not sure why you’d ever want to?
Congrats! You have found an excellent adventure.

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 🤷🏻

Reviewers 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?! The least I can do is to select the button to squash-and-merge. Hopefully nobody will want to investigate the history of this change in the future.

But even better than a squash-and-merge, would be to tidy up this branch. Let’s do that!

Interactive rebase 😎

Recommended prerequisite before diving into this Git operation, is to make sure you have a Git editor you know how to use. Adventure detour (interactive rebase will wait!): Know your Git editor

# 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.

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 with safety options
git push --force-with-lease --force-if-includes

I have cleaned up the mess, and am 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! And perhaps start looking into other commands like these:

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