How to rebase a fixup commit?

Rebasing a Fixup Commit

Rebasing a fixup commit is a common task in Git that allows you to clean up your commit history by squashing or rearranging your commits. A fixup commit is a special type of commit that is typically used to fix a mistake or a minor issue in a previous commit. In this guide, we'll explore the steps to rebase a fixup commit and discuss the benefits of this process.

Understanding Fixup Commits

In Git, a fixup commit is a special type of commit that is used to fix a mistake or a minor issue in a previous commit. It is typically created using the git commit --fixup command, which automatically creates a new commit with the word "fixup" followed by the commit hash of the commit it is fixing.

For example, let's say you have the following commit history:

commit 1: Initial commit
commit 2: Implemented feature A
commit 3: Fixed a bug in feature A
commit 4: Implemented feature B

If you discover a minor issue in commit 2, you can create a fixup commit using the following command:

git commit --fixup commit2_hash

This will create a new commit that looks like this:

commit 1: Initial commit
commit 2: Implemented feature A
commit 3: Fixed a bug in feature A
commit 4: Implemented feature B
commit 5: fixup! commit2_hash

The fixup commit is designed to be easily squashed into the original commit it is fixing, which helps to keep your commit history clean and organized.

Rebasing a Fixup Commit

To rebase a fixup commit, you can use the git rebase -i command. This command allows you to interactively rebase your commits, which means you can rearrange, squash, or even edit your commits.

Here's the step-by-step process to rebase a fixup commit:

1. Start the interactive rebase: Run the following command to start the interactive rebase:

   git rebase -i commit2_hash~1

   This command will open an editor with the list of commits that will be rebased, starting from the commit before the fixup commit.

2. Squash the fixup commit: In the editor, you'll see the list of commits that will be rebased. Find the line that corresponds to the fixup commit and change the word "pick" to "squash" (or "s" for short) to indicate that you want to squash it with the previous commit.

   pick commit2_hash Implemented feature A
   s fixup_commit_hash fixup! commit2_hash
   # other commits...

3. Save and exit: Save the changes and exit the editor. Git will now squash the fixup commit into the previous commit, resulting in a cleaner commit history.

4. Resolve any conflicts: If there are any conflicts between the commits, Git will pause the rebase process and ask you to resolve the conflicts. You can do this by editing the conflicting files, adding the resolved changes, and then continuing the rebase.

5. Force push the changes: After the rebase is complete, you'll need to force push the changes to the remote repository, as the commit history has been rewritten. Use the following command:

   git push --force-with-lease

   The --force-with-lease option ensures that you don't accidentally overwrite someone else's work.

Here's a Mermaid diagram that illustrates the process of rebasing a fixup commit:

Rebasing a fixup commit is a powerful technique that can help you maintain a clean and organized commit history. By squashing the fixup commit into the original commit, you can ensure that your commit history is easy to understand and navigate, which can be especially helpful when working on large or complex projects.