How to squash multiple fixup commits into the original commit?

Squashing Multiple Fixup Commits into the Original Commit

In the world of Git, it's common to make multiple small commits during the development process, often including "fixup" commits to address issues or make minor changes. However, when it's time to prepare your code for a pull request or merge, you may want to consolidate these smaller commits into a single, more meaningful commit. This process is known as "squashing" commits, and it can help maintain a clean and organized Git history.

Understanding Fixup Commits

Fixup commits are a type of commit that are used to make small, incremental changes to a previous commit. They are typically used to fix typos, address code review feedback, or make other minor adjustments. Fixup commits are often denoted with the "fixup!" prefix in the commit message, indicating that they are meant to be combined with a previous commit.

Squashing Commits with Git Rebase

The process of squashing multiple fixup commits into the original commit can be accomplished using the git rebase command. Here's a step-by-step guide:

Ensure you're on the correct branch: Make sure you're on the branch where the commits you want to squash are located.
Start the interactive rebase: Run the following command to start an interactive rebase:
```
git rebase -i HEAD~<number_of_commits_to_rebase>
```
Replace <number_of_commits_to_rebase> with the number of commits you want to rebase, including the fixup commits and the original commit you want to keep.
Prepare the commits for squashing: In the text editor that opens, you'll see a list of the commits, with the oldest commit at the top. Locate the fixup commits and change the word "pick" to "fixup" (or "f" for short) for those commits. Leave the original commit with the "pick" (or "p") prefix.
```
pick 1a2b3c4 Original commit
fixup 5e6f7g8 Fixup commit 1
fixup 9h0i1j2 Fixup commit 2
```
Save and exit the editor: Once you've made the necessary changes, save the file and exit the text editor.
Rewrite the Git history: Git will now rewrite the commit history, squashing the fixup commits into the original commit. This may take a few moments, depending on the number of commits involved.
Force push the changes: After the rebase is complete, you'll need to force push the changes to your remote repository. This is because you've rewritten the commit history, and Git will see the local and remote histories as divergent. Use the following command to force push the changes:
```
git push --force-with-lease
```
The --force-with-lease option is recommended as it helps prevent accidentally overwriting changes made by other collaborators.

Here's a Mermaid diagram to visualize the process:

graph TD A[Original Commit] --> B[Fixup Commit 1] A --> C[Fixup Commit 2] B --> D[Squashed Commit] C --> D

By squashing multiple fixup commits into the original commit, you can maintain a clean and organized Git history, making it easier to understand the development process and collaborate with your team.