Understanding Git Squash

Git squash is a function within the Git version control system that allows multiple commits to be combined into a single commit. This can be particularly useful in various scenarios such as cleaning up commit history before merging branches, condensing a set of experimental or corrective commits into a single, cohesive unit, or preparing a clean, organized pull request.

When and Why to Use Git Squash

• To clean up commit history: Git squash is ideal for condensing work-in-progress commits into a more structured and readable format before merging into the main branch
• To simplify complex logs: In projects where multiple minor changes like typo fixes or small adjustments have been made, squashing these into a single commit can help keep the project timeline understandable
• Before merging branches: Squashing commits can help ensure that branches are merged cleanly without cluttering the project history with every single commit made in the feature branch

Benefits of Squashing Commits

Cleaner Commit History

One of the primary advantages of squashing commits is achieving a cleaner, more manageable commit log. This simplification helps anyone looking into the project history to grasp the significant changes without getting lost in a sea of minor updates.

Enhanced Collaboration

When working in a team, a tidy commit history can significantly improve the collaborative process. It reduces the complexity new members face when they join the project and helps maintain clarity about what changes have been made and why.

Easier Rollbacks

By consolidating multiple related changes into a single commit, it becomes easier to revert changes if something goes wrong. Instead of having to undo or fix several individual commits, developers can revert a single squashed commit, which can save a lot of time and reduce the risk of errors in the rollback process.

Step-by-Step Guide to Squashing Commits

Squashing commits in Git can streamline your project’s history by condensing multiple small updates into a single, comprehensive commit. This section will guide you through the process using interactive rebase.

Preparing Your Branch

Before you begin the squash process, ensure your working branch is up-to-date and checked out:

# Switch to your feature branch
git checkout feature-branch

# Update your branch (if necessary)
git fetch origin
git rebase origin/main

Interactive Rebase Method

Interactive rebase is the most flexible and commonly used method for squashing commits. It allows you to edit, reorder, combine, and remove commits interactively.

Step 1: Start an interactive rebase:

git rebase -i HEAD~n

Replace n with the number of commits you want to review. This command will open a text editor with a list of recent commits in your branch.

Step 2: Choose which commits to squash. In the text editor, you’ll see a list of commits prefixed with the word pick. To squash commits, replace pick with squash next to the commits you want to combine:

pick 01d1124 Add login feature
squash 123d112 Fix typo in login feature
squash 1a2b123 Improve performance of login feature

Handling Merge Conflicts During Squash

One of the challenges when squashing commits in Git is the potential for merge conflicts. These conflicts can occur when the changes in the commits being squashed overlap with changes in other parts of your project.

Resolving Conflicts

• Edit the conflicting files: Open the files listed with conflicts in your code editor and look for conflict markers (<<<<<<<, =======, >>>>>>>)
• Mark conflicts as resolved: After making necessary changes, add them back to the staging area with git add <filename>
• Continue the rebase: Use git rebase --continue to complete the squash process

Best Practices for Git Squash

Do’s

• Squash during feature development: Consider squashing commits regularly throughout development rather than waiting until merge time
• Use descriptive commit messages: When squashing, revise the commit message to reflect the overall impact of the combined changes
• Test before squashing: Make sure the branch is fully functional and tested before squashing
• Communicate with your team: Keep your team informed about your squashing plans in collaborative environments

Don’ts

• Don’t lose granular history: Be careful not to squash commits that contain important individual changes
• Avoid excessive squashing: Don’t squash commits indiscriminately—each squashed commit should still be meaningful
• Don’t squash shared commits: Never squash commits that have already been pushed to a shared repository where others might have based work on them