Git Merge Rebase and Squash Explained
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Git merge, rebase, and squash are three different Git operations that manage and integrate changes from one branch into another. Each serves a specific purpose, and understanding the differences between them helps you decide which to use in various scenarios. To read more about Git, you can refer to this blog post.
Table Of Contents
Git Merge
Git merge combines changes from one branch into another by creating a merge commit. This commit has two parent commits—one from each branch—preserving the history of both branches. Merging is often used in team environments to integrate feature branches into the main branch while keeping a detailed history of contributions.
Merge commits preserve the full history, showing exactly when and how branches were integrated. The downside of using a merge commit is that it can make the commit history more complex, especially with multiple merges over time.
Git Rebase
Git rebase moves or re-applies commits from one branch to another, effectively rewriting commit history. Instead of creating a merge commit, it places your branch’s commits on top of the latest commits from the target branch. You should use rebase when you want a clean, linear history without unnecessary merge commits. Developers often rebase their feature branch onto the latest version of the main branch before merging to ensure it’s up-to-date and to avoid merge conflicts.
The advantage of using rebase is that it creates a linear commit history, making it easier to read and understand. By avoiding merge commits, the history looks like it was developed in a straight line. However, rewriting history can be dangerous if not done carefully, especially on branches shared with others. Never rebase commits that have been pushed to a public repository. Handling conflicts during a rebase can also be more complicated than during a merge.
Git Squash
Git squash combines multiple commits into a single commit. Squashing is useful for cleaning up your commit history before merging a feature branch into the main branch. You should use squash to combine several small, related commits into one logical commit before merging.
Squashing reduces noise in your commit history by consolidating multiple changes into a single commit. Each commit represents a complete, logical unit of work, which can make debugging and reviewing history easier. The disadvantage is using squash is that it eliminates the granular history of changes, which might be valuable in some cases. Squashing requires careful manual selection of commits to combine, which can be error-prone if not done correctly.
Summary Comparison
| Feature | Git Merge | Git Rebase | Git Squash |
|---|---|---|---|
| Commit History | Preserves full history with merge commits | Rewrites history for a linear appearance | Consolidates multiple commits into one |
| Best Used For | Integrating branches while keeping history intact | Cleaning up feature branches before merging | Simplifying commit history before merging |
| Advantages | Shows complete development history | Cleaner, linear history | Focused, simplified commit messages |
| Disadvantages | Can clutter history with merge commits | Can be risky when rewriting history | Loss of detailed commit history |
| Conflict Resolution | During merge, results in a merge commit | During rebase, integrated into rebased commits | N/A (part of interactive rebase) |
Conclusion
Understanding the Git Merge Rebase and Squash tools and when to use each can significantly improve your Git workflow, making your project history clearer and more manageable.
