How to Resolve Merge Conflicts in a Git Pull Request?

Git is an essential tool in modern software development, enabling teams to collaborate on code efficiently. However, as projects grow in size and complexity, merge conflicts can arise when multiple developers work on the same files or branches. While conflicts are a natural part of collaboration, they can be intimidating for newcomers and frustrating for experienced developers.

This blog will walk you through the process of resolving merge conflicts during a pull request (PR), ensuring a smooth integration of code changes into your main branch.

What Is a Merge Conflict?

A merge conflict occurs when Git cannot automatically reconcile differences between two branches. This usually happens when:

• Multiple changes are made to the same line of a file.
• One developer modifies a file while another deletes it.
• Changes occur in overlapping sections of a file.

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Steps to Resolve Merge Conflicts

1. Identify the Conflict

When you attempt to merge a branch or complete a pull request, Git will notify you if conflicts are detected. These conflicts are highlighted in the terminal, listing the affected files.

CONFLICT (content): Merge conflict in <file_name>

Git pauses the merge process, allowing you to resolve the conflicts before proceeding.

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2. Open the Affected Files

Conflict markers will appear in the conflicting files, showing the differences between the two branches. They look like this:

<<<<<<< HEAD
// Changes from the current branch
=======
 // Changes from the incoming branch
>>>>>>> <branch_name>

• HEAD indicates the current branch.
• The incoming branch is the branch being merged into the current branch.

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3. Resolve the Conflicts

Manually edit the file to reconcile the conflicting changes. This involves:

• Deciding which changes to keep.
• Combining changes if both are necessary.
• Removing conflict markers (<<<<<<<, =======, >>>>>>>).

Here’s an example:

Before resolving:

<<<<<<< HEAD
color: blue;
=======
color: green;
>>>>>>> feature-branch

After resolving:

color: blue; /* Decided to keep the current branch's changes */

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4. Test Your Changes

After resolving the conflicts, it’s essential to verify that your changes do not introduce bugs or unexpected behavior. Run your project’s test suite and manually test any affected areas of the code.

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5. Mark the File as Resolved

Once you’ve resolved the conflicts and tested the changes, mark the file as resolved using the following command:

git add <file_name>

Repeat this step for all conflicted files.

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6. Complete the Merge

After marking the files as resolved, complete the merge process:

git commit

If you’re working on a pull request, push your changes to the remote branch:

git push

The pull request will automatically update to reflect the resolved conflicts.

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Best Practices for Avoiding and Managing Merge Conflicts

1. Communicate with Your Team: Coordinate with your team to avoid simultaneous changes to the same files.
2. Pull Changes Regularly: Keep your branch up-to-date with the main branch to minimize the scope of conflicts.
3. Make Smaller Changes: Work on smaller, incremental changes to reduce the likelihood of overlapping edits.
4. Use Visual Tools: Tools like GitHub, GitLab, or VS Code provide graphical interfaces for resolving conflicts, making the process easier.
5. Review Changes Thoroughly: Ensure you understand the context of both sets of changes before deciding which to keep.

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Conclusion

Merge conflicts are a natural part of collaborative development. While they can seem daunting, following a systematic approach to resolving them will ensure a smooth workflow. With practice, you’ll become proficient in managing conflicts, enabling your team to deliver high-quality code efficiently.

By adopting best practices and leveraging tools effectively, you can minimize conflicts and maintain a streamlined development process.