4  Merging

4.1 Merge Conflicts

Merge conflicts arise when there are multiple commits to a single file that are in conflict and git isn’t sure which one to use.

4.1.1 On Local Machine

Merge conflicts that occur while doing git pull on your local machine will be indicated in the git bash.

USERNAME@MACHINE OS PATH/TO/REPO (main)
$ git pull origin main 
From https://github.com/ORG/REPO
* branch            main       -> FETCH_HEAD
Auto-merging FILE
CONFLICT (content): Merge conflict in FILE
Automatic merge failed; fix conflicts and then commit the result.

USERNAME@MACHINE OS PATH/TO/REPO (main|MERGING)
$

Open up the FILE and you will see the following format for each conflict:

<<<<<<< HEAD  
Code made by change B
==========
Code made by change A
>>>>>>>>>>>>> COMMIT

Keep the code you want in the file and remove the conflict indicator lines of code:

• <<<<<<< HEAD
• ==========
• >>>>>>>>>>>>> COMMIT

Save and commit those changes and if the merge is resolved, the MERGING indicator will be removed from the git bash. Then you can push up to GitHub.

USERNAME@MACHINE OS PATH/TO/REPO (main|MERGING)
$ git add FILE 

USERNAME@MACHINE OS PATH/TO/REPO (main|MERGING)
$ git commit -m 'resolve merge' 

USERNAME@MACHINE OS PATH/TO/REPO (main)
$ git push origin main 

4.1.2 GitHub Pull Requests

Conflicts generally arise when creating a pull request when different commits have been made to same file on the different branches.

When on GitHub in a specific Pull Request you can click on ‘Resolve Conflicts’ button and you will be able to address each conflict which will appear as follows:

<<<<<<< DEV_BRANCH  
Code made by change B
==========
Code made by change A
>>>>>>>>>>>>> MAIN_BRANCH

Similar to on your local machine, keep which code you want and remove the conflict indicator lines of code.

Once all conflicts are resloved, you will then be able to merge and complete the pull request.