README

Resolving merge conflicts

Merge conflicts. As the name implies, they're terrifying. No one likes conflict, right? But they're an inevitable part of collaborative coding, so let's get some hands-on experience with resolving them.

Creating the conflict

1. Fork this repo.
2. Clone the forked repo [make sure you clone your fork, *yourusername*/mergeconflict, not mine, FlukeAndFeather/mergeconflict].
3. Create a new branch called dev and check it out.
4. Edit README.md. Make a note of where you edited it!
5. Check out main branch.
6. Make a conflicting change. Change the same line as you did in step 4, but do it differently.
7. Return to the dev branch.
8. Merge main into dev

Resolving the conflict

You should see an error message that includes something like:

CONFLICT (content): Merge conflict in README.md

If you open README.md, you'll see git inserted text to explain the merge conflict.

<<<<<<< HEAD
[The changes you made in the dev branch]
=======
[The changes you made in the main branch]
>>>>>>> main

You have three options now.

1. Accept the current change (i.e., the one in dev).
2. Accept the incoming change (i.e., the one in main).
3. Use your judgement to merge the changes manually.

For option 1, delete <<<<<<< HEAD, and everything from ======= to >>>>>>> main. This only leaves the changes from the dev branch. For option 2, you'd do the complement. Delete everything from <<<<<<< HEAD to =======, then delete >>>>>>> main. For option 3, you merge the two changes as you see fit. Write the new code you want, then delete the text added by git (i.e., everything from <<<<<<< HEAD to >>>>>>> main).

After you've finished editing the text, let git know you're done by committing.

git commit -a -m "merge main into dev"

Then call git log to verify it worked.

Summary

Congratulations, you've resolved a merge conflict! See, they're not so bad. Here are the core ideas.

• Git can automatically merge code changes when they occur on different lines.
• Merge conflicts happen when two branches have different changes to the same code.
• Follow git's decorators (<< HEAD, >> [other branch]) to find the conflict.
• Resolve conflicts manually, then commit to finish the process.