Resolving Merge Conflicts | Branching and Merging: Working on Features Independently | Getting Started with GitHub: A Beginner's Guide to Version Control and Collaboration

Even with the best planning, sometimes your independent work on a branch might clash with changes made elsewhere. When you try to merge a branch and Git can't automatically figure out how to combine the changes, you've encountered a merge conflict. This is a common part of working collaboratively, and understanding how to resolve them is crucial. Think of it as Git saying, 'I'm not sure which version of this code you want to keep, so I need your help!'

When a merge conflict occurs, Git will pause the merge process and mark the files with conflicts. You'll see special markers within the affected files that look like this:

<<<<<<< HEAD
// Code from your current branch (HEAD)
console.log('Hello from main!');
=======
// Code from the branch you are merging in
console.log('Hello from feature-branch!');
>>>>>>> feature-branch

These markers help you identify the conflicting sections:

<<<<<<< HEAD: Indicates the start of the changes from your current branch (usually main or master if you're merging into it).
=======: Separates the changes from your current branch and the changes from the branch you are merging.
>>>>>>> [branch-name]: Indicates the end of the changes from the branch you are merging in.

To resolve a merge conflict, you need to manually edit the conflicted files. Your goal is to decide which code to keep, or to combine parts of both. You will remove the conflict markers (<<<<<<<, =======, >>>>>>>) and leave only the desired code.

Here's a typical workflow for resolving conflicts:

Identify Conflicted Files: Git will tell you which files have conflicts. You can also run git status to see them listed under 'Unmerged paths'.

git status

Open Conflicted Files: Open each file listed by git status in your code editor.

Manually Edit: Carefully examine the conflict markers. Decide which code to keep. You might:
- Keep the code from your current branch (HEAD).
- Keep the code from the branch you're merging.
- Combine parts of both.
- Write entirely new code to replace both conflicting sections. Crucially, remove all conflict markers (<<<<<<<, =======, >>>>>>>) after you've made your decision.

Stage the Resolved Files: Once you've edited and saved a conflicted file, you need to tell Git that you've resolved the conflict by staging it.

git add <conflicted-file-name>

Commit the Merge: After staging all resolved files, commit the merge. Git will often pre-populate a commit message for you, but you can adjust it if needed.

git commit

If you're unsure about the changes or make a mistake, you can often abort the merge process before committing.

git merge --abort

Many code editors have built-in tools that can help visualize and resolve merge conflicts, making the process much smoother. Look for features like 'Merge Conflicts' or 'Resolve Conflicts' in your editor's menus.

graph TD
    A[Start Merge] --> B{Git Detects Conflict?}
    B -- Yes --> C[Mark Conflicts in Files]
    C --> D[Manually Edit Files]
    D --> E[Remove Conflict Markers]
    E --> F[Stage Resolved Files]
    F --> G[Commit Merge]
    B -- No --> H[Merge Successful]
    G --> H
    D --> I[Abort Merge if Needed]

<<<<<<< HEAD // Code from your current branch (HEAD) console.log('Hello from main!'); ======= // Code from the branch you are merging in console.log('Hello from feature-branch!'); >>>>>>> feature-branch

graph TD A[Start Merge] --> B{Git Detects Conflict?} B -- Yes --> C[Mark Conflicts in Files] C --> D[Manually Edit Files] D --> E[Remove Conflict Markers] E --> F[Stage Resolved Files] F --> G[Commit Merge] B -- No --> H[Merge Successful] G --> H D --> I[Abort Merge if Needed]