Navigating Pull Request Conflicts: Practical Examples

Pull request conflicts can be a common hurdle in version control systems. In this article, we will explore what a pull request conflict is, why it occurs, and provide practical examples to illustrate how to resolve them effectively.
By Jamie

What is a Pull Request Conflict?

A pull request conflict occurs when changes from different branches in a version control system (like Git) overlap in a way that the system cannot automatically merge them. This typically happens when two or more developers make edits to the same lines of code or when one developer modifies a file that another developer has deleted.

Example Scenario 1: Simultaneous Edits

Situation:

  • Branch A: Developer Alice creates a feature branch and modifies a function in app.js.
  • Branch B: Developer Bob also creates a feature branch and edits the same function in app.js.

Outcome:

When Alice submits a pull request to merge Branch A into the main branch, Git detects a conflict because both branches have changes on the same lines of the function.

Resolution Steps:

  1. Alice and Bob will both need to pull the latest changes from the main branch into their feature branches.
  2. They will resolve the conflict manually in app.js by choosing which changes to keep or integrating both changes.
  3. After resolving, they will commit the changes and push their respective branches.
  4. Finally, they can proceed to merge their pull requests.

Example Scenario 2: Deletion and Modification

Situation:

  • Branch C: Developer Charlie deletes a file called config.yaml in his feature branch.
  • Branch D: Developer Dana modifies the same file config.yaml in her feature branch.

Outcome:

When Dana attempts to merge her pull request, she will encounter a conflict because config.yaml has been deleted in Charlie’s branch while being modified in her own.

Resolution Steps:

  1. Dana will need to pull the latest changes from the main branch, which includes Charlie’s deletion.
  2. She must decide whether she wants to keep the modifications or accept the deletion.
  3. If she chooses to keep her changes, she can restore the file and integrate her modifications.
  4. After resolving the conflict, Dana commits her changes and can successfully merge her pull request.

Conclusion

Pull request conflicts are a natural part of collaborative software development. By understanding the common scenarios that lead to these conflicts and following systematic resolution steps, developers can maintain a smooth workflow. Always remember to communicate with your team and review changes carefully to ensure that everyone is on the same page.