Alex Kahn

Working Through Git Conflicts in Vim

October 12, 2011

In this post I present a workflow I use to help me efficiently go through Git merge conflicts and correct them. It eliminates some of the typing and tedium involved in this process.

It starts with a shell alias, conflicts. The alias is defined as:

alias conflicts="git ls-files --unmerged | cut -f2 | uniq"

In Git, unmerged means a file that couldn’t be merged because of a conflict. So this Git command lists all of the objects containing conflicts. I pipe that command’s output to cut -f2 to get the second column of its output, the filenames. I then remove repeat entries using uniq, since this ls-files command outputs multiple objects for each conflict.

When I want to start resolving conflicts, I issue the command conflicts | xargs mvim. xargs is a powerful tool that takes its standard input – in this case, a list of files – and and provides that to a command as arguments. So, MacVim receives the list of conflicting files as arguments and loads the files into its buffer list.

I then fix the first conflict. If I’m dealing with a particularly long file, I use / to search for <<<< or other such conflict markers that Git places in the file.

When I’m done fixing the conflict, I execute :Git add % to add the file to the Git index. fugitive.vim, Time Pope’s essential Git intergation tool for Vim, provides the :Git command which passes through your command to the git command line. On the Vim command line % refers to the current file.¹

Having fixed a conflict and added a file to the Git index, I’m ready to deal with the next conflict. To get to the next conflicted file I use :bdelete, or :bd for short. Since we started Vim with a series of files as command line arguments, the buffer list is loaded with all the files we need to edit. :bdelete discards the current one and loads the next one. I repeat this process until there are no buffers left.

Once there are no remaining conflicts, I close my Vim window, go back to a terminal, and complete the merge using gc. What is gc? It’s an alias for git commit --verbose. Verbose commit output is awesome because it shows exactly what you’re about to commit. It saves me the step of doing git diff before each commit. I never want to commit without --verbose.

And that’s it. If this tended to be a long process or one I undertook more often, I could automate it further by creating a Vim command that combines the git add and :bdelete steps. As it stands, this workflow eliminates typing out long filenames and introduces a pleasant rhythm to this process. I hope this post has inspired you to script the tedious workflows in your Unix life. What tedious operations would you like to automate away?