Use IntelliJ or WebStorm as git mergetool

Configure Sourcetree

The merge tool that ships with JetBrain's IntelliJ IDEA or WebStorm is really awesome and way better than FileMerge. It is quite simple to configure SourceTree to use it as the default mergetool:

1. Open the SourceTree preferences and select the Diff tab

2. Choose Custom both as Visual Diff Tool and as Merge Tool

3. Paste the following commands into the textfields:

   • Diff Command: /Applications/IntelliJ\ IDEA.app/Contents/MacOS/idea diff

     • Arguments: $(cd $(dirname "$LOCAL") && pwd)/$(basename "$LOCAL") $(cd $(dirname "$REMOTE") && pwd)/$(basename "$REMOTE")

   • Merge Command: /Applications/IntelliJ\ IDEA.app/Contents/MacOS/idea merge

     • Arguments: $(cd $(dirname "$LOCAL") && pwd)/$(basename "$LOCAL") $(cd $(dirname "$REMOTE") && pwd)/$(basename "$REMOTE") $(cd $(dirname "$BASE") && pwd)/$(basename "$BASE") $(cd $(dirname "$MERGED") && pwd)/$(basename "$MERGED")

4. Close the settings. Happy merging!

Git in general

To manually change the mergetool for git in general follow these steps:

1. Open the ~/.gitconfig file with your favorite editor

2. Add these lines somewhere in the config:

   [merge]
           tool = intellij
   [difftool "intellij"]
           cmd = /Applications/IntelliJ\\ IDEA.app/Contents/MacOS/idea diff $(cd $(dirname \"$LOCAL\") && pwd)/$(basename \"$LOCAL\") $(cd $(dirname \"$REMOTE\") && pwd)/$(basename \"$REMOTE\")
   [mergetool "intellij"]
           cmd = /Applications/IntelliJ\\ IDEA.app/Contents/MacOS/idea merge $(cd $(dirname \"$LOCAL\") && pwd)/$(basename \"$LOCAL\") $(cd $(dirname \"$REMOTE\") && pwd)/$(basename \"$REMOTE\") $(cd $(dirname \"$BASE\") && pwd)/$(basename \"$BASE\") $(cd $(dirname \"$MERGED\") && pwd)/$(basename \"$MERGED\")
           trustExitCode = true
   

Downsides

It takes a few more seconds to launch the IntelliJ merge tool than to launch FileMerge, but it is definitely worth waiting.

Credits

Based on this article on coderwall: https://coderwall.com/p/gc_hqw/use-intellij-or-webstorm-as-your-git-diff-tool-even-on-windows