Use Visual Studio to merge code for an AX 2012 CU

I'm working on upgrading an AX 2012 WMS solution to CU 10. I have a lot of modifications to the mobile device solution and I need to merge these into the CU 10 code.

Many methods in the mobile solution framework have several hundred lines of code. The largest method I have come across has almost 2800 lines of code.

The AX internal code compare and merge tool is not great in dealing with such large methods. Adding or removing a single line can easily take up to 20 minutes. So this is just not a viable solution for a simple CU upgrade.

I have moved to file based comparison, using Visual Studio, now. There is a few more things I need to keep track of myself, I need to export SYP and VAR files manually and import the merged file manually, but the compare and merge works very fast. Here is a great explanation about how you use Visual Studios merge tool to merge files: https://roadtoalm.com/2013/10/22/use-visual-studio-as-your-diff-and-merging-tool-for-local-files/

You can find of plenty other tools for compare and merge on the Internet, but you probably already have a Visual Studio license. Here is an overview of other tools: https://en.wikipedia.org/wiki/Comparison_of_file_comparison_tools