Auto-resolve the most common merge conflicts

[natemcmaster]

Let's see if we can update scripts/GitHubMergeBranches.ps1 to handle this better.

cc @pranavkm @pakrym

[natemcmaster]

Just throwing out ideas. What if we let users specify a merge strategy per file/globbing pattern via korebuild.json? Most repos could have something like this:

{
  "mergeStrategies": {
    "korebuild-lock.txt": "Ours",
    "build/dependencies.props": { "name": "XmlDepsMerge", "options": "HighestVersion" },
    "submodules/*/": "Ours"
  }
}

Something like this would be great in aspnet/Universe which always has a bunch of merge conflicts.

[pranavkm]

That seems nice. For the deps file, do we actually want to merge, rather than take ours and for the master branch UpdateRepos to update it?

[natemcmaster]

Yeah, the deps file needs a special merge because it's not uncommon to add/delete version variables as dependencies shift.

[pakrym]

.\run merge-stuff that would detect if there are conflicts in deps/lock/other special files and fix merges for them. The bot can run it and commit the result or a person can do it too.

[natemcmaster]

I think we should have the tool take in standard git mergetool arguments such as $BASE $LOCAL $REMOTE $MERGED. Then you should be able to run git mergetool --tool=korebuild and it will do its magic

[weshaggard]

This is definitely going to be an interesting issue for more teams that start to on-board this automation. Do you guys already have a custom merge tool that automatically handle these merges? If so how hard is it to factor it out from korebuild so other might use it when we move this to arcade?

[natemcmaster]

we don't already have a merge tool. I'm currently thinking that if we do, we might as well implement it in arcade so it can be easily used by everyone.

[natemcmaster]

Putting this in the backlog as low priority for now.

[pranavkm]

Close? We don't have this issue any longer.