@jelaniwoods This should maybe go into web_git repo, but anyway. I think we should prioritize this and add a merge strategy for the development.sqlite3 file.

@raghubetina I don't understand when would a merge even occur in the student's git workflow? Since we do save the development.sqlite3 in the git History, checking out other branches shouldn't cause any merge conflicts— right?

@jelaniwoods Yes, I believe checking out other branches shouldn't cause any issues. (Although I feel like I have noticed some "Pending migration" situations when I jump back and forth between branches, which I was hoping to avoid by ungitignoring development.sqlite3; I haven't had time to try and reliably reproduce.)

It's true that we currently landed upon a merge-free workflow, with git push heroku HEAD:master -f in a single-person-only-deploying-"best"-branch situation. However in the past (e.g. on Very Best) and in the future, we'll want students to work in teams and therefore they will need to learn to merge. This quarter for example I would like to try and have them do ICPC-style problem sets during class, merging solutions and rails gradeing.

@raghubetina okay that makes sense. I assume then a merge section needs to be added to web_git at some point after the core functionality is working at acceptable speeds and without errors.

@raghubetina according to the git documentation and this answer we need to be update the git configuration to use the merge strategy, I can think of a couple ways to do this but wanted to get your opinion:

• Can run the git command in bin/setup
• Can run the git command in a separate script that only runs once per workspace
  • Can shell out command or use git gem somehow

These approaches seem mostly equivalent to me. Am overlooking something?

@jelaniwoods In the past we relied on GitHub's built-in merging UI, and I was hoping to continue to do so; I don't relish the idea of building a UI for resolving conflicts, although I suppose it wouldn't be too bad. (We could perhaps build-in a button for "Merge" that greys out when it detects that it's not a fast-forward merge, and suggests to push to GitHub and handle it there in that case.)

I would like students to

• Push to GitHub
• merge their branch to master on GitHub (resolving conflicts there)
• switch to master locally
• pull from GitHub
• checkout a new branch to work on their next task
• rinse and repeat

I thought that defining a .gitattributes file and specifying a strategy for handling development.sqlite3 might work while merging on GitHub, but now that I read that SO thread in more detail, perhaps GitHub won't be able to do it since we can't define the actual strategy on GitHub. Requires experimentation.

OH, okay. I will investigate with GitHub's merge to see if if will accept the strategy.

@raghubetina after a little research and testing, it doesn't appear that GItHub respects .gitattributes file.

This SO answer further suggests that GitHub doesn't look at the file https://stackoverflow.com/a/24382933/10481804
I tested in this PR jelaniwoods-FurtherLearning/wweeeee#8

@jelaniwoods What happens when you have conflicts in a binary file during GitHub merge? Does it let you pick one or the other, or does it just fail?

@raghubetina In the PR I tested with the conflict of development.sqlite3 couldn't be resolved in the web editor.

@jelaniwoods Blergh. I wonder how good Gitpod's built-in git UI is for merging.

@raghubetina If it's local merging we can use .gitattributes and pick a version so we don't need to resolve conflicts.

Trying to merge without .gitattributes looks tricky. There doesn't appear to be any UI change and even the diff on the command line is unhelpful.