Include .ruby-version

[shippy]

As per thoughtbot's Best Practices, we should include a .ruby-version file in our repository.

[orenyk]

We currently specify it in our Gemfile, but either way should be fine.

[shippy]

I think the justification is that all Ruby version managers will automatically adjust the version based on the file, which they won't based on the Gemfile alone?

[mnquintana]

So this is how Bundler handles the ruby directive: http://bundler.io/v1.6/gemfile_ruby.html

I'm not sure, but the .ruby-version seems a bit redundant? Maybe the advantage is that the ruby managers are more strict about this than Bundler?

[orenyk]

This plugin allows rbenv to pick the ruby version from the Gemfile. RVM uses it out of the box, but it's the last place it will look. I think that having a .ruby-version file that's in Git would be fine, but it would be nice to have the version set in only one place. Maybe if we set up dotenv (#694) we can keep it as an environment file and pull it into both files?

[orenyk]

After rethinking this, I think we should just recommend / require everyone to use the relevant rbenv plugin so that we don't have the Ruby version defined in multiple places. I'll ask @dgoerger to put it in the dev VM and we should add it to the wiki as well. Closing!

[mnquintana]

I went back and forth on this with Shifts, and ended up deciding on adding a .ruby-version. The thing is, although a standard VM will help us a lot, at least as of right now it's only being forced upon Windows users, so everyone else needs to manually maintain their dev environments (as they should). But .ruby-version automatically changes your current ruby version in rbenv for you if you have it installed, which is something the Gemfile directive doesn't provide. Changing like, a 6 character string in exactly two places is, IMO, really trivial code duplication for the benefit of some logic-enforced standardization (especially if you add a good explanatory comment).

[orenyk]

Fair enough, it's a pretty simple fix either way. I'll move this to v4.0.