Use ruby file: ".ruby-version" when possible about rails HOT 6 OPEN

Any reason why we are trying to add the Ruby version on the Gemfile? Right now, the only tool that actually doesn't know how to read .ruby-version is Heroku, and I'm pretty sure we can teach Heroku to read it.

from rails.

I had to revert the change because it blocks devcontainers. See 707b5cb.

I'll reapply it when we have our own devcontainer ruby images.

from rails.

The original addition was here:

• #30007
• #30016

I don't recall whether there is now, or was historically, a difference in how Bundler will resolve a gemfile given the presence/absense of a ruby directive -- beyond the obvious hard-stop if the running version doesn't match.

In that original PR, @deivid-rodriguez recommended ruby RUBY_VERSION instead of duplicating the value; that still strikes me as a bit of a warty [and tautological] spelling, even compared to the new file: syntax... but it does leave me wondering what we lose by just omitting the line entirely.

from rails.

Spellings aside, the fact the file: syntax locks us so rigidly to a precise version (per 707b5cb) is IMO, Quite Unfortunate.

from rails.

We can also do ruby "~> 3.2.0" if we need to specify a version to match more what you expect this check do to. It is still duplicating the value, but at least it will not hard fail anymore.

So far, I don't know what we lose by omitting the ruby line. If all tooling is already reading from .ruby-version, that alone should keep consistent resolution for bundler.

from rails.

I think ruby DSL just adds an extra dependency on the language version for your app. I think people will typically use it when directly depending on Ruby features particular to some Ruby versions. Transitive dependencies may or may not add a dependency on the language version. By using the Ruby DSL, you make what the application supports explicit. As mentioned, ruby can take a relaxed or exact requirement, making the application more or less picky when run on different rubies.

I think it's up to each user/use case what to use. Maybe for freshly generated Rails apps it's indeed best to be as flexible as possible by avoiding the ruby line altogether.

from rails.