Workaround Rails.configuration.database_configuration being {}

[bdunne]

If you don't have a config/database.yml and only ENV["DATABASE_URL"], Rails.configuration.database_configuration will be {}, so you'll get an undefined [] for nil error.

While attempting to fix that in rails/rails#29305, I was told that it was not intended to be the public interface. So I'm changing this PR to always use ActiveRecord::Base.configurations instead.

[NickLaMuro]

I see I was booted of the reviewer list here, but I think this looks fine from my end (as far as it shouldn't break what I had already). Not sure we want to silently pass on the host not being there though, but maybe I am missing something of concern here.

[matthewd]

Per rails/rails#29305 (comment), this should always be using ActiveRecord::Base.configurations. (Unless it's sometimes run before the configuration is loaded, or something? In which case I'd probably try to rearrange the order instead of recreating the config-reading process, tbh.)

[bdunne]

Thanks @matthewd I updated this PR accordingly

[bdunne]

@NickLaMuro I thought you were away 🏖️ , so I wanted you to see it, but not require your response.

[miq-bot]

Checked commit bdunne@3a6cf41 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
1 file checked, 0 offenses detected
Everything looks fine. 🍪

[NickLaMuro]

@bdunne Stay-cation... but yeah.

Regarding the defined? Rails portion, I only left that part in to keep the old compatibility in place in case that was preferred/had an edge case in place (but thanks to @matthewd 's comment, it seems like it isn't).

[jrafanie]

Oh wow, TIL... I would never have guessed that the seemingly lower level ActiveRecord::Base.configurations is actually the public interface but the seemingly higher level Rails.configuration.database_configuration is really more "private".

It makes sense to do it this way if AR::Base.configurations is the public way of doing it.