Connections don't have references to their open transactions

[matthewmcgarvey]

Right now if you want to use a transaction, you have to hold onto a reference to it. In Avram, I'm working on adding the ability to run specs in a transaction that is rolled back instead of truncating the database for a major speed improvement. To do that, I monkey patched onto DB::Connection a list of transactions that functions as a stack where the first item in the list would be the parent transaction and any transactions after that would be children. I think this would be a useful thing to have in the actual library.

Reference: luckyframework/avram#780

Inspiration is from Rails: https://github.com/rails/rails/blob/619e523613e942d3fd16b43fc60be9060a29622d/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb#L226

[bcardiff]

I think is doable without much overhead. Transactions although nested are always linear so a stack make sense.

It's either a stack or just the most recent one and have from there a traversal of the ancestors.

It's important to clear the stack/latest when closing the transaction to avoid holding a reference to the connection probably.

But as commented on the linked issue, I think that whoever starts the transaction can hold a reference to it, and I don't see right now many use cases for accessing the current transactions, other than debugging which is always nice :-).

I would like to have more use cases in mind for moving forward.