keep sub-Rails connected to our in-memory database

When another Rails instance is started by Capybara, it sets up a new
connection to the test database instead of re-using our in-memory DB.

http://www.spacevatican.org/2012/8/18/threading-the-rat/

README.md

@@ -172,6 +172,10 @@ database adapter][memory_test_fix].  Otherwise, you *might* face these errors:
 
 > cannot start a transaction within a transaction
 
+For older Rails, to use SQLite3 as your test database along with browser-based
+acceptance testing frameworks such as Capybara, see
+http://www.spacevatican.org/2012/8/18/threading-the-rat/
+
 ## Configuration
 
 Tork looks for a configuration directory named `.tork/` inside its working

lib/tork/config/rails/master.rb

@@ -31,6 +31,14 @@ class Tork::Railtie < Rails::Railtie
         if File.exist? seeds = "#{Rails.root}/db/seeds.rb"
           load seeds
         end
+
+        # keep sub-Rails connected to in-memory database
+        # e.g. when another Rails is started by Capybara
+        # http://www.spacevatican.org/2012/8/18/threading-the-rat/
+        class << ActiveRecord::Base
+          memory_database_connection = ActiveRecord::Base.connection
+          define_method(:connection) { memory_database_connection }
+        end
       end
     end
   end