Explicitly require test/unit so tests autorun

railties/lib/test_help.rb

@@ -4,6 +4,10 @@
 # so fixtures are loaded to the right database
 silence_warnings { RAILS_ENV = "test" }
 
+require 'test/unit'
+require 'active_support/test_case'
+require 'active_controller/test_case'
+require 'action_view/test_case'
 require 'action_controller/integration'
 require 'action_mailer/test_case' if defined?(ActionMailer)