Define a SynchronousQueue for test in Action Pack.

We don't need to rely on rails/queueing in Action Pack tests

actionpack/test/abstract_unit.rb

@@ -26,7 +26,6 @@ require 'active_model'
 require 'active_record'
 require 'action_controller/caching'
 require 'action_controller/caching/sweeping'
-require 'rails/queueing'
 
 require 'pp' # require 'pp' early to prevent hidden_methods from not picking up the pretty-print methods until too late
 
@@ -35,11 +34,6 @@ module Rails
     def env
       @_env ||= ActiveSupport::StringInquirer.new(ENV["RAILS_ENV"] || ENV["RACK_ENV"] || "test")
     end
-
-    def queue
-      @queue ||= Rails::Queueing::Container.new(Rails::Queueing::SynchronousQueue.new)
-    end
-
   end
 end
 

actionpack/test/controller/assert_select_test.rb

@@ -10,6 +10,16 @@ require 'controller/fake_controllers'
 require 'action_mailer'
 ActionMailer::Base.view_paths = FIXTURE_LOAD_PATH
 
+class SynchronousQueue < Queue
+  def push(job)
+    job.run
+  end
+  alias <<  push
+  alias enq push
+end
+
+ActionMailer::Base.queue = SynchronousQueue.new
+
 class AssertSelectTest < ActionController::TestCase
   Assertion = ActiveSupport::TestCase::Assertion