3 files changed, 28 insertions, 9 deletions
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index 4c0d4455f9..f5dcea9158 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -325,6 +325,10 @@ module ActionDispatch
     end
 
     module Runner
+      def app
+        @app
+      end
+
       # Reset the current session. This is useful for testing multiple sessions
       # in a single test case.
       def reset!
@@ -354,8 +358,7 @@ module ActionDispatch
       # can use this method to open multiple sessions that ought to be tested
       # simultaneously.
       def open_session(app = nil)
-        app ||= @app ||= ActionController::Dispatcher.new
-        session = Integration::Session.new(app)
+        session = Integration::Session.new(app || self.app)
 
         # delegate the fixture accessors back to the test instance
         extras = Module.new { attr_accessor :delegate, :test_result }
@@ -477,5 +480,20 @@ module ActionDispatch
   #   end
   class IntegrationTest < ActiveSupport::TestCase
     include Integration::Runner
+
+    @@app = nil
+
+    def self.app
+      # DEPRECATE AC::Dispatcher fallback
+      @@app || ActionController::Dispatcher.new
+    end
+
+    def self.app=(app)
+      @@app = app
+    end
+
+    def app
+      super || self.class.app
+    end
   end
 end
diff --git a/actionpack/test/abstract_unit.rb b/actionpack/test/abstract_unit.rb
index 572a3d6fd9..aef3dd6165 100644
--- a/actionpack/test/abstract_unit.rb
+++ b/actionpack/test/abstract_unit.rb
@@ -52,11 +52,13 @@ ORIGINAL_LOCALES = I18n.available_locales.map {|locale| locale.to_s }.sort
 
 FIXTURE_LOAD_PATH = File.join(File.dirname(__FILE__), 'fixtures')
 
-ActionController::Dispatcher.middleware = ActionDispatch::MiddlewareStack.new do |middleware|
-  middleware.use "ActionDispatch::ShowExceptions"
-  middleware.use "ActionDispatch::Callbacks"
-  middleware.use "ActionDispatch::ParamsParser"
-  middleware.use "Rack::Head"
+class ActionController::IntegrationTest < ActiveSupport::TestCase
+  @@app = ActionDispatch::MiddlewareStack.new { |middleware|
+    middleware.use "ActionDispatch::ShowExceptions"
+    middleware.use "ActionDispatch::Callbacks"
+    middleware.use "ActionDispatch::ParamsParser"
+    middleware.use "Rack::Head"
+  }.build(ActionController::Routing::Routes)
 end
 
 module ActionView
diff --git a/actionpack/test/controller/dispatcher_test.rb b/actionpack/test/controller/dispatcher_test.rb
index 8d974cb745..7ef2564e5a 100644
--- a/actionpack/test/controller/dispatcher_test.rb
+++ b/actionpack/test/controller/dispatcher_test.rb
@@ -22,7 +22,6 @@ class DispatcherTest < Test::Unit::TestCase
 
   def teardown
     Dispatcher.router = @old_router
-    @dispatcher = nil
     ENV.delete 'REQUEST_METHOD'
   end
 
@@ -79,7 +78,7 @@ class DispatcherTest < Test::Unit::TestCase
       ActionController::Dispatcher.prepare_each_request = false
       Dispatcher.define_dispatcher_callbacks(cache_classes)
 
-      @dispatcher ||= Dispatcher.new
+      @dispatcher ||= ActionDispatch::Callbacks.new(Dispatcher.router)
       @dispatcher.call({'rack.input' => StringIO.new(''), 'action_dispatch.show_exceptions' => false})
     end