Include routes.mounted_helpers into integration tests

In integration tests, you might want to use helpers from engines that
you mounted in your application. It's not hard to add it by yourself,
but it's unneeded boilerplate. mounted_helpers are now included by
default. That means that given engine mounted like:

    mount Foo::Engine => "/foo", :as => "foo"

you will be able to use paths from this engine in tests this way:

    foo.root_path #=> "/foo"

(closes #6573)

1 files changed, 19 insertions, 0 deletions

diff --git a/actionpack/test/controller/integration_test.rb b/actionpack/test/controller/integration_test.rb
index fb41dcb33a..f18bf33969 100644
--- a/actionpack/test/controller/integration_test.rb
+++ b/actionpack/test/controller/integration_test.rb
@@ -538,11 +538,26 @@ class ApplicationIntegrationTest < ActionDispatch::IntegrationTest
     @routes ||= ActionDispatch::Routing::RouteSet.new
   end
 
+  class MountedApp
+    def self.routes
+      @routes ||= ActionDispatch::Routing::RouteSet.new
+    end
+
+    routes.draw do
+      get 'baz', :to => 'application_integration_test/test#index', :as => :baz
+    end
+
+    def self.call(*)
+    end
+  end
+
   routes.draw do
     get '',    :to => 'application_integration_test/test#index', :as => :empty_string
 
     get 'foo', :to => 'application_integration_test/test#index', :as => :foo
     get 'bar', :to => 'application_integration_test/test#index', :as => :bar
+
+    mount MountedApp => '/mounted', :as => "mounted"
   end
 
   def app
@@ -555,6 +570,10 @@ class ApplicationIntegrationTest < ActionDispatch::IntegrationTest
     assert_equal '/bar', bar_path
   end
 
+  test "includes mounted helpers" do
+    assert_equal '/mounted/baz', mounted.baz_path
+  end
+
   test "route helpers after controller access" do
     get '/'
     assert_equal '/', empty_string_path