Add support for Rails engines routes in request specs

features/request_specs/request_spec.feature

@@ -112,3 +112,43 @@ Feature: request spec
     """
     When I run `rspec spec/requests/widget_management_spec.rb`
     Then the example should pass
+
+  Scenario: using engine route helpers
+    Given a file named "spec/requests/widgets_spec.rb" with:
+      """ruby
+      require "rails_helper"
+
+      # A very simple Rails engine
+      module MyEngine
+        class Engine < ::Rails::Engine
+          isolate_namespace MyEngine
+        end
+
+        class LinksController < ::ActionController::Base
+          def index
+            render plain: 'hit_engine_route'
+          end
+        end
+      end
+
+      MyEngine::Engine.routes.draw do
+        resources :links, :only => [:index]
+      end
+
+      Rails.application.routes.draw do
+        mount MyEngine::Engine => "/my_engine"
+      end
+
+      module MyEngine
+        RSpec.describe "Links", :type => :request do
+          include Engine.routes.url_helpers
+
+          it "redirects to a random widget" do
+            get links_url
+            expect(response.body).to eq('hit_engine_route')
+          end
+        end
+      end
+      """
+    When I run `rspec spec`
+    Then the example should pass

lib/generators/rspec/scaffold/templates/request_spec.rb

@@ -14,6 +14,10 @@
 
 <% module_namespacing do -%>
 RSpec.describe "/<%= name.underscore.pluralize %>", <%= type_metatag(:request) %> do
+  <% if mountable_engine? -%>
+    include Engine.routes.url_helpers
+  <% end -%>
+
   # <%= class_name %>. As you add validations to <%= class_name %>, be sure to
   # adjust the attributes here as well.
   let(:valid_attributes) {

spec/generators/rspec/scaffold/scaffold_generator_spec.rb

@@ -39,6 +39,15 @@
       it { is_expected.to contain('renders a JSON response with the post') }
       it { is_expected.to contain('renders a JSON response with errors for the post') }
     end
+
+    describe 'in an engine' do
+      before do
+        allow_any_instance_of(::Rails::Generators::NamedBase).to receive(:mountable_engine?).and_return(true)
+        run_generator %w[posts --request_specs]
+      end
+
+      it { is_expected.to contain('Engine.routes.url_helpers') }
+    end
   end
 
   describe 'standard controller spec' do