Less hacky test routes setup

Author: bf4

test/support/rails_app.rb

@@ -16,12 +16,20 @@ class ActiveModelSerializers::RailsApplication < Rails::Application
 end
 ActiveModelSerializers::RailsApplication.initialize!
 
+Rails.application.routes.draw do
+  get ':controller(/:action(/:id))'
+  get ':controller(/:action)'
+end
 module TestHelper
-  Routes = ActionDispatch::Routing::RouteSet.new
-  Routes.draw do
-    get ':controller(/:action(/:id))'
-    get ':controller(/:action)'
+  Routes = Rails.application.routes
+  module ControllerTests
+    def setup
+      super
+      @routes = TestHelper::Routes
+    end
   end
-
-  ActionController::Base.send :include, Routes.url_helpers
+end
+ActiveSupport.on_load(:action_controller) do
+  include TestHelper::Routes.url_helpers
+  ActionController::TestCase.send :include, TestHelper::ControllerTests
 end

test/support/test_case.rb

@@ -1,8 +1,4 @@
 ActionController::TestCase.class_eval do
-  def setup
-    @routes = TestHelper::Routes
-  end
-
   # For Rails5
   # https://github.com/rails/rails/commit/ca83436d1b3b6cedd1eca2259f65661e69b01909#diff-b9bbf56e85d3fe1999f16317f2751e76L17
   def assigns(key = nil)