Auto-include url_helpers for Rails-apps. Fixes #563

test/test_helper.rb

@@ -20,5 +20,7 @@ end
 ActionController::TestCase.class_eval do
   def setup
     @routes = TestHelper::Routes
+
+    Rails.application.routes.default_url_options[:host] = 'http://example.com' if defined?(Rails)
   end
 end

test/unit/active_model/serializer/url_helpers_test.rb

@@ -0,0 +1,35 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class UrlHelpersTest < Minitest::Test
+      include Rails.application.routes.url_helpers
+
+      def setup
+        Object.const_set 'UserController', Class.new(ActionController::Base) do
+          def show
+            render text: 'profile'
+          end
+        end
+
+        Rails.application.routes.draw do
+          get '/profile/:id', as: :profile, controller: :user, action: :show
+        end
+      end
+
+      def test_url_helpers_are_available
+        serializer = Class.new(ActiveModel::Serializer) do
+          attributes :url
+
+          def url
+            profile_url(id: object.object_id)
+          end
+        end
+        profile = Profile.new
+
+        assert_equal({ url: profile_url(id: profile.object_id) },
+                     serializer.new(profile).as_json)
+      end
+    end
+  end
+end