Make it possible to mix `Gitlab::Routing` in

lib/gitlab/ci/status/core.rb

@@ -4,7 +4,7 @@ module Gitlab
       # Base abstract class fore core status
       #
       class Core
-        include Gitlab::Routing.url_helpers
+        include Gitlab::Routing
         include Gitlab::Allowable
 
         attr_reader :subject, :user

lib/gitlab/routing.rb

 module Gitlab
   module Routing
+    extend ActiveSupport::Concern
+
+    included do
+      include Gitlab::Routing.url_helpers
+    end
+
     # Returns the URL helpers Module.
     #
     # This method caches the output as Rails' "url_helpers" method creates an

spec/lib/gitlab/routing_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Routing do
+  context 'when module is included' do
+    subject do
+      Class.new.include(described_class).new
+    end
+
+    it 'makes it possible to access url helpers' do
+      expect(subject).to respond_to(:namespace_project_path)
+    end
+  end
+
+  context 'when module is not included' do
+    subject do
+      Class.new.include(described_class.url_helpers).new
+    end
+
+    it 'exposes url helpers module through a method' do
+      expect(subject).to respond_to(:namespace_project_path)
+    end
+  end
+end