Fix tests

lib/datagrid/engine.rb

@@ -5,11 +5,16 @@
 module Datagrid
   # @!private
   class Engine < ::Rails::Engine
+    def self.extend_modules
+      ActionView::Base.send(:include, Datagrid::Helper)
+      ActionView::Helpers::FormBuilder.send(:include, Datagrid::FormBuilder)
+    end
+
     initializer "datagrid.helpers" do
       ActiveSupport.on_load :action_view do
-        ActionView::Base.send(:include, Datagrid::Helper)
-        ActionView::Helpers::FormBuilder.send(:include, Datagrid::FormBuilder)
+        Engine.extend_modules
       end
     end
+
   end
 end

spec/datagrid/helper_spec.rb

@@ -662,7 +662,6 @@ def name
   end
 
   describe ".datagrid_header" do
-
     it "should support order_by_value colums" do
       grid = test_report(order: "category") do
         scope { Entry }

spec/spec_helper.rb

@@ -109,8 +109,8 @@ def action_view_template
     File.expand_path("../../app/views", __FILE__),
     File.expand_path("../support/test_partials", __FILE__),
   ], {})
-  klass = ActionView::Base.respond_to?(:with_empty_template_cache) ? ActionView::Base.with_empty_template_cache : ActionView::Base
-  template = klass.new(context, {}, ::ActionController::Base.new)
+  Datagrid::Engine.extend_modules
+  template = ActionView::Base.with_empty_template_cache.new(context, {}, ::ActionController::Base.new)
   allow(template).to receive(:protect_against_forgery?).and_return(false)
   template
 end