assert_existence_of_template_file

# File actionpack/lib/action_controller/base.rb, line 1265
      def assert_existence_of_template_file(template_name)
        unless template_exists?(template_name) || ignore_missing_templates
          full_template_path = template_name.include?('.') ? template_name : "#{template_name}.#{@template.template_format}.erb"
          display_paths = view_paths.join(':')
          template_type = (template_name =~ /layouts/i) ? 'layout' : 'template'
          raise(MissingTemplate, "Missing #{template_type} #{full_template_path} in view path #{display_paths}")
        end
      end