lib/grape/formatter/xml.rb in grape-0.2.6 vs lib/grape/formatter/xml.rb in grape-0.3.0

@@ -2,10 +2,11 @@
   module Formatter
     module Xml
       class << self
 
         def call(object, env)
-          object.respond_to?(:to_xml) ? object.to_xml : object.to_s
+          return object.to_xml if object.respond_to?(:to_xml)
+          raise Grape::Exceptions::InvalidFormatter.new(object.class, 'xml')
         end
 
       end
     end
   end