Add error details to response

lib/api/errors/unwritable_property.rb

@@ -41,6 +41,8 @@ module API
           invalid_attributes.each do |attribute|
             @errors << UnwritableProperty.new(attribute)
           end
+        else
+          @details = { attribute: attributes[0] }
         end
       end
     end

lib/api/v3/errors/error_representer.rb

@@ -42,6 +42,7 @@ module API
         property :_type, exec_context: :decorator
         property :error_identifier, exec_context: :decorator, render_nil: true
         property :message, getter: -> (*) { message }, render_nil: true
+        property :details, embedded: true
 
         collection :errors,
                    embedded: true,