lib/graphql/schema/object.rb in graphql-1.8.5 vs lib/graphql/schema/object.rb in graphql-1.8.6

@@ -58,9 +58,13 @@
 
       class << self
         def implements(*new_interfaces)
           new_interfaces.each do |int|
             if int.is_a?(Module)
+              unless int.include?(GraphQL::Schema::Interface)
+                raise "#{int} cannot be implemented since it's not a GraphQL Interface. Use `include` for plain Ruby modules."
+              end
+
               # Include the methods here,
               # `.fields` will use the inheritance chain
               # to find inherited fields
               include(int)
             end