enabled_previews.rb in graphql-preview-0.0.7

- old
+ new

@@ -7,13 +7,15 @@
         unless previews.is_a?(Array)
           raise ArgumentError, "Expected `enabled_previews` to be an array, but it was `#{previews.class}`"
         end
 
         previews.each do |preview|
-          unless preview.ancestors.any? { |ancestor| ancestor == GraphQLPreview::SchemaModification }
-            raise ArgumentError, "One of your `enabled_previews` items does not descend from `GraphQLPreview::SchemaModification`"
+          unless preview < GraphQLPreview::SchemaModification
+            raise ArgumentError, "Preview #{preview} must inherit from `GraphQLPreview::SchemaModification`"
           end
         end
+
+        previews.each { |preview| preview.apply_to_schema(self) }
 
         @enabled_previews = previews
       end
 
       def enabled_previews=(previews)