The to_h method of GraphQL::Pro::Defer::Deferral does not return any data when errors are present.
This seems to contradict the docs which say .to_h returns a hash with path:, data:, and/or errors: (tbf, the comment in the method signature is more clear/explicit: @return [Hash] with 'path:', either 'errors:' or 'data:', and 'label:', if given.)
It seems like it would be more useful to return both errors and data, and let the client code decide what to do with them.