Polymorphic association doesn't use model_name

I have the following (simplified) setup:

class User < ActiveRecord::Base;
class Member < ActiveRecord::Base;

class MemberResource < JSONAPI::Resource
  model_name 'User'
end

class BookResource < JSONAPI::Resource
   has_one :author, polymorphic: true  # type is 'Member' here
end

class AuthorResource < JSONAPI::Resource; end

When I tried to request GET /books/:book_id/author JR will load Member from members table and not users as it's described with model_name.

Would say it's a bug?

I know that my use case is a little bit complex, but in that simplified example we decide to show User as Member in the API (we have different model names).

Beginnen Sie damit, den Pfad GET /books/:book_id/author für die polymorphe author-Association von BookResource nachzuverfolgen und ihre Typauflösung mit dem model_name 'User' von MemberResource zu vergleichen. Reproduzieren Sie das Beispiel mit User, Member, MemberResource und BookResource. Überprüfen Sie anschließend, dass die Association zu users statt zu members aufgelöst wird, während die API-Ressourcennamen erhalten bleiben.