Fix object returned from GraphQL-js to work without intermediate serialization

utils.ts

import { mergeWith } from "lodash";

export function nullPrototypeFix(object: Object): Object {
  return mergeWith({}, object, (a: any, b: any) => {
    if (b === null || typeof b === "undefined") {
      return b;
    } else if (typeof b.toJSON == "function") {
      return b.toJSON();
    }
  });
}