NodeClass.js

// graphql definition for User
type User implements Node {
  _id: ID
  name: String
  friends: [User] 
}
// implement
import { Users} from '/imports/models'
class Node {
  constructor(node) {
    _.extend(this, node)
  }
}

class User extends Node {
  friends() {
    const users = Users.find({ _id: { $in: this.friendIds } }).fetch();
    return users.map(user => new UserNode(user));
  } 
}