import Users from 'meteor/vulcan:users'; import { Utils } from 'meteor/vulcan:core'; Users.isSubscribedTo = (user, document) => { if (!user || !document) { // should return an error return false; } const { __typename, _id: itemId } = document; const documentType = Utils.capitalize(Utils.getCollectionNameFromTypename(__typename)); if (user.subscribedItems && user.subscribedItems[documentType]) { return !!user.subscribedItems[documentType].find(subscribedItems => subscribedItems.itemId === itemId); } else { return false; } };