article model favorited

//...

// return the data of our article
ArticleSchema.methods.toJSONFor = function(user) {
  return {
    slug: this.slug,
    title: this.title,
    description: this.description,
    body: this.body,
    createdAt: this.createdAt,
    updatedAt: this.updatedAt,
    tagList: this.tagList,
    favorited: user ? user.isFavorite(this._id) : false,
    favoritesCount: this.favoritesCount,
    author: this.author.toProfileJSONFor(user)
  };
};

///...