Ember layered async model RSVP hash

routes_retail.js

  model(params){
    var allProds = this.store.findAll('product'),
        brandsPromise = allProds.then(allProducts => {
          var allBrands  = allProducts.map( aProd => aProd.get('vendor')),
          filteredBrandPromise = new Promise(function (resolve, reject){
            resolve( Array.from(new Set(allBrands)).sort());
            reject();
          });
          return filteredBrandPromise;
        }
      );

    return Ember.RSVP.hash({
      allCategories: this.store.findAll('product-category'),
      allProducts: allProds,
      selectedFilterCategory: (params.categoryId) ? this.store.findRecord('product-category', params.categoryId) : null,
      selectedFilterBrand: (params.brand) ? params.brand : null,
      allBrands: brandsPromise
    });
  },