portainer/app/azure/services/subscriptionService.js

angular.module('portainer.azure')
.factory('SubscriptionService', ['$q', 'Subscription', function SubscriptionServiceFactory($q, Subscription) {
  'use strict';
  var service = {};

  service.subscriptions = function() {
    var deferred = $q.defer();

    Subscription.query({}).$promise
    .then(function success(data) {
      var subscriptions = data.value.map(function (item) {
        return new SubscriptionViewModel(item);
      });
      deferred.resolve(subscriptions);
    })
    .catch(function error(err) {
      deferred.reject({ msg: 'Unable to retrieve subscriptions', err: err });
    });

    return deferred.promise;
  };

  return service;
}]);