fail.js

export default Ember.Route.extend({
  afterModel: function() {
    localStorage.clear();
    var self = this;
    var id = 1;

    // Run 2 times
    for (var n = 2; n > 0; n--) {
      self.store.findRecord("user", id).then(function(user) {
        console.info("User already exists with id ", user.get("id"));
      }, function() {
        var user = self.store.createRecord("user", {
          name: "Joe",
          id: id
        });

        console.info("User was created with id", user.id);
      })
    }
  }
});