custom.js

import Ember from "ember";
// This is an error. It should be 'ember-simple-auth/authenticators/base'
// Left to link to a github comment
import Base from 'ember-simple-auth/authorizers/base';

export default Base.extend({
  tokenEndpoint: '/api/user_sessions',
  authenticate: function(credentials) {
    var _this = this;
    return new Ember.RSVP.Promise(function(resolve, reject) {
      Ember.$.ajax({
        url: _this.tokenEndpoint,
        type: 'POST',
        data: JSON.stringify({
          username: credentials.identification,
          password: credentials.password
        }),
        contentType: 'application/json'
      }).then(function(response) {
        Ember.run(function() {
          resolve({ token: response.token });
        });
      }, function(xhr) {
        var response = JSON.parse(xhr.responseText);
        Ember.run(function() {
          reject(response.error);
        });
      });
    });
  },
  restore: function(data) {
    return new Ember.RSVP.Promise(function (resolve, reject) {
      resolve(data);
    });
  },
  invalidate: function(data) {
    return new Ember.RSVP.Promise(function (resolve, reject) {
      resolve();
    });
  },
  // on: function(event, callback) {
    // console.log('on');
    // console.log(callback.toString());
  // },
  // off: function() {}
});

Note, this is in error. It should be extended from "ember-simple-auth/authenticators/base" not "ember-simple-auth/authorizers/base".