Ember DRF adapter unit-test failure

application-test.js

import {
  moduleFor,
  test
} from 'ember-qunit';

moduleFor('adapter:application', 'ApplicationAdapter', {
  // Specify the other units that are required for this test.
  // needs: ['serializer:foo']
});

// Replace this with your real tests.
test('it exists', function(assert) {
  var adapter = this.subject();
  assert.ok(adapter);
});

ApplicationAdapter.js

import DRFAdapter from './drf';
import ENV from '../config/environment'

export default DRFAdapter.extend({
    host: ENV.API_HOST,
    namespace: ENV.API_NAMESPACE
});

environment.js

'use strict';

//values needed for testing only
module.exports = function(environment, appConfig) {
   var ENV = {
        modulePrefix: 'merchant',
        environment: environment,
        baseURL: '/',
        locationType: 'auto',
        EmberENV: {
            FEATURES: {
                // Here you can enable experimental features on an ember canary build
                // e.g. 'with-controller': true
            }
        },

        APP: {
            API_NAMESPACE : 'api',
            API_HOST : 'http://localhost:4200'
          // Here you can pass flags/options to your application instance
          // when it is created
        }
    };
    
    return ENV;
};