promise proxy getter

controllers.application\.js

import Controller from '@ember/controller';
import ObjectProxy from '@ember/object/proxy';
import PromiseProxyMixin from '@ember/object/promise-proxy-mixin';
import { computed } from '@ember/object';
const PromiseProxyObject = ObjectProxy.extend(PromiseProxyMixin);

export function promiseObject(promise) {
  return PromiseProxyObject.create({ promise });
}

export default class ApplicationController extends Controller {
  proxy = promiseObject(new Promise(resolve => {
    setTimeout(resolve({
      name: 'Fred' 
    }), 2000);
  }));

  get displayName() {
    return `${this.proxy.get('name')}!`; 
  }
}

templates.application\.hbs

proxy: {{this.proxy.name}}<br>
getter {{this.displayName}}<br>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}