New Twiddle

controllers.application\.js

import Controller from '@ember/controller';
import { Promise as RSVPromise } from 'rsvp';

const a = new Promise(() => {});
const b = new RSVPromise(() => {});

function isFn(val) {
  return typeof value === 'function' && typeof value.nodeType !== 'number'
}

function isPromiseContract(value) {
  return isFn(value?.then) && isFn(value?.catch) && isFn(value?.finally);
}

function isPromise(value) {
  return Promise.resolve(value) === value;
}

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
	rsvpIsPromiseContract = isPromiseContract(b);
  rsvpIsPromise = isPromise(b);

  nativeIsPromiseContract = isPromiseContract(a);
  nativeIsPromise = isPromise(a);
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
RSVP Contract: {{this.rsvpIsPromiseContract}}<br>
RSVP is Promise: {{this.rsvpIsPromise}}<br>
Native Contract: {{this.nativeIsPromiseContract}}<br>
Native is Promise: {{this.nativeIsPromise}}<br>
<br>
{{outlet}}
<br>
<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"
  }
}