New Twiddle

components.my-component\.js

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';

export default class extends Component {
  constructor() {
    super(...arguments);
    this.eventuallyUpdate();
  }
  
  @tracked personOne = "I";
	@tracked personTwo = "You";

	eventuallyUpdate() {
    setInterval(() => {
      this.personTwo = "Y'all";
      
      console.log({
        yup,
        nopeButInTemplate,
        nope
      })
    }, 3000)
  }

  get yup() {
    return `${this.personOne} say hi to ${this.personTwo}`;
  }

	get nopeButInTemplate() {
    return `${this.personOne} say bye to ${this.personTwo}`;
  }
  
  get nope() {
    return `${this.personOne} say bye to ${this.personTwo}`;
  }
}

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

styles.app\.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.message {
  padding: 32px;
  margin: 16px 0;
  border-radius: 8px;
  background: #c5c5c5;
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
<br>
<MyComponent />
<br>
<br>

templates.components.my-component\.hbs

<div class="message">
{{yup}}
</div>

<div class="message">
{{nopeButInTemplate}}
</div>

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"
  }
}