New Twiddle

controllers.application\.js

import Controller from '@ember/controller';
import { computed, set } from '@ember/object';
import { later } from '@ember/runloop';
import { tracked } from '@glimmer/tracking';

export default class ApplicationController extends Controller {
	@tracked _cart = null;
  
	@computed('cart')
	get outputDude() {
    console.log(`• get outputDude(${JSON.stringify(this.cart)})`);
    
    return JSON.stringify(this.cart);
  }

	@computed('_cart')
	get cart() {
    console.log(`• get cart(${JSON.stringify(this._cart)})`)
    
    if (!this._cart) {
    	this._initDefaultTemps();
	  }
    
    return this._cart;
  }
	
	set cart(vals) {
    console.log(`• set cart(${JSON.stringify(vals)})`);
    this._cart = vals;
    return this._cart;
  }


	_initDefaultTemps() {
    // set(this, 'cart', { a: 'A', b: 'B' });
		this.cart = { a: 'A', b: 'B' };

    // later(this, '_setXYZ', 'XYZ', 1100);
    this._setXYZ('XYZ');
  }
 
	_setXYZ(val) {
    console.log(`• _setXYZ(${val})`);
    this.cart.xyz = val;
  }
}

templates.application\.hbs

<h1>Ember Twiddle</h1>
<br>

{{#each-in cart as |key value|}}
	{{key}}: {{value}}<br>
{{/each-in}}

<br>
outputDude:
<br>
{{outputDude}}
<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"
  }
}