Glimmer Coversion

components.foo\.js

import Component from '@glimmer/component';
import { action, computed, set } from '@ember/object';

export default class extends Component {
  prop1 = 0;

  @computed('prop1')
  get cp() {
    return this.prop1 * 1000;
  }

  @action
  update() {
    const newVal = this.prop1 + 1;
    console.log(newVal)
    set(this, 'prop1', newVal)
  }
}

controllers.application\.js

import Controller from '@ember/controller';

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

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<p>prop1 is the underlying value, and clicking on the button calls <code>Ember.set</code> to update it. The <code>cp</code> is a computed property that relies on the dependent key <code>prop1</code>. If we remove the dependent key, <code>cp</code> will stop updating when <code>prop1</code> changes.</p>

<p>Currently, the code "works". To see it break, open <code>app/components/foo.js</code> and comment out the <code>@computed</code> decorator.</p>

<Foo />

templates.components.foo\.hbs

<button {{on "click" this.update}}>update</button>
<table>
<tr><td>prop1</td><td>{{this.prop1}}</td></tr>
<tr><td>cp</td><td>{{this.cp}}</td></tr>
</table>

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"
  }
}