tracked-built-ins array demo

controllers.application\.js

import Controller from '@ember/controller';
import { tracked } from 'tracked-built-ins';
import { action } from '@ember/object';

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

  woo = tracked([0, 1, 2, 3]);

  @action
  insertRandomly() {
    let targetIndex = Math.floor(this.woo.length * Math.random());
    this.woo.insertAt(targetIndex, Math.random());
  }
}

helpers.stringify\.js

import { helper } from '@ember/component/helper';

export default helper(function stringify(params/*, hash*/) {
  return JSON.stringify(params[0], null, 4);
});

templates.application\.hbs

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

<button type="button" {{on 'click' this.insertRandomly}}>Insert Randomly</button>

<br>

<pre><code>{{stringify this.woo}}</code></pre>


<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",
    "tracked-built-ins": "1.0.2"
  }
}