New Twiddle

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { tracked } from '@glimmer/tracking';

export default class ApplicationController extends Controller {
  @tracked seededValue
  
  @action onStepperItemChange() {
    console.dir(arguments)
  }

























	init() {
    super.init()
    
    const script = document.createElement('script')
    script.type = 'module'
    script.src = 'https://unpkg.com/@esri/calcite-components@next/dist/calcite/calcite.esm.js'
    document.head.appendChild(script)
    
    const link = document.createElement('link')
    link.rel = 'stylesheet'
    link.href = 'https://unpkg.com/@esri/calcite-components@next/dist/calcite/calcite.css'
    document.head.appendChild(link)
  }
}

templates.application\.hbs

<calcite-stepper {{on 'calciteInternalStepperItemChange' this.onStepperItemChange}}>
	<calcite-stepper-item active item-title="Title one">
  	Body one
  </calcite-stepper-item>
	<calcite-stepper-item item-title="Title two">
  	Body two
  </calcite-stepper-item>
</calcite-stepper>

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/render-modifiers": "2.0.2",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}