New Twiddle

components.foo.bar.baz\.hbs

<div data-test-thing>Foo::Bar::Baz component</div>

components.foo.bar.baz\.js

import Component from '@glimmer/component';

export default class extends Component {
}

components.foo.bar\.hbs

<div data-test-thing>Foo::Bar component</div>

components.foo.bar\.js

import Component from '@glimmer/component';

export default class extends Component {
}

controllers.application\.js

import Controller from '@ember/controller';

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

templates.application\.hbs

<Foo::Bar::Baz />
<hr />
<Foo::Bar:Baz />

tests.integration.components.foo.bar.baz-test\.js

import { module, test } from 'qunit';
import { setupRenderingTest } from 'ember-qunit';
import { render, find } from '@ember/test-helpers';
import hbs from 'htmlbars-inline-precompile';

module('Integration | Component | foo/bar/baz', function(hooks) {
  setupRenderingTest(hooks);

  test('it renders', async function(assert) {
    await render(hbs`<Foo::Bar:Baz />`);
    assert.equal(find('[data-test-thing]').textContent.trim(), 'Foo::Bar::Baz component')
  });
});

tests.test-helper\.js

import Application from '../app';
import config from '../config/environment';
import { setApplication } from '@ember/test-helpers';
import { assign } from '@ember/polyfills';
import { start } from 'ember-qunit';

let attributes = {
  rootElement: '#test-root',
  autoboot: false
};
attributes = assign(attributes, config.APP);

let application = Application.create(attributes);
setApplication(application);

start();

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": true
  },
  "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"
  }
}