each-in and tracked properties

controllers.application\.js

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

class Me {
  tired = null
  hungry = null

  constructor(me) {
    this.tired = me.tired;
    this.hungry = me.hungry;
  }
}

class TrackedMe {
  @tracked tired = null
  @tracked hungry = null

  constructor(me) {
    this.tired = me.tired;
    this.hungry = me.hungry;
  }
}

export default class ApplicationController extends Controller {
  @tracked me = {
	  tired: 'yes',
    hungry: 'sure',
  }

  @tracked alsoMe = new Me({
	  tired: 'yes',
    hungry: 'sure',
  })

  @tracked trackedMe = new TrackedMe({
	  tired: 'yes',
    hungry: 'sure',
  })

  @action
  justKidding() {
    // won't trigger a new render, as expected
    this.me.tired = 'no';
    this.me.hungry = 'no';
    
    // won't trigger a new render, as expected
    this.alsoMe.tired = 'no';
    this.alsoMe.hungry = 'no';
    
    // will trigger a new render, as expected
    this.trackedMe.tired = 'no';
    this.trackedMe.hungry = 'no';
  }
}

templates.application\.hbs

WILL NOT re-render, as expected
<br>
{{#each-in this.me as |key value|}}
  <strong>{{key}}</strong>? <em>{{value}}</em>
  <br>
{{/each-in}}
<br>
WILL NOT re-render, as expected
<br>
{{#each-in this.alsoMe as |key value|}}
  <strong>{{key}}</strong>? <em>{{value}}</em>
  <br>
{{/each-in}}
<br>
FAILED! `each-in` does not work with tracked properties
<br>
{{#each-in this.trackedMe as |key value|}}
  <strong>{{key}}</strong>? <em>{{value}}</em>
  <br>
{{/each-in}}
<br>
WILL re-render, as expected
<br>
<strong>tired</strong>? <em>{{this.trackedMe.tired}}</em>
<br>
<strong>hungry</strong>? <em>{{this.trackedMe.hungry}}</em>
<br>
<br>
<button {{on "click" this.justKidding}}>
  Really?
</button>

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"
  }
}