3-17-willdestroyelement-bug

components.item\.js

import Component from '@ember/component';

export default class extends Component {
  willDestroyElement() {
    alert(`willDestroyElement called for ${this.item.name}`)
  }
}

controllers.application\.js

import Controller from '@ember/controller';
import {action} from '@ember/object';
import { A } from '@ember/array';

export default class ApplicationController extends Controller {
	items = A([
    { name: 'Item 1' },
    { name: 'Item 2' },
    { name: 'Item 3' }
  ])
	
  @action
  deleteItem(item) {
    this.items.removeObject(item);
  }

  @action
	addItem() {
    this.items.addObject({ name: 'New item' })
  }
}

templates.application\.hbs

<h2>Items</h2>	
{{#each items as |item|}}
  {{component "item" item=item delete=this.deleteItem}}
{{/each}}

<button {{action this.addItem}}>Add</button>

templates.components.item\.hbs

<div style="height:100px;width:100%;border:4px solid red; padding: 4px;">
	{{item.name}}
	<button {{action delete item}}>
    Delete me
  </button>
</div>

twiddle\.json

{
  "version": "0.17.0",
  "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/3.3.1/jquery.js",
    "ember": "3.17.0",
    "ember-template-compiler": "3.17.0",
    "ember-testing": "3.17.0"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}