args / willDestroy

components.inner-component\.js

import Component from '@glimmer/component';

export default class extends Component {
  willDestroy() {
    console.log(this.args.data.name);
  }
}

components.outer-component\.js

import Component from '@glimmer/component';

export default class extends Component {
}

controllers.application\.js

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

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

router\.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

const Router = EmberRouter.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('a');
  this.route('b');
});

export default Router;

routes.a\.js

import Route from '@ember/routing/route';

export default Route.extend({
});

routes.application\.js

import Route from '@ember/routing/route';

class MyClass {
  _name = 'foo';

  get name() {
    return this._name;
  }
}

export default Route.extend({
  model() {
		return {
      data: new MyClass(),
    }
  }
});

routes.b\.js

import Route from '@ember/routing/route';

export default Route.extend({
});

templates.a\.hbs

<h2>A</h2>

<OuterComponent @data={{@model.data}} />

templates.application\.hbs

<h1>args are not available in willDestroy</h1>

<LinkTo @route="a">A</LinkTo>
<LinkTo @route="b">B</LinkTo>

{{outlet}}

templates.b\.hbs

<h2>B</h2>

<OuterComponent @data={{@model.data}} />

templates.components.inner-component\.hbs

<h3>InnerComponent</h3>

templates.components.outer-component\.hbs

<h2>OuterComponent</h2>

<InnerComponent @data={{@data}} />

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": "3.16.7",
    "ember-template-compiler": "3.16.7",
    "ember-testing": "3.16.7"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}