setting in integration test

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  translatedVal: Ember.computed('someVal', function () {
    return this.get('someVal') + ' is awesome';
  })
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
{{input type="text" value=appName}}

<h2>my-component</h2>
{{my-component someVal=appName}}
<br>
<br>
{{outlet}}
<br>
<br>

templates.components.my-component.hbs

<dt>Some Val</dt>
<dd class="reflected-val">{{someVal}}</dd>
<dt>My Val</dt>
<dd class="computed-val">{{translatedVal}}</dd>

{{yield}}

tests.helpers.resolver.js

import Resolver from '../../resolver';
import config from '../../config/environment';

const resolver = Resolver.create();

resolver.namespace = {
  modulePrefix: config.modulePrefix,
  podModulePrefix: config.podModulePrefix
};

export default resolver;

tests.integration.components.my-component-test.js

import { moduleForComponent, test } from 'ember-qunit';
import hbs from 'htmlbars-inline-precompile';

moduleForComponent('my-component', 'reflected and computed vales update correctly', {
  integration: true
});

test('it renders', function(assert) {
  assert.expect(4)

  this.set('appName', 'ember twiddle');
  this.render(hbs`{{my-component someVal=appName}}`);

  assert.equal(this.$('.reflected-val').text().trim(), 'ember twiddle', 'init reflected val found');
  assert.equal(this.$('.computed-val').text().trim(), 'ember twiddle is awesome', 'init computed val found');

  this.set('appName', 'your mom');
  
  assert.equal(this.$('.reflected-val').text().trim(), 'your mom', 'init reflected val found');
  assert.equal(this.$('.computed-val').text().trim(), 'your mom is awesome', 'init computed val found');
});

tests.test-helper.js

import resolver from './helpers/resolver';
import {
  setResolver
} from 'ember-qunit';
import { start } from 'ember-cli-qunit';

setResolver(resolver);
start();

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": true
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}