Class Renderer

Returns a promise which will resolve when rendering has completed. In this context, rendering is completed when all auto-tracked state that is consumed in the template (including any tracked state in models, services, etc. that are then used in a template) has been updated in the DOM.

For example, in a test you might want to update some tracked state and then run some assertions after rendering has completed. You could use await settled() in that location, but in some contexts you don't want to wait for full settledness (which includes test waiters, pending AJAX/fetch, run loops, etc) but instead only want to know when that updated value has been rendered in the DOM. THAT is what await renderSettled() is perfect for.

import { renderSettled } from '@ember/renderer';
import { render } from '@ember/test-helpers';
import { tracked } from '@glimmer/tracking';
import { hbs } from 'ember-cli-htmlbars';
import { setupRenderingTest } from 'my-app/tests/helpers';
import { module, test } from 'qunit';

module('Integration | Component | profile-card', function (hooks) {
  setupRenderingTest(hooks);

  test("it renders the person's name", async function (assert) {
    class Person {
      @tracked name = '';
    }

    this.person = new Person();
    this.person.name = 'John';

    await render(hbs`
      <ProfileCard @name={{this.person.name}} />
    `);

    assert.dom().hasText('John');

    this.person.name = 'Jane';

    await renderSettled(); // Wait until rendering has completed.

    assert.dom().hasText('Jane');
  });
});