add basic example

app/controllers/application.js

@@ -0,0 +1,17 @@
+import Controller from '@ember/controller';
+import { action } from '@ember/object';
+// import { reject } from 'rsvp';
+
+export default class ApplicationController extends Controller {
+
+  // @action
+  // doSomethingAsyncThatFails() {
+  //   return reject('failed');
+  // }
+
+  @action
+  async doSomethingAsyncThatFails() {
+    throw new Error('failed')
+  }
+
+}

app/routes/application.js

@@ -0,0 +1,4 @@
+import Route from '@ember/routing/route';
+
+export default class ApplicationRoute extends Route {
+}

app/templates/application.hbs

@@ -1,5 +1 @@
-{{!-- The following component displays Ember's default welcome message. --}}
-<WelcomePage />
-{{!-- Feel free to remove this! --}}
-
-{{outlet}}
+<button type="button" {{on "click" this.doSomethingAsyncThatFails}}>Do something async that fails</button>

tests/acceptance/application-test.js

@@ -0,0 +1,29 @@
+import { module, test } from 'qunit';
+import { visit, click } from '@ember/test-helpers';
+import { setupApplicationTest } from 'ember-qunit';
+import { setupOnerror, resetOnerror } from '@ember/test-helpers';
+
+module('Acceptance | application', function(hooks) {
+  setupApplicationTest(hooks);
+
+  test('visiting /', async function(assert) {
+    assert.expect(0);
+
+    // We know the application will error in this test, but that's OK,
+    // we want to specifically test the error state so that the test
+    // doesn't fail.
+    setupOnerror(error => {
+      if (error === 'failed') {
+        return;
+      }
+
+      throw error;
+    });
+
+    await visit('/');
+
+    await click('button');
+
+    resetOnerror();
+  });
+});

tests/unit/controllers/application-test.js

@@ -0,0 +1,12 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Controller | application', function(hooks) {
+  setupTest(hooks);
+
+  // TODO: Replace this with your real tests.
+  test('it exists', function(assert) {
+    let controller = this.owner.lookup('controller:application');
+    assert.ok(controller);
+  });
+});

tests/unit/routes/application-test.js

@@ -0,0 +1,11 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Route | application', function(hooks) {
+  setupTest(hooks);
+
+  test('it exists', function(assert) {
+    let route = this.owner.lookup('route:application');
+    assert.ok(route);
+  });
+});