title: Angular 2 Testing - Async function call - when to use
body: <p>When do you use the async function in the <strong>TestBed</strong> when testing in Angular 2?</p>
  
  <p>When do you use this?</p>
  
  <pre><code> beforeEach(() =&gt; {
          TestBed.configureTestingModule({
              declarations: [MyModule],
              schemas: [NO_ERRORS_SCHEMA],
          });
      });
  </code></pre>
  
  <p>And when do you use this?</p>
  
  <pre><code>beforeEach(async(() =&gt; {
      TestBed.configureTestingModule({
          declarations: [MyModule],
          schemas: [NO_ERRORS_SCHEMA],
      });
  }));
  </code></pre>
  
  <p>Can anyone enlighten me on this ?</p>