title: Unit test on angular
body: <p>Currently I'm working on Angular unit test with jasmine framework. Still couldn't figure out how to add unit test to below code snippets.</p>
  <p>Any ideas on that ?</p>
  <pre><code>ngOnInit() {
      document.body.scrollTop = 0;
      window.scrollTo(0, 0);
  }
  </code></pre>