<body><div id="content">
    <a id="link" href="foo" class="ok">OK</a>
    <p id="para-empty" class="ok empty">
      <span id="para-empty-child"></span>
    </p>
    <p id="para"> And</p>
    <!--comment-->
  </div>
</body>

<script src="../testing.js"></script>
<script>
function trimAndReplace(str) {
  str = str.replace(/(\r\n|\n|\r)/gm,'');
  str = str.replace(/\s+/g, ' ');
  str = str.trim();
  return str;
}

let content = $('#content');
let link = $('#link');
let first_child = content.firstChild.nextSi