change plain txt url into html link

linkify.html

<div id="test">
  http://google.com
</div>
<script>
  var txt = document.querySelector('body').innerHTML;
  var pattern = /(HTTP:\/\/|HTTPS:\/\/)([a-zA-Z0-9.\/&?_=!*,\(\)+-]+)/i;
  var replace = "<a href=\"$1$2\">$1$2</a>";
  var result = txt.replace(pattern , replace);
  document.querySelector('body').innerHTML = result;
</script>