George Washington - A user testing test

georgeWashington.js

/**
 * This script is a test to see whether the people who are supposed to be user testing your site are actually doing 
 * anything. It injects a piece of red text with content of George Washington somewhere in the document. It's designed
 * to look for lowest hanging HTML dom nodes in the DOM tree (no children elements) that are visible (offsetParent is not null).
 */
(function () {
  var nodes = Array.prototype.filter.call(document.querySelectorAll('div, p, span, blockquote, code, a, td'), function (node) {
    return !(node.children && node.children.length) && node.offsetParent !== null;
  });
  if (nodes.length) {
    nodes[Math.floor(Math.random() * nodes.length)].innerHTML += '<span style=\'color:red;font-weight:bold;\'>George Washington</span>';
  }
})();