script-performance-test.js

var testReplies  = 10000,
testCode = function() {
  /* code to test */
  //$(this) is #actionBox, use it as your container
  //#actionBox that will be removed after test

},
actionBoxConfigure = function(){
  /* put elements into actionBox here */
  //var i=100;
  //while(i-- > 0)
  //  $(this).append('<div class="sth">');
  
};

var testFunction = function() {
  var tmpReplies = testReplies,
      actionBox = jQuery('<div id="actionBox" style="position:absolute;top:-9999px"></div>').appendTo(document.body);
  
  actionBoxConfigure.call(actionBox[0]);
  
  var timeStart = new Date().getTime();
  while(tmpReplies-- > 0)
    testCode.call(actionBox[0]);
  var timeEnd = new Date().getTime();

  actionBox.remove()
  
  /* OUTPUT: */
  var getDate = function() {
    var date = new Date();
    return date.getFullYear() + '-' + ('0' + (date.getMonth() + 1)).slice(-2) +'-'+('0'+date.getDate()).slice(-2)+ ' ' + ('0'+date.getHours()).slice(-2) + ':' + ('0'+date.getMinutes()).slice(-2) + ':' + ('0'+date.getSeconds()).slice(-2);
  };
  
  return getDate() + ': '
         + testCode.toSource().length + ' bytes of code, '
         + testReplies + ' replies in '
         + ((timeEnd - timeStart)/1000) + ' seconds';
};

if(window.jQuery) {
    testFunction();
} else {
  var s = document.createElement('script');
  s.onerror = function() {
    console.log("Can't load jQuery");
  };
  s.onload = function() {
    console.log(testFunction());
  };
  s.setAttribute('src','http://code.jquery.com/jquery-latest.min.js');
  document.getElementsByTagName('head')[0].appendChild(s);
  'Loading jQuery...';
}