How to test keydown event in AngularJS with PhantomJS

I tried solution from here with this function

function jsKeydown(code){
  var oEvent = document.createEvent('KeyboardEvent');

  // Chromium Hack: filter this otherwise Safari will complain
  if( navigator.userAgent.toLowerCase().indexOf('chrome') > -1 ){
    Object.defineProperty(oEvent, 'keyCode', {
      get : function() {
        return this.keyCodeVal;
      }
    });     
    Object.defineProperty(oEvent, 'which', {
      get : function() {
        return this.keyCodeVal;
      }
    });
  }

  if (oEvent.initKeyboardEvent) {
    oEvent.initKeyboardEvent("keydown", true, true, document.defaultView, false, false, false, false, code, code);
  } else {
    oEvent.initKeyEvent("keydown", true, true, document.defaultView, false, false, false, false, code, 0);
  }

  oEvent.keyCodeVal = code;

  if (oEvent.keyCode !== code) {
    console.log("keyCode mismatch " + oEvent.keyCode + "(" + oEvent.which + ") -> "+ code);
  }

  document.getElementById("idToUseHere").dispatchEvent(oEvent);
}

// press DEL key
jsKeydown(46);

But this doesn't work, everitime I have oEvent.keyCode = 0

In unit tests keydown event are triggered, but I can't test if specific key a pressed.

Can anyone help me to resolve this or have a solution?