scroll vertical center div with overflow to clicked child div

var scrollToDiv = function(e){
  var divToScroll = document.getElementById('list');
  var childDivToScrollTo = e.target.closest('.list-item');
  var scrollDiff = childDivToScrollTo.offsetTop - divToScroll.scrollTop;
  var scrollDuration = Math.abs(scrollDiff / 3);
  var scrollIncrement = scrollDiff / scrollDuration;
  var scrollInt;
  function scroll() {
    if(scrollDuration <= 0 ) {
      clearInterval(scrollInt);
    } else {
      divToScroll.scrollTop+= scrollIncrement;
      scrollDuration --;
    }
  }
  scrollInt = setInterval(scroll, 1);
}