$ component install anthonyshort/css-emitter

$ npm install css-emitter-component

var css = require('css-emitter');
var el = document.querySelector('#box');
var animate = css(el);
// Bind
animate.bind(function(e){
  console.log('%s property changed on %s event', e.propertyName, e.type);
});
// Change height and width
setTimeout(function(){
  el.className = 'in';
}, 1000);

#box {
  width: 100px;
  height: 100px;
  transition: all 1s ease;
  -webkit-transition: all 1s ease;
  -moz-transition: all 1s ease;
  -o-transition: all 1s ease;
  background: black;
  display: block;
}
#box.in {
  width: 200px;
  height: 200px;
}