JSFiddle - React, Tailwind, and code Playground

HTML

<button type="sumit" class="btn xs default" data-show="dialog">
    <i class="ellipsis-v">x</i>
    <span>fooo</span>
</button>
<button type="sumit" class="btn xs default" data-show="dialog">
    <i class="ellipsis-v">x</i>
    <span>fooo</span>
</button>

CSS

.ellipsis-v{
background-color:green;    
    width:10px;
    height:10px;
}
span{
  background-color:yellow;    
}

JavaScript

function fufu(e){
 console.log(e.target,this);
}
var b=document.getElementsByClassName('btn'),l=b.length;
while(l--){
 b[l].addEventListener('click',fufu,false);
}