JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <span>marco</span>
</div>

JavaScript

var c = document.getElementById('container');
c.__appendChild = c.appendChild;
c.appendChild = function(){
    alert('new item added');
    c.__appendChild.apply(c, arguments); 
};

$(document).ready(function(){
    $('#container').append('<span>polo</span>');
});