JSFiddle - React, Tailwind, and code Playground

HTML

<div id="d">
    <p id="p">
    </p>
</div>

JavaScript

var d = document.getElementById("d");
var p = document.getElementById("p");

d.addEventListener ("DOMNodeInserted", function(ev) {
    if (ev.relatedNode == d) {
        alert("element inserted into div");
    }
    else if (ev.relatedNode == p) {
        alert("element inserted into p");
    }
});

var span = document.createElement("span");
d.appendChild(span);
p.appendChild(span);