JSFiddle - React, Tailwind, and code Playground

HTML

<div contenteditable="true">
    div
    <span>Test Span area</span>
    div
</div>

CSS

div {
    border: 1px solid red;
    padding: 5px;
}
span {
    background-color: #efefef;    
}

JavaScript

function detect(){
    if(document.selection){
        //IE
        alert(document.selection.createRange().parentElement().tagName);
    }else{
        // everyone else
        alert(window.getSelection().anchorNode.parentNode.tagName); 
    }
}

$(function(){
    $("div").keypress(function(){
        detect();
    });
});