JSFiddle - React, Tailwind, and code Playground

HTML

<span> </span>
<span></span>
<span>test</span>
<span><i>asd</i></span>

JavaScript

$.expr[":"]["no-children"] = function( elem ) {
    return !elem.firstChild || !$.trim(""+ elem.firstChild.nodeValue);
};
$("span:no-children").html("this was empty");