JSFiddle - React, Tailwind, and code Playground

HTML

<div id="x" data-x="1"></div>
<div id="result"></div>

JavaScript

$(function() {
    var result = 'initial: ' + $('#x').data('x');
    $('#x').attr('data-x', 2);
    result += '<br/>reset: ' + $('#x').data('x');
    result += '<br/>expected: ' + $('#x').attr('data-x');
    $('#result').html(result);
});