JSFiddle - React, Tailwind, and code Playground

HTML

<p id="hello">Fail!</p>

JavaScript

$(document).ready(function () {
    $('#hello').hover(function () {
        $(this).text("It works!");
    }, function () {
        $(this).text("should not be seen in testcase");
    });
    
    $('#hello').mouseover();

});

/* Analysis + Fix by Henrik Hjelte (henrik.hjelte at gmail)

This works with jquery up to and including 1.5, starts breaking with 1.5.1
The problem is on line 2788 of dist/jquery.js
          Modified                jquery.js
2788      
-        if ( parent !== document && !parent.parentNode ) {
+        if ( parent !== document && (parent && !parent.parentNode )) {

The problem is that since event.relatedTarget is optional,
the check for parent.parentNode might break if event is null/undefined.

var withinElement = function( event ) {
    // Check if mouse(over|out) are still within the same parent element
    var parent = event.relatedTarget;

    // Firefox sometimes assigns relatedTarget a XUL element
    // which we cannot access the parentNode property of
    try {

        // Chrome does something similar, the parentNode property
        // can be accessed but is null.
        if ( parent !== document && !parent.parentNode ) { // THIS FAILS
        if ( parent !== document && (parent && !parent.parentNode )) { // THIS WORKS            return;
        }
        // Traverse up the tree
        while ( parent && parent !== this ) {
            parent = parent.parentNode;
        }

        if ( parent !== this ) {
            // set the correct event type
            event.type = event.data;

            // handle event if we actually just moused on to a non sub-element
            jQuery.event.handle.apply( this, arguments );
        }

    // assuming we've left the element since we most likely mousedover a xul element
    } catch(e) { }
},*/