JSFiddle - React, Tailwind, and code Playground

HTML

<a href="http://www.google.nl">test</a>

JavaScript

var userClicked = false;
$( "body" ).delegate( "a", "click", function() {
    userClicked = true;
});

window.onbeforeunload = function() {
    if (!userClicked) {
    	return "Your message";
    }
}