JSFiddle - React, Tailwind, and code Playground

HTML

<p id="message" />
<p id="result" />

JavaScript

"use strict";
function sayHello(person)
{
    message = "Hello, " + person;
    $("#message").text(message);
}

function sayHelloShouldNotAddToGlobalScope(globalObject)
{
    var initialGlobalCount = Object.keys(globalObject).length;
    sayHello("@ardalis");
    var endGlobalCount = Object.keys(globalObject).length;
    if(initialGlobalCount == endGlobalCount) {
        $("#result").text("Success!");
    } else {
        $("#result").text("Failed - Initial Count: " + 
                             initialGlobalCount + 
                              " End Count: " +
                             endGlobalCount);
    }
}

$(document).ready(function() {
    // run test
    sayHelloShouldNotAddToGlobalScope(window);    
});