JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
  <p>var foo = getUser(1);</p>
  <p>var bar = getUser(2);</p>
  <p>var baz = getUser(3);</p>
  <button id="run">Run</button>
  <button id="open">Open</button>
</body>
</html>

JavaScript

var run = document.getElementById("run");
var open = document.getElementById("open");

run.addEventListener("click", function() {
	var end = Date.now() + 2000;
  
  console.log("Running: getUser(1)");
  
  while(Date.now() < end) {}
  
  end = Date.now() + 2000;
  
  console.log("Running: getUser(2)");
  
  while(Date.now() < end) {}
  
  end = Date.now() + 2000;
  
  console.log("Running: getUser(3)");
  
  while(Date.now() < end) {}
  
  alert("Finish");
});

open.addEventListener("click", function() {
  alert("Helo");
});