JSFiddle - React, Tailwind, and code Playground

by NekR

HTML

<!DOCTYPE html>
<html> 
<head> 
<title></title> 
<meta charset="utf-8">
<style>
html, body {width: 100%; height: 100%; padding: 0; margin: 0;}
</style>
</head> 
<body> 
<form method="get" action="" style="margin: 50px;">
<input type="text" placeholder="Test" required id="test">
<br><br>
<input type="submit" value="Submit">
</form>
<script>
var test = document.getElementById('test');
test.addEventListener('invalid', function(e){
        e.preventDefault();
        e.stopPropagation();
        alert('Вот так ;)')
}, false)
</script>
</body> 
</html>