JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type='text' required />
    <button>check field validity</button>
</form>

JavaScript

(function() {
    var field = document.querySelector('input[type=text]');
    document.querySelector('button').addEventListener('click', function() {
        alert('Validates: '+field.willValidate);
        alert('Value missing: '+field.validity.valueMissing);
    }, false);
})();