crbug.com/241367

by int32_t

HTML

<form id="myForm">
    <input id="test1" value="123" pattern="[a-zA-Z]{2,16}">
    <input id="test2" required >
    <input type="submit">
</form>

<hr>
<pre id="console"></pre>

JavaScript

function $(id) { return document.getElementById(id); }
function log(mes) {
    $('console').textContent += mes + '\n';
}

document.addEventListener('DOMContentLoaded', function(event) {
    log('test1: valid=' + $('test1').validity.valid);
    log('test2: valid=' + $('test2').validity.valid);
}, false);