JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type="text" name="txt">
    <button name="btn">Check the text</button>
</form>

JavaScript

var $btn = $('[name="btn"]'),
    $txt = $('[name="txt"]');
$('form').on('click', $btn, function(e) {
    e.preventDefault();
    console.log($(':focus').length);
    if($txt.is(':focus')) {
        console.log('Input is focused. Handle the click');
    } else {
        console.log('Input is not focused');
    }
});
$txt.on('keydown', function() {
    console.log($(':focus').length);
});