JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button"  value="button" id="btn"/>

JavaScript

var eleBtn = document.getElementById('btn');

window.onerror = function(e) {
    console.log(e);
}
eleBtn.addEventListener('click', function() {
    eleBtn.focus();
});

eleBtn.addEventListener('blur', function() {
    console.log('blur');
});