JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id='a' style="width:100%;height:300px;"></textarea>

JavaScript

var textArea = document.getElementById('a');
var tempo = function (i) {
    setTimeout(function () {
        textArea.value += 'Mensagem ' + i + '\n';
        textArea.scrollTop = textArea.scrollHeight;
    }, 100 * i);

}
for (var i = 0; i < 50; i++) {
    tempo(i);
}