JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="comment"></textarea>

JavaScript

$('#comment').keypress(function(event) {
    if (event.which == 13) {
        event.preventDefault();
    }
});

$('#comment').keyup(function() {
    var txt = $('#comment').val();
    $('#comment').val(txt.replace(/[\n\r]+/g, " "));

});