JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="testerText" />

JavaScript

$(document).ready(
    function()
    {
        var delay = (function(){
          var timer = 0;
          return function(callback, ms){
            clearTimeout (timer);
            timer = setTimeout(callback, ms);
          };
        })();

       $("#testerText").keyup(
           function()
           {
                delay(function()
                    {
 $("#testerText").val($("#testerText").val().toUpperCase());
                    }, 1000);
           });
    });