JSFiddle - React, Tailwind, and code Playground

HTML

<button>TEST</button>

JavaScript

$(document).ready(function () {
    
    var longpress = false;
    var interv;

    $("button").on('mousedown', function () {
        startTime = new Date().getTime();
        var i = 0;
        interv = setInterval(function(){
            console.log(i++);
        }, 500);
    });

    $("button").on('mouseup', function () {
        clearInterval(interv);
    });
    
});