JSFiddle - React, Tailwind, and code Playground

HTML

<h1> test page </h1>
<pre id="xxx"></pre>

JavaScript

var messages = [];
function log(msg) {
    messages.push(msg);
    $("#xxx").text(messages.join("\n"));
}

$(function() {

    $(document).ajaxStart(function() { log('ajax start'); });
    $(document).ajaxSend(function() { log('ajax sent'); });
    $(document).ajaxStop(function() { log('ajax stop'); });

    log('init');
    $.ajax({
        type:     "POST",
        url:      '/echo/json/',
        data:     { 
            json: [''], 
            delay: 35
        },
        complete: function () { log('complete'); },
        success:  function (data) { log('success:'+data); },
        error:    function (event, jqXHR, ajaxSettings, thrownError) {
            log('error:');
            log("\t" + event);
            log("\t" + jqXHR);
            log("\t" + ajaxSettings);
            log("\t" + thrownError);
        },
    });
});