JSFiddle - React, Tailwind, and code Playground

JavaScript

function log(text) {
  $('<p>').text(text).appendTo('body');
}
log($.fn.jquery);

var deferred = $.Deferred();
var context = {};

deferred.then(function () {
  return $.Deferred().resolveWith(context);
}).done(function () {
  if (this === context) {
    log('This is context');
  } else {
    log('This is NOT context');
  }
});

deferred.resolve();