js-fe-test-blog-async-test-case.js

$myapp.get = function (url, callback) {
    var requestListener = function () {
      if (httpRequest.readyState === XMLHttpRequest.DONE) {
        if (httpRequest.status === 200) {
          var response = JSON.parse(httpRequest.response);
          callback(response);
        } else {
          alert('There was a problem with the request');
        }
      }
    };

    var httpRequest = new XMLHttpRequest();
    httpRequest.addEventListener('load', requestListener);
    httpRequest.open('GET', url);
    httpRequest.send();
  };

  $myapp.getUser = function (id) {
    $myapp.get('/api/users?id=' + id, function (user) {
      var domElement = document.querySelector('#user-detail');
      if (user) {
        domElement.innerHTML = user.fname + ' ' + user.lname;
      }
    });
  };