Send an http request and try to show what is the cookie received.
Open your console.
<script type="text/javascript">
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
  if(xhr.readyState == 4 && xhr.status == 200){
    console.log('Get xhr result', xhr.responseText);
    console.log('document.cookie', document.cookie);
    console.log("docCookies.getItem('test')", docCookies.getItem('test'));
  }
}
xhr.open('GET', 'getcookie.php', true);
xhr.send(null);

 
var docCookies = {
  getItem: function (sKey) {
		if (!sKey || !this.hasItem(sKey)) { return null; }
			return unescape(document.cookie.replace(new RegExp("(?:^|.*;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=\\s*((?:[^;](?!;))*[^;]?).*"), "$1"));
  },
	hasItem: function (sKey) {
		return (new RegExp("(?:^|;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=")).test(document.cookie);
	}
}
</script>