Rule Definition
Ensure that each web service callback is going to be properly checked in order to make sure you will not miss any problem that occurred in your application and you will give the information to the user.

Remediation
Ensure the done, fail and/or always callbacks have been implemented

Violation Code Sample

var jqxhr = $.ajax( "example.php" )
 
// Perform other work here ...

Fixed Code Sample

var jqxhr = $.ajax( "example.php" )
  .done(function() {
    alert( "success" );
  })
  .fail(function() {
    alert( "error" );
  })
  .always(function() {
    alert( "complete" );
  });

// OR 
 
// Set another completion function for the request above
jqxhr.always(function() {
  alert( "second complete" );
});

http://api.jquery.com/jQuery.ajax/#options