Rule Definition
An empty "error/fail" block defeats the purpose of http error management. When an exception occurs, nothing happens and the program fails for an unknown reason. The application can be in an unknown state that will affect subsequent processing. Since the reason for the issue (the exception type and potential embedded message) are ignored, it will require more time to fix the issue.

Remediation
The error must be handled correctly.

Violation Code Sample

$.ajax({
   type: 'POST',
   url: '_auth/login',
   success: function(res, status, xhr) { window.location.reload(); },
   error: function(xhr, status, err) {
   // EMPTY so there is a VIOLATION
   },
   complete: function(xhr, status, err) {
   }
});

-------------------------------------------
$.ajax({
   type: 'POST',
   url: '_auth/login'
})
.done(successHandler)
.fail(function() {
   // EMPTY so there is a VIOLATION
})
.always();

Fixed Code Sample

$.ajax({
   type: 'POST',
   url: '_auth/login',
   success: function(res, status, xhr) { window.location.reload(); },
   error: function(xhr, status, err) {
      alert("An error occured: "+data); // Error has been presented to the user, NO VIOLATION 
   },
   complete: function(xhr, status, err) {
   }
});

-------------------------------------------
$.ajax({
   type: 'POST',
   url: '_auth/login'
})
.done(successHandler)
.fail(function() {
      alert("An error occured: "+data); // Error has been presented to the user, NO VIOLATION 
})
.always();

OMG CISQ http://cwe.mitre.org/data/definitions/391.html