Mocking a directive with angularjs

I know there is $controllerProvider which can be used, to create controllers inside unit tests. I'm wondering however if there is a way to mock a directive inside of a unit test.

The background to this is, that I'm trying to mock(! not to create) a directive which is applying an async validator to ngModel. Perfect would be something like this:

beforeEach(function () {
   module('myMod', function($directiveProvider) {
      $directiveProvider.register('mockAsyncValidationDirective', function() {
          return {
              restrict: 'EA',
              require: 'ngModel'
              // ...
          }
      });
   });
});

Is there any way to do that?