Very challenging directive - looking for guidance on how to unit test

I just realized that none of the tests I have written for my directive are working in a way that actually tests anything so I am rewriting them. Problem is I cant figure out a way to test the link functions.

If anyone has a suggestion I would really really appreciate it.

Thanks for looking

angular.module('pb.webSites.directives')
    .directive('pbOrganizationImagePicker', [ function () {

        return {
            restrict: "E",
            template: '<img data-ng-src="{{ imageSource }}" width="{{width}}" height="{{height}}" alt="Image Picker" class="img-rounded" />',
            scope: {
                fileId: '=pbFileId',
                defaultSrc: '@pbDefaultSrc',
                width: '@pbWidth',
                height: '@pbHeight'
            },
            controller: 'pbOrganizationImagePickerController',

            link: function (scope, element, attrs) {
                scope.$watch('defaultSrc', function (value) {
                    if (value !== undefined) {
                        scope.imageSource = value;
                    }
                });

                element.on('click', function () {
                    scope.pickImage().then(function (image) {
                        scope.imageSource = image.storageUrl;
                        scope.fileId = image.fileId;
                    }, function () {
                        console.log('Modal dismissed at: ' + new Date());
                    });
                });
            }
        };
    }]);