ng-class not evaluating during unit test

In attempting to unit test my custom directive, I ran into an issue trying to find an element with a dynamic class applied to it, based on an expression within an ng-class directive. It seems to me that the expression is just not evaluating at all. Is this possible to test? And if so, what am I doing wrong or missing?

The first unit test passes fine, the second is where the issue lies.

The tests:

beforeEach(inject(function ($rootScope, $compile) {

    scope = $rootScope.$new();

    element = '<tp-navigation-bar></tp-navigation-bar>';

    scope.currentPage = 'reports';
    scope.contactName = 'Test Name';
    scope.isLoggedIn = true;

    element = $compile(element)(scope);
    scope.$digest();
}));

it("should contain a dropdown with the contact name as the title", function () {

    expect(element.find('.dropdown-toggle span:nth-child(2)').text()).toEqual('Test Name');
});

it("should have reports set as the active page", function () {

    expect(element.find('li .active').text()).toEqual('Reports');
});

The template:

<ul class="nav navbar-nav navbar-right" ng-show="isLoggedIn">
    <li ng-class="{active:currentPage === 'mainDashboard'}">
       Home
    </li>
    <li ng-class="{active:currentPage === 'requests'}">
       Requests
    </li>
    <li ng-class="{active:currentPage === 'reports'}">
       Reports
    </li>
</ul>