Testing window.location.href in React unit tests using Mocha, Karma

I have a simple react component where I have an onClick event which redirects to another page - the Google search engine (for testing purposes).

Here's the JSFiddle link for the React component - http://ift.tt/29sKJ5Z

describe('Events', function () {
    it('should have click event state', function (done) {
        var events = Events();
        ReactTestUtils.renderIntoDocument(events);
        ReactTestUtils.Simulate.click(events.refs.button.getDOMNode());
        //Test to see if the page redirects to correct url?
        done();
    });
});

How can I test that the browser was redirected to the correct url? Should I be mocking window.location.href? Or is there something else ?