Using window object in Angular 2

gistfile1.txt

// interface for Window
interface Window {
  // add some stuff here
}

let someMockWindowObject = {
  // add some mock functionality here
};

// for browser providers
provide(Window, { useValue: window });

// for node and testing
provide(Window, { useValue: someMockWindowObject })

// inject it
class Foo {
  constructor(private window: Window) {}
}

For reference and unit testing, here is what worked for me:
In my service (can be done in a component too):

  setUpBeforeunload(): void {
    window.addEventListener('beforeunload', this.closeConnection);
  }

In my spec (Jasmine testing):

    it('should set up window eventListener', () => {
      spyOn(window, 'addEventListener');
      service.setUpBeforeunload();
      expect(window.addEventListener).toHaveBeenCalledWith('beforeunload', service.closeConnection);
    });

And another test:

    it('should call closeConnection()', () => {
      spyOn(service, 'closeConnection');
      service.setUpBeforeunload();
      window.dispatchEvent(new Event('beforeunload'));
      expect(service.closeConnection).toHaveBeenCalled();
    });