Unit test in jasmine for elements window.history.forward

Question

I need to cover this line with unit tests in angular, what would I need to cover this

app.component.ts

  cantReturn() {
    window.onpopstate =  ()=> window.history.forward()
  }

app.component.spec.ts

 it('test function1', function () {
   const spy = spyOn(window.history, 'forward' );
    component.cantReturn()
    expect(spy).toHaveBeenCalled();
  });