How to test directives in ionic 2

I am using navPush directive for pushing a new page into the ionic view.

  <ion-card [navPush]="showHuntPage"  >

I am not sure how I can test if navPush component is set to showHuntPage in unit testing. I tried this

 let card: HTMLElement = fixture.debugElement.query(By.css('ion-card')).nativeElement;
 console.log(card.attributes.getNamedItem('navPush'));

But it logs null . Is there anyway I can test the template directives ?