How do you test asynchronous code in Angular tests?

• Use async/await with Angular's waitForAsync or Jasmine’s done callback.
• Use Angular’s fakeAsync and tick() to simulate asynchronous passage of time.

Example with fakeAsync:

it('should fetch data asynchronously', fakeAsync(() => {

let data;

service.getData().subscribe(result => data = result);

tick(); // simulate async time passing

expect(data).toEqual(['expected data']);

}));