15. Testing Angular apps

describe("OrderCard", () => {
  it("emits the id when clicked", async () => {
    await TestBed.configureTestingModule({ imports: [OrderCard] }).compileComponents();
    const fixture = TestBed.createComponent(OrderCard);
    fixture.componentRef.setInput("order", { id: 7, customer: "Asha", total: 500, status: "paid" });
    let emitted: number | undefined;
    fixture.componentInstance.select.subscribe(id => (emitted = id));
    fixture.detectChanges();
    fixture.nativeElement.querySelector("button").click();
    expect(emitted).toBe(7);
  });
});

// Services with HTTP
TestBed.configureTestingModule({ providers: [provideHttpClient(), provideHttpClientTesting()] });
const httpMock = TestBed.inject(HttpTestingController);
httpMock.expectOne("/api/orders").flush([]);