Function selectFirstOption

src/material/select/select.spec.ts:2018–2027

()

        let spy = jasmine.createSpy('option selection spy');
        let subscription = fixture.componentInstance.select.optionSelectionChanges.subscribe(spy);
        let selectFirstOption = async () => {
          trigger.click();
          fixture.detectChanges();
          await fixture.whenRenderingDone();

          const option = getOverlayHost(fixture)?.querySelector('mat-option') as HTMLElement;
          option.click();
          fixture.detectChanges();
          await fixture.whenRenderingDone();
        };

        fixture.componentInstance.foods = [{value: 'salad-8', viewValue: 'Salad'}];
        fixture.changeDetectorRef.markForCheck();