Properly Testing an Observable for Simple Component

I am currently testing a simple component that I have created that looks like this:

@Input()
public type: string;

private saveSubscription: Subscription;

public ngOnDestroy(): void {
    this.saveSubscription.unsubscribe();
}

public ngOnInit(): void {
    this.onSave();
}

private onSave(): void {
    this.saveSubscription = this.editService.saveSelection.subscribe(() => {
        this.editService.type.next(this.type);
    });
}

In my test, I want to make sure that if I set the input manually, and then call ngOnInit(), the value emitted by the editService will equal my value.

it('should set up the subscription for saving', fakeAsync(() => {
    // Arrange
    component.type = 'full';

    // Act
    component.ngOnInit();
    fixture.detectChanges();

    mockedEditService.saveSelection.next();

    // Assert
    mockedEditService.type.subscribe(type => {
        expect(type).toEqual(component.type);
    });
}));

I'm struggling with testing async code and am not sure if I am doing this correctly. The test always passes even with incorrect test cases and I suspect that the code in question is not waiting for the subscription to resolve before making its assertion.

Reading the Angular test docs, I've been able to familiarize myself a bit more, but I was wondering if you all had any suggestions.

Thanks