Angular: Unclear Why Intellij Produces Unresolved Variable Warning

Issue

I'm having a problem understanding why Intellij is producing an unresolved variable warning. I was hoping someone could explain why it happens.

I have an interface:

export interface Foo {
    property: string;
}

And an observable of that type in my component:

foo$: Observable<Foo>
    
ngOnInit() {
    this.foo$ = this._fooSvc.foo$;
}

The observable is retrieved from a service. The service declares the return type:

private _fooSubject: ReplaySubject<Foo>;

get foo$(): Observable<Foo> => {
    return _fooSubject.asObservable();
}

And I unwrap the observable in the template using the async pipe, where I get the warning:

[ngClass]="{my-class: (foo$ | async)?.fileName === null}"

So, I define a type and get an observable of that type in the component. I assign the component variable using a service method that declares a proper return type. Still get the warning.

What am I missing? Why do I get the "Unresolved variable fileName" warning in the template?

Solution

The issue is tracked at WEB-45419, please follow it for updates

Answered By - lena