How do I use catchError() and still return a typed Observable with rxJs 6.0?

Question

cdSo I\'m trying to migrate some of my Angular 5 code to 6, and I understand most of the changes required for rxjs to work using the .pipe() operator. It works as you would expe

Answer 1

You should be able to explicitly specify the type parameters to catchError to indicate that it won't return an observable that emits a value - that is, it will return Observable<never> - and will always throw:

getAlbums(): Observable<Album[]> {
    return this.httpClient.get<Album[]>(this.config.urls.url("albums"))
        .pipe(
            map(albumList => this.albumList = albumList),
            catchError<Album[], never>(new ErrorInfo().parseObservableResponseError)
        );           
}

Doing so will see the type inferred from the pipe call to be Observable<Album[]>.