RxJS operator to handle errors

myhandle.component.ts

// https://stackoverflow.com/questions/52797992/which-rxjs-operator-to-choose-to-handle-http-errors-tap-or-catcherror/61836193#61836193
// "tap" is to cause side effects and it doesn't modify the chain at all, "catchError" is to catch errors in a stream and try to handle them.
http.get('https://test.com/').pipe(
    tap(
        () => {
            // 200, awesome!, no errors will trigger it.
        },
        (error: HttpErrorResponse) => {
            // error is here, but we can only call side things.
        },
    ),
    catchError(
        (error: HttpErrorResponse): Observable<any> => {
            // we expect 404, it's not a failure for us.
            if (error.status === 404) {
                return of(null); // or any other stream like of('') etc.
            }

            // other errors we don't know how to handle and throw them further.
            return throwError(error);
        },
    ),
).subscribe(
    response => {
        // 200 triggers it with proper response.
        // 404 triggers it with null. `tap` can't make 404 valid again.
    },
    (error: HttpErrorResponse) => {
        // any error except 404 will be here.
    },
);