Testing an HttpInterceptor

My unit test for my HttpInterceptor is unfortunately not working and I have no idea how to solve this right now

Example => error.interceptor.ts

@Injectable()
export class ErrorInterceptor implements HttpInterceptor {

    public intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        return next.handle(request).pipe(
            catchError((response) => this.handleError(response)),
        );
    }

    private handleError(response: HttpErrorResponse): Observable<HttpEvent<any>> {
        if (response.status === 500 || response.status === 501) {
            console.log('Error');
        }
        return throwError(() => response);
    }
}

Unit-Test => error.interceptor.spec.ts

let errorInterceptor: ErrorInterceptor;

beforeEach(() => {
    errorInterceptor = new ErrorInterceptor(
    );
});


it.each([500, 501])('should  ...', (statusCode) => {
    const response = new HttpErrorResponse({ status: (statusCode) });
    const request = new HttpRequest('GET', '/fakeUrl');
    const mockHandler = { handle: jest.fn(() => throwError(() => response )) };
    const result = errorInterceptor.intercept(request, mockHandler);

    result.subscribe({
        next: () => fail('error'),
        error: (err) => expect(err).toBeTruthy(),
    });
});

This test works. But if I change toBeTruthy to toBeFalsy the test works also :-(

Either the error is in result.subscribe or my beforeEach() is not correct.