javascript - 如何修复(错误:any)=>Observable<any> is not assignable?

Question

在saveExpense()方法中，当传递错误处理catchError (this.handleError<any>('Add Expense', []))时，此方法将突出显示并显示错误: Argument type (error:any)=>Observable<any> is not assignable to parameter type (err:any, caught:Observable<T>)=>never。怎么解决？

    saveExpense(userid, oExpense) {
        const httpOptions = {
            headers: new HttpHeaders({
                'Content-Type': 'application/json',
                'Authorization': `${this.jwtToken}`
            })
        };
    return this.http.post(`http://localhost:5555/api/expense/${userid}`, JSON.stringify(oExpense), httpOptions).pipe(
        tap(
            (response: ServerMessage) => console.log(response)
        ),
        catchError(this.handleError('Add Expense', []))
    );
}

    private handleError<T>(operation = 'operation', result?: T) {
        return (error: any): Observable<T> => {
            console.error(error);
            console.log(`${operation} failed: ${error.message}`);
            return of(result as T);
        };
    }

Answer 1

该语句表示希望给catchError()一个以(err:any, caught:Observable<T>)=>never签名为参数的函数。

传递给catchError()的函数的签名(参数和返回类型)是什么？