Will my Angular App "break" if the Error is not declared on Observable.Subscribe?-CodePudding

I'm doing some refactor on my Angular App, and implementing interceptors like a common ErrorHttpInterceptor.

On my tests I noticed My question is, if I remove the "error" paramater from Subscribe on my observables request it trigger an error. If I let it there, the subscribe error trigger, but apparently my app don't break.

I say apparently cause I'm not being able to properly test if the app breaks or not.

This is my "test" method:

testAPI(){
    this.myservice.getRequest().subscribe({
        next: data => console.log(data),
        error: error => console.log(error)
    });
}

This is my simplified ErrorInterceptor:

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

    return next.handle(request).pipe(
        catchError(error => throwError(() => error))
    );

}

I want to know if its ok or reliable to leave my Subscribe like this:

testAPI(){
        this.myservice.getRequest().subscribe({
            next: data => console.log(data)
        });
    }

And trust solenly on ErrorInterceptor to catch and process errors

CodePudding user response：

If you want your Interceptor to do all your Http Error handling then using Promises and not using subscribe is a cleaner way

Here is a cleaner way of doing it:

Implement your Interceptor like you did but return an EMPTY in your catchError method instead of doing a throw and do a console.error() of the error (you can add the error in a toast as well), because you do not want your app to break everytime an error occurs, you want it to continue.

In your service making the API request:

async saveAddressDetails(user: User): Promise<any> {
        return await this.http.post<any>(`${this.authURL}update/address`, user).toPromise();
    }

In component where you use the HTTP request:

    const result = await this.auth.saveAddressDetails(this.auth.user);
    
    if (result) {
        this.toast.success('Address Details saved');
    }

Notice that if you have an error result will be null and thus the code in the if will not be computed.