Dio: Unable to catch DioError

[psgainz]

New Issue Checklist

• [ Yes ] I have searched for a similar issue in the project and found none

Issue Info

| Info | Value | |
| ------------------------------ | ----------------------------------------------------- | ---- |
| Platform Name | Flutter - Android | |
| Platform Version | 6.0 | |
| Dio Version | e.g. 3.0.7 | |
| Visual Studio Code | VSCode 1.36.0 | |
| Repro rate | 100% | |
| Repro with our demo prj | NA | |
| Demo project link | NA | |

Issue Description and Steps

Code Snippet

try {
      response = await dio.post(
        'https://wendux.github.io/xsddddd',
        data: data,
        onSendProgress: (sent, total) {
          if (total != -1) {
            pr.update(
              progress: (sent / total * 100),
              message: 'Sending File : ' + ((sent / total * 100).toInt()).toStringAsFixed(0) + "%",
            );
            if(sent == total) print('Sent');
          }
        },
        //Handle Exceptions here (Issues in receiving data - memory or else)
        onReceiveProgress: (received, total) {
          if(total != -1) {
            pr.update(
              progress: (received / total * 100),
              message: 'Receiving Data : ' + ((received / total * 100).toInt()).toStringAsFixed(0) + "%",
            );
            if(received == total) print('Received');
          }
        }
      );
    }
    on DioError catch(e) {
      print(e.response.data);
      print(e.response.headers);
      print(e.response.request);
      await showAlertDialog(context,
       alertTitle: 'Internet Connection Error',
        alertText: 'Please check you internet connection & try again',
        numberButtons: 1
      );
      cancelOp = true;

    }

In dispatchRequest, exception being thrown here
DioError err = assureDioError(e, options); throw err;

However it is not caught by the above code snippet

[ffpetrovic]

Same here, can't catch with catch(e) in general, not just on DioError.

[psgainz]

It looks like the issue is due to Flutter framework. Many exceptions of several packages are not caught when running the app in DEBUG Mode. However, I noticed that when you run your application in RELEASE Mode, everything seems to work fine (though mostly, & I don't think every time). Waiting for the dio team to share their opinion on it @ffpetrovic

[ffpetrovic]

Does latest flutter have this issue? @psgainz

[psgainz]

Unfortunately yes!
The only option is to test in RELEASE Mode whenever you feel to test the exception.

[ffpetrovic]

Thanks @psgainz
Did you find this somewhere? Is there an issue for this on the flutter repo?

[psgainz]

I accidentally encountered it while testing in RELEASE Mode. Also, in some stackoverflow post, I read that this issue also persists for google_sign_in package. Exceptions are not caught when thrown by the package. Only in RELEASE Mode, some exceptions are caught, while some exceptions simply do not occur.

https://stackoverflow.com/questions/51914691/flutter-platform-exception-upon-cancelling-google-sign-in-flow

[ffpetrovic]

Yes, I have had this problem with google sign in and also read that release mode fixes it.

[urusai88]

Hello everybody! I have a same problem without any "google signin flow", i am just trying to make http request.
Standart dart HttpClient works well.

[psgainz]

Closing the issue as the exception works correctly in RELEASE Mode

[ffpetrovic]

Debugging in RELEASE mode is very limited. This is not a valid excuse.

[talski]

a workaround is disable all breakpoints in run tab sidebar, the error will be catched and the app will flow

[VenatusSimpleX]

@talski's workaround is not optimal, as we want to catch all uncaught error if possible to prevent accidental crashes. Any plans at all to fix this?

[RaoSaqib7860]

i am handle in this way on debug mode I know its not good practice
Options(
headers: {'Authorization': 'Bearer $token'},
followRedirects: false,
validateStatus: (status) {
return status <= 500;
}
)