Demo showing how dio can freeze/crash the app if an error occurs inside the interceptor

dio_freeze_interceptor.dart

import 'package:dio/dio.dart';

Future<void> main() async {
  final dio = Dio();

  //Using the same dio instance: crash
  dio.interceptors.add(InterceptorWithError(dio));

  //Using different instance: works
  //dio.interceptors.add(InterceptorWithError(Dio()));

  try {
    final response = await Future.wait([
      dio.get('https://1'),
      dio.get('https://2'),
    ]);
    print('Response: ${response.length}');
  } catch (e) {
    print('Unreachable code: $e');
  }

  print('Code end');
}

class InterceptorWithError extends QueuedInterceptorsWrapper {
  final Dio dio;

  InterceptorWithError(this.dio);

  @override
  Future<void> onRequest(
    RequestOptions options,
    RequestInterceptorHandler handler,
  ) async {
    print('Request: ${options.path}');
    return handler.next(options);
  }

  @override
  Future<void> onError(
    DioException err,
    ErrorInterceptorHandler handler,
  ) async {
    var requestOptions = err.requestOptions;

    try {
      handler.resolve(await dio.fetch(requestOptions.copyWith(
        path: (err.requestOptions.path.contains('1'))
            ? 'https://www.xoogle.com'
            : 'https://www.google.com',
      )));
    } catch (e) {
      print('Quebrou o fetch ---> $e');
      handler.next(err);
    }
  }
}