Always throws UnimplementedError about blocfromzerotohero

[absarrahman]

I faced the same issue. Just remove throw UnimplementedError();

[flutternoob]

Try the following code in the main-bloc.dart file:

@override
  Stream<int> mapEventToState(CounterEvent event) async* {
    try {
      switch (event) {
        case CounterEvent.increment:
          yield state + 1;
          break;
        case CounterEvent.decrement:
          yield state - 1;
          break;
      }
    } catch (error) {
      throw UnimplementedError();
    }
  }

You can check if the UnimplementedError() will be thrown by attempting a divide by zero calculation for one of the cases. The error will be thrown, thereby showing that the try...catch block works.