weather_state.dart redundant properties for FailState and NotFoundState

[philite]

@JsonSerializable()
class FailState extends WeatherState {
  const FailState({required String cityName, required Units units})
      : super(cityName: cityName, units: units);

  factory FailState.fromJson(Map<String, dynamic> json) =>
      _$FailStateFromJson(json);

  Map<String, dynamic> toJson() => _$FailStateToJson(this);
}

@JsonSerializable()
class NotFoundState extends WeatherState {
  const NotFoundState({required String cityName, required Units units})
      : super(cityName: cityName, units: units);

  factory NotFoundState.fromJson(Map<String, dynamic> json) =>
      _$NotFoundStateFromJson(json);

  Map<String, dynamic> toJson() => _$NotFoundStateToJson(this);
}

I don't see cityName and units use anywhere for FailState and NotFoundState

[philite]

I suggest you read and use this instead Creating a Non-Instantiable, Non-Extendable Class and Are there any sealed classes alternatives in Dart 2.0?

[philite]

a better implementation for Kotlin's sealed class in Dart dart-lang/language#349 (comment)