Success

About

This simple package presents a way to easily handle a success or failed result, which could be, for example, the result of an API request.

How to

This package contains only 3 classes, Result and its subtypes - Success and Failure. You can use these classes in your code to handle errors without having to do a try catch whenever possible.

Usage

enum RequestErrorCode {
  noInternet,
  sessionExpired,
  unexpectedError,
}

Result<Response, RequestErrorCode> getUsername() {
  try {
    final response = api.getUsername();
  } on ApiError catch (err) {
    if (err.connectionInterrupted) {
      return Result.failure(RequestErrorCode.noInternet);
    } else if (err.statusCode == 401) {
      return Result.failure(RequestErrorCode.sessionExpired);
    } else {
      return Result.failure(RequestErrorCode.unexpectedError);
    }
  } on Exception {
    return Result.failure(RequestErrorCode.unexpectedError);
  }
}

void main() {
  final result = getUsername();

  switch (result) {
    case Success(value: final username):
      print('My username is: "$username".');
      break;
    case Failure(value: RequestErrorCode.noInternet):
      print('Internet connection is not available.');
      break;
    case Failure(value: RequestErrorCode.sessionExpired):
      print('Session has expired.');
      break;
    case Failure():
      print('Unexpected error while getting the username.');
      break;
  }
}