Global error mapping

[Kevin Renskers]

It would be nice to set a global error mapping. My API returns errors in a certain format, so I now have to add .mapError every time I make a request.

PasswordResetTokenRequest(email: email)
  .schedule(with: api)
  .receive(on: DispatchQueue.main)
  .mapError(CoreAPIError.fromError)
  .sink(
    // etc

CoreAPIError looks like this, in case you're wondering:

struct CoreAPIError: Decodable, Error, LocalizedError {
  let message: String?
  let errors: [String: [String]]?

  var errorDescription: String? {
    if let errors = errors {
      let values = errors.flatMap { $0.value }
      return values.joined(separator: "\n")
    }
    return message ?? "An error occured"
  }

  static func fromError(_ error: Squid.Error) -> CoreAPIError {
    if case .requestFailed(_, let data) = error, let coreError = try? JSONDecoder().decode(CoreAPIError.self, from: data) {
      return coreError
    }

    return CoreAPIError(message: error.localizedDescription, errors: nil)
  }
}

The problem is that I always have to remember to add this one line to every call site. It would be great if it would be possible to set this as a default, global thing that happens to all requests.

[Kevin Renskers]

This is not too bad. Still have to remember to do it at the call site, but at least it's right there in the autocompletion popup when I type .schedule :)

extension Request {
  func scheduleAndMapError(with service: HttpService) -> AnyPublisher<Self.Result, CoreAPIError> {
    return schedule(with: service)
      .mapError(CoreAPIError.fromError)
      .eraseToAnyPublisher()
  }
}

[Oliver Borchert]

I will include that feature into the HttpService protocol, definitely makes sense ;)

[Oliver Borchert]

https://github.com/borchero/Squid/releases/tag/1.4.0

[Kevin Renskers]

Thanks!