APIRequest-ProcessResponse.Swift

extension APIRequest {
    public static func processResponse<T: Codable, E: Codable>(
        _ dataOrNil: Data?,
        _ urlResponseOrNil: URLResponse?,
        _ errorOrNil: Error?,
        onSuccess: ((_: T) -> Void),
        onError: ((_: E?, _: Error) -> Void)) {

        if let data = dataOrNil {
            do {
                let decodedResponse = try JSONDecoder().decode(T.self, from: data)
                onSuccess(decodedResponse)
            } catch {
                let originalError = error

                do {
                    let errorResponse = try JSONDecoder().decode(E.self, from: data)
                    onError(errorResponse, APIError.errorResponseDetected)
                } catch {
                    onError(nil, originalError)
                }
            }
        } else {
            onError(nil, errorOrNil ?? APIError.noData)
        }
    }
}