Adding support for common error status codes like 404, 403 to the responseJson serializer in Alamofire.

AF Adding support for Common http errors:

// Adding support for common error status codes like 404, 403 to the responseJson serializer in Alamofire.

//
//  AlamofireAuto.swift
//  Speedy
//
//  Created by Grant Kemp on 12/02/2017.
//  Copyright © 2017 Grant Kemp. All rights reserved.
//

import Foundation
import Alamofire



extension Alamofire.Request {
	
	enum BackendError: Error {
		case network(error: Error) // Capture any underlying Error from the URLSession API
		case dataSerialization(error: Error)
		case jsonSerialization(error: Error)
		case xmlSerialization(error: Error)
		case objectSerialization(reason: String)
	}
	public static func serializeResponseJSONSimple(
		options: JSONSerialization.ReadingOptions,
		response: HTTPURLResponse?,
		data: Data?,
		error: Error?)
		-> Result<Any>
	{
		guard error == nil else {
			//error!.localizedDescription is the only property
			
			return .failure(error!) }
		
		if let response = response{ return .success(NSNull()) }
		
		guard let validData = data, validData.count > 0 else {
			return .failure(AFError.responseSerializationFailed(reason: .inputDataNilOrZeroLength))
		}
		
		do {
			let json = try JSONSerialization.jsonObject(with: validData, options: options)
			return .success(json)
		} catch {
			return .failure(AFError.responseSerializationFailed(reason: .jsonSerializationFailed(error: error)))
		}
	}

}

extension DataRequest {
	public static func jsonResponseSerializer(
		options: JSONSerialization.ReadingOptions = .allowFragments)
		-> DataResponseSerializer<Any>
	{
		return DataResponseSerializer { _, response, data, error in
			return Request.serializeResponseJSON(options: options, response: response, data: data, error: error)
		}
	}
	
	@discardableResult
	public func responseSimpleJSON(
		queue: DispatchQueue? = nil,
		options: JSONSerialization.ReadingOptions = .allowFragments,
		completionHandler: @escaping (DataResponse<Any>) -> Void)
		-> Self
	{
		return response(
			queue: queue,
			responseSerializer: DataRequest.jsonResponseSerializer(options: options),
			completionHandler: completionHandler
		)
	}
}