Asynchronous Calls with FutureKit

VillainService.swift

import FutureKit
import SwiftyJSON

class VillainService {
    let url: String
    var session: URLSession = URLSession.shared

    func getVillainList() -> Future<VillainResponse> {
        let promise = Promise<VillainResponse>()
        
        var request = URLRequest(url: URL(string: "http://www.wearevillains.com/team"))
        request.httpMethod = "GET"
            
        let task = session.dataTask(with: request) { data, response, error in
            if error != nil {
                promise.completeWithFail(error!)
            } else {
                do {
                   if let convertedJsonIntoDict = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary {
                            let dataAsJson = JSON(convertedJsonIntoDict)
                            promise.completeWithSuccess(APIRootResourceLinks.init(fromJSON: dataAsJson)!)
                    }
                } catch let error as NSError {
                        promise.completeWithFail(error)
                }
            }
            
        task.resume()
        
        return promise.future
    }
}

extension Villain : JSONDeserializable {
    init?(fromJSON json: JSON) {
        guard let name = json["name"].string else { return nil }
        guard let specialty = json["specialty"].string else { return nil }
    }
}

extension VillainResponse : JSONDeserializable {
    init?(fromJSON json: JSON) {
        guard let
            villainCount = json["villainCount"].int,
            let villains = json["villains"].array {
               for (index, vill) in villains.enumerated() {
                   if let villain = Villain(fromJson: json["villains"][index]) {
                      villains.append(villain)
                   }
                }
        } else { return nil }

        count = villainCount
        villains = villains
    }
}