FetchAlamofire.swift

func fetch<Model: Codable> (fromRoute route: Route<Model>, then: @escaping (Result<Model>) -> Void) {

    // make sure that the endpoint path is a valid URL
    guard let url = URL(string: self.baseURL+route.endpoint) else {
        then(.failure(NSError(domain: "warpfactor.io", code: 500)))
        return
    }

    Alamofire
        .request(url, method: route.httpMethod)
        .responseData { (response) in
            guard response.error == nil else {
                then(.failure(response.error!))
                return
            }

            if  let data = response.data,
                let model = try? JSONDecoder().decode(Model.self, from: data) {
                then(.success(model))
            } else {
                then(.failure(NSError(domain: "warpfactor.io", code: 1000, userInfo: ["error":"wrong model"])))
            }
    }
}