Cannot invoke 'decode' with an argument list of type '(GenericDM.Type, from: String?)'

I've been using app.quicktype.io to generate the code to decode JSON. I'm facing a problem now that I have not seen before.

First, I have this simple struct:

import Foundation
struct GenericDM: Codable {

let status, statusMessage: String

let result: [Result]
enum CodingKeys: String, CodingKey {
    case status
    case statusMessage = "status_message"
    case result
}

}
struct Result: Codable {

let applicationID, applicationName, applicationType, suFirstName: String

let suMiddleName, suLastName, suAge, suDob: String

let suRace: String

let suAddress: SuAddress

let createdTime, updatedTime: Int
enum CodingKeys: String, CodingKey {
    case applicationID = "application_id"
    case applicationName = "application_name"
    case applicationType = "application_type"
    case suFirstName = "su_first_name"
    case suMiddleName = "su_middle_name"
    case suLastName = "su_last_name"
    case suAge = "su_age"
    case suDob = "su_dob"
    case suRace = "su_race"
    case suAddress = "su_address"
    case createdTime = "created_time"
    case updatedTime = "updated_time"
}

}
struct SuAddress: Codable {

let addrLine1, addrLine2, stName, addrCity: String

let addrState, addrCounty, addrPin: String
enum CodingKeys: String, CodingKey {
    case addrLine1 = "addr_line_1"
    case addrLine2 = "addr_line_2"
    case stName = "st_name"
    case addrCity = "addr_city"
    case addrState = "addr_state"
    case addrCounty = "addr_county"
    case addrPin = "addr_pin"
}

}
func newJSONDecoder() -> JSONDecoder {

let decoder = JSONDecoder()

if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {

decoder.dateDecodingStrategy = .iso8601

}

return decoder

}
func newJSONEncoder() -> JSONEncoder {

let encoder = JSONEncoder()

if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {

encoder.dateEncodingStrategy = .iso8601

}

return encoder

}
// MARK: - URLSession response handlers
extension URLSession {

fileprivate func codableTask<T: Codable>(with url: URL, completionHandler: @escaping (T?, URLResponse?, Error?) -> Void) -> URLSessionDataTask {

return self.dataTask(with: url) { data, response, error in

guard let data = data, error == nil else {

completionHandler(nil, response, error)

return

}

completionHandler(try? newJSONDecoder().decode(T.self, from: data), response, nil)

}

}
func genericDMTask(with url: URL, completionHandler: @escaping (GenericDM?, URLResponse?, Error?) -&gt; Void) -&gt; URLSessionDataTask {
    return self.codableTask(with: url, completionHandler: completionHandler)
}

}

Then, I read a JSON file and try to decode the data from a different class:

    let bundle = Bundle.main

let path = bundle.path(forResource: “MockGenericData”, ofType: “json”)

let jsonData = try? String.init(contentsOf: URL.init(fileURLWithPath: path!))

let genericDM = try? newGenericDMJSONDecoder().decode(GenericDM.self, from: jsonData)

I temporarily need to read from that mockup file before I can get it from the backend.

However, I’m getting Cannot invoke ‘decode’ with an argument list of type ‘(GenericDM.Type, from: String?)’ and I don’t understand why.

Anybody has any idea?

#json #swift