how_unit_testing_can_help_write_better_designs_6.swift

extension ClientProtocol {

    func get<Model>(path: String, completion: @escaping (Result<Model, ClientError>) -> Void) where Model: Decodable {
        get(path: path) { (result: Result<Data, ClientError>) in
            switch result {
            case .success(let data):
                do {
                    let model = try JSONDecoder().decode(Model.self, from: data)
                    completion(.success(model))
                } catch {
                    completion(.failure(.parsing(error)))
                }

            case .failure(let error):
                completion(.failure(error))
            }
        }
    }
}