mocking_in_swift_mock.swift

public final class NetworkClient {
    private let n: NetworkClientProtocol

    init(n: NetworkClientProtocol = URLSession.shared) {
        self.n = n
    }

    func executeRequest(request: URLRequest, completion: @escaping (Result<Data, Error>) -> Void) {
        n.executeRequest(request: request){ (data, error) in
            if let error = error {
                completion(.failure(error))
                return
            }
            guard let data = data else {
                completion(.failure(NetworkError.noData))
                return
            }
            completion(.success(data))
        }
    }
}