UIKit ViewController SwiftUI Preview sample

UIViewControllerPreview.swift

#if canImport(SwiftUI) && DEBUG
import SwiftUI

@MainActor
fileprivate struct UIViewControllerPreview<T: UIViewController>: UIViewControllerRepresentable {
    let viewController: T
    init(_ builder: @escaping () -> T) { viewController = builder() }
    func makeUIViewController(context: Context) -> T { viewController }
    func updateUIViewController(_ uiViewController: T, context: Context) { }
}

@MainActor
fileprivate struct LoginViewController_Previews: PreviewProvider {
    static var previews: some View {
        UIViewControllerPreview {
            UIStoryboard(name: "Login", bundle: nil).instantiateViewController(withIdentifier: "login") as UIViewController
        }
    }
}
#endif