Simple extension for Previews of UIView and UIViewController.

UIViewControllerSwiftUIRepresentable.swift

#if DEBUG
#if canImport(SwiftUI)
import UIKit
import SwiftUI

@available (iOS 13.0, *)
struct UIViewControllerSwiftUIRepresentable: UIViewControllerRepresentable {
    let controller: UIViewController
    
    func makeUIViewController(context: Context) -> UIViewController {
        return controller
    }
    
    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}
}

@available (iOS 13.0, *)
extension UIViewController {
    var sRepresentation: some View {
        return UIViewControllerSwiftUIRepresentable(controller: self)
    }
}
#endif
#endif

UIViewSwiftUIRepresentable.swift

#if DEBUG
#if canImport(SwiftUI)
import UIKit
import SwiftUI

@available (iOS 13.0, *)
struct UIViewSwiftUIRepresentable: UIViewRepresentable {
    let view: UIView
    
    func makeUIView(context: Context) -> UIView {
        return view
    }
    
    func updateUIView(_ uiView: UIView, context: Context) {}
}

@available (iOS 13.0, *)
extension UIView {
    var sRepresentation: some View {
        return UIViewSwiftUIRepresentable(view: self)
    }
}
#endif
#endif