SwiftUI Previews for UIKit

SampleTableViewCell.swift

import UIKit

final class SampleTableViewCell: UITableViewCell {
  
    static let cellHeight: CGFloat = 60.0
  
    static let reuseIdentifier: String = String(describing: SampleTableViewCell.self)
  
    private let nameLabel: UILabel = UILabel()
   
    func update(with model: String) {
       nameLabel.text = model
    }
}

#if DEBUG
#if targetEnvironment(simulator)
import SwiftUI

@available(iOS 13.0, *)
struct SampleTableViewCell_Previews: PreviewProvider {
    
    static var devices = ["iPhone 13 Pro Max"]
    
    static var platform: PreviewPlatform? {
        return SwiftUI.PreviewPlatform.iOS
    }
    
    static var previews: some SwiftUI.View {
        
        let height: CGFloat = SampleTableViewCell.cellHeight
        
        ForEach(devices, id: \.self) { deviceName in
            
            VStack(alignment: .center, spacing: 10) {
                
                UIViewPreview {
                        
                    let view = SampleTableViewCell(style: UITableViewCell.CellStyle.default, reuseIdentifier: SampleTableViewCell.reuseIdentifier)
                    view.update(with: "Test")
                    return view
                }
                .frame(minWidth: 70, maxWidth: .infinity, minHeight: height, maxHeight: height, alignment: .center)
                
                Spacer()
            }
            .previewDevice(PreviewDevice(rawValue: deviceName))
            .previewDisplayName(deviceName)
        }
        
    }
}
#endif
#endif

SampleView.swift

import UIKit
final class SampleView: UIView {
    
    private let nameLabel: UILabel = UILabel()
   
    func update(with model: String) {
       nameLabel.text = model
    }
}

#if DEBUG
#if targetEnvironment(simulator)
import SwiftUI

@available(iOS 13.0, *)
struct SampleView_Previews: PreviewProvider {
    
    static var devices = ["iPhone 13 Pro Max"]
    
    static var platform: PreviewPlatform? {
        return SwiftUI.PreviewPlatform.iOS
    }
    
    static var previews: some SwiftUI.View {
        
        ForEach(devices, id: \.self) { deviceName in
            VStack(alignment: .center, spacing: 10) {
                
                UIViewPreview {
                    
                    let view = SampleView(frame: CGRect.zero)
                    view.update(with: "Test")
                    return view
                }
                .frame(minWidth: 70, maxWidth: .infinity, minHeight: 0.0, maxHeight: .infinity, alignment: .center)
                
            }
            .previewDevice(PreviewDevice(rawValue: deviceName))
            .previewDisplayName(deviceName)
        }
        
    }
}
#endif
#endif

SampleViewController.swift

import UIKit
final class SampleViewController: UIViewController {

}

#if DEBUG
#if targetEnvironment(simulator)
import SwiftUI

@available(iOS 13.0, *)
struct SampleViewController_Previews: PreviewProvider {
    
    static var devices = ["iPhone 13 Pro Max"]
    
    static var platform: PreviewPlatform? {
        return SwiftUI.PreviewPlatform.iOS
    }
    
    static var previews: some SwiftUI.View {
        
        ForEach(devices, id: \.self) { deviceName in
            Group {
                
                UIViewControllerPreview {
                    
                    let vc = SampleViewController()
                    return vc
                }
                .frame(minWidth: 70, maxWidth: .infinity, minHeight: 0.0, maxHeight: .infinity, alignment: .center)
                
            }
            .previewDevice(PreviewDevice(rawValue: deviceName))
            .previewDisplayName(deviceName)
        }
        
    }
}
#endif
#endif

UIViewControllerPreview.swift

import SwiftUI
import UIKit

@available(iOS 13.0, *)
struct UIViewControllerPreview: SwiftUI.View {
    
    private let factory: () -> UIViewController
    
    init(factory: @escaping () -> UIViewController) {
        self.factory = factory
    }
    
    var body: some SwiftUI.View {
        Renderer(factory)
    }
    
    private struct Renderer: UIViewControllerRepresentable {
        
        private let factory: () -> UIViewController
        
        init(_ factory: @escaping () -> UIViewController) {
            self.factory = factory
        }
        
        func makeUIViewController(context: Context) -> UIViewController {
            return factory()
        }
        
        func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
            
        }
        
    }
   
}

UIViewPreview.swift

import SwiftUI
import UIKit

@available(iOS 13.0, *)
struct UIViewPreview: SwiftUI.View {
    
    private let factory: () -> UIView
    
    init(factory: @escaping () -> UIView) {
        self.factory = factory
    }
    
    var body: some SwiftUI.View {
        Renderer(factory)
    }
    
    private struct Renderer: UIViewRepresentable {
        
        private let factory: () -> UIView
        
        init(_ factory: @escaping () -> UIView) {
            self.factory = factory
        }
        
        func makeUIView(context: Context) -> UIView {
            return factory()
        }
        
        func updateUIView(_ uiView: UIView, context: Context) {
            
        }
        
    }
   
}