Generic structures to host previews of UIView and UIViewController subclasses. Also NSView and NSViewController

NSView_Preview_CodeSnippet.swift

#if canImport(SwiftUI) && DEBUG
import SwiftUI

struct <#NSView#>_Preview: PreviewProvider {
    
    static var previews: some View {
        NSViewPreview {
            <#Code#>
        }
    }
    
}

#endif

NSViewController_Preview_CodeSnippet.swift

#if canImport(SwiftUI) && DEBUG
import SwiftUI

struct <#NSViewController#>_Preview: PreviewProvider {
    
    static var previews: some View {
        NSViewControllerPreview {
            <#Code#>
        }
    }
    
}

#endif

NSViewControllerPreview.swift

import Cocoa

#if canImport(SwiftUI) && DEBUG
import SwiftUI
struct NSViewControllerPreview<ViewController: NSViewController>: NSViewControllerRepresentable {
    
    let viewController: ViewController
    
    init(_ builder: @escaping () -> ViewController) {
        viewController = builder()
    }
    
    // MARK: - NSViewControllerRepresentable
    
    func makeNSViewController(context: Context) -> ViewController {
        return viewController
    }
    
    func updateNSViewController(_ viewController: ViewController, context: Context) {
        
    }
    
}
#endif

NSViewPreview.swift

import Cocoa

#if canImport(SwiftUI) && DEBUG
import SwiftUI
struct NSViewPreview<View: NSView>: NSViewRepresentable {
    
    let view: View
    
    init(_ builder: @escaping () -> View) {
        view = builder()
    }
    
    // MARK: - NSViewRepresentable
    func makeNSView(context: Context) -> View {
        return view
    }
    
    func updateNSView(_ view: View, context: Context) {
        view.setContentHuggingPriority(.defaultHigh, for: .horizontal)
        view.setContentHuggingPriority(.defaultHigh, for: .vertical)
    }
    
}
#endif

UIView_Preview_CodeSnippet.swift

#if DEBUG
import SwiftUI
struct <#UIView#>_Preview: PreviewProvider {
    static var previews: some View {
        UIViewPreview {
            <#Code#>
        }
    }
}
#endif

UIViewController_Preview_CodeSnippet.swift

#if DEBUG
import SwiftUI
struct <#UIViewController#>_Preview: PreviewProvider {
    static var previews: some View {
        UIViewControllerPreview {
            <#Code#>
        }
    }
}
#endif

UIViewControllerPreview.swift

import UIKit

#if canImport(SwiftUI) && DEBUG
import SwiftUI
struct UIViewControllerPreview<ViewController: UIViewController>: UIViewControllerRepresentable {
    let viewController: ViewController

    init(_ builder: @escaping () -> ViewController) {
        viewController = builder()
    }

    // MARK: - UIViewControllerRepresentable

    func makeUIViewController(context: Context) -> ViewController {
        return viewController
    }

    func updateUIViewController(_ viewController: ViewController, context: Context) {
        return
    }
}
#endif

UIViewPreview.swift

import UIKit

#if canImport(SwiftUI) && DEBUG
import SwiftUI
struct UIViewPreview<View: UIView>: UIViewRepresentable {
    let view: View

    init(_ builder: @escaping () -> View) {
        view = builder()
    }

    // MARK: - UIViewRepresentable

    func makeUIView(context: Context) -> UIView {
        return view
    }

    func updateUIView(_ view: UIView, context: Context) {
        view.setContentHuggingPriority(.defaultHigh, for: .horizontal)
        view.setContentHuggingPriority(.defaultHigh, for: .vertical)
    }
}
#endif