playgroundRender.swift

import PlaygroundSupport
import SwiftUI
extension UIView {
    var renderedImage: UIImage {
        let image = UIGraphicsImageRenderer(size: self.bounds.size).image { context in
            UIColor.lightGray.set(); UIRectFill(bounds)
            context.cgContext.setAlpha(0.75)
            self.layer.render(in: context.cgContext)
        }
        return image
    }
}
extension View {
    var renderedImage: UIImage {
        let window = UIWindow(frame: CGRect(origin: .zero, size: CGSize(width: 320, height: 160)))
        let hosting = UIHostingController(rootView: self)
        hosting.view.frame = window.frame
        window.rootViewController = hosting
        window.makeKey()
        return hosting.view.renderedImage
    }
}

Text("Hello").renderedImage

Slider(value: .constant(0.5)).renderedImage
let view = ([Color.red, .orange, .yellow, .green, .blue, .purple]
    .reduce(AnyView(Text("👭").font(.largeTitle)
        .rotationEffect(Angle(radians: .pi)))) {
            AnyView($0.padding()
                .background($1)
                .rotationEffect(Angle(radians: .pi / 6)))
})

PlaygroundPage.current.liveView = UIHostingController(rootView: view)