BottomSheetWithDetentsSwiftUI.swift

import UIKit
import SwiftUI

// Hacky workaround, use at your own risk and all that
struct BottomSheetPresenter<Content>: UIViewRepresentable where Content: View{
    let label: String
    let content: Content
    let detents: [UISheetPresentationController.Detent]
    
    init(_ label: String, detents: [UISheetPresentationController.Detent], @ViewBuilder content: () -> Content) {
        self.label = label
        self.content = content()
        self.detents = detents
    }
    
    func makeUIView(context: UIViewRepresentableContext<BottomSheetPresenter>) -> UIButton {
        let button = UIButton(type: .system)
        button.setTitle(label, for: .normal)
        button.addAction(UIAction { _ in
            let hostingController = UIHostingController(rootView: content)
            let viewController = UIBottomSheetWrapper(detents: detents)

            viewController.addChild(hostingController)
            viewController.view.addSubview(hostingController.view)
            hostingController.view.pinToEdgesOf(viewController.view)
            hostingController.didMove(toParent: viewController)
            
            button.window?.rootViewController?.present(viewController, animated: true)
        }, for: .touchUpInside)
        
        print("make...")
        
        return button
    }
    
    func updateUIView(_ uiView: UIButton, context: Context) {
        // no updates
    }
    
    func makeCoordinator() -> Void {
        return ()
    }
}

extension BottomSheetPresenter {
    class UIBottomSheetWrapper: UIViewController {
        let detents: [UISheetPresentationController.Detent]
        
        init(detents: [UISheetPresentationController.Detent]) {
            self.detents = detents
            super.init(nibName: nil, bundle: nil)
        }
        
        required init?(coder: NSCoder) {
            fatalError("No Storyboards")
        }
        
        override func viewDidLoad() {
            super.viewDidLoad()
            
            view.backgroundColor = .gray
            
            if let sheetController = self.presentationController as? UISheetPresentationController {
                sheetController.detents = detents
            }
        }
    }
}

extension UIView {
    func pinToEdgesOf(_ other: UIView) {
        translatesAutoresizingMaskIntoConstraints = false
        
        leftAnchor.constraint(equalTo: other.leftAnchor).isActive = true
        topAnchor.constraint(equalTo: other.topAnchor).isActive = true
        rightAnchor.constraint(equalTo: other.rightAnchor).isActive = true
        bottomAnchor.constraint(equalTo: other.bottomAnchor).isActive = true
    }
}

// Usage
struct ContentView: View {
    var body: some View {
        VStack {
            BottomSheetPresenter("Tap me for a bottom sheet!!", detents: [.medium(), .large()]) {
                VStack {
                    Text("This is a test")

                    Rectangle()
                        .frame(width: 300, height: 300, alignment: .leading)
                        .foregroundColor(.blue)
                }
            }
        }
    }
}

Thanks! 😁 I'll modify the gist to use your suggestion