test.swift

import SwiftUI

struct Item: Identifiable {
    var id: String { "abc" }
    var title: String = "abcfoo"
}

extension View {
    func popup<Item, Content>(item: Binding<Item?>, @ViewBuilder content: (Item) -> Content) -> some View where Item: Identifiable, Content: View {
        return ZStack(alignment: .top, content: {
            self
            item.wrappedValue.map { unwrapped in
                Group {
                    Color.black.opacity(0.8)
                        .transition(AnyTransition.opacity.animation(.easeInOut(duration: 0.15)))
//                        .tappable {
//                            item.wrappedValue = nil
//                        }
                    content(unwrapped)
                        .animation(.easeInOut(duration: 0.3))
                        .transition(.move(edge: .top))
                }
            }
        })
    }
}

struct SheetView: View {
    @Environment(\.presentationMode) var presentationMode

    var body: some View {
        Button("Press to dismiss") {
            presentationMode.wrappedValue.dismiss()
        }
        .font(.title)
        .padding()
        .background(Color.black)
    }
}

struct ContentView: View {
    @State private var showingSheet = false
    @State var item: Item? = Item()

    var body: some View {
        Button("Show Sheet") {
            showingSheet.toggle()
        }
        .sheet(isPresented: $showingSheet) {
            VStack {
                Text("Hello")
            }
            .popup(item: self.$item, content: { test in
                VStack {
                    Text(test.title)
                }
            })
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}