How to handle SwiftUI sheet(item:onDismiss:content) unwrapping of optional whilst allowing binding to be passed to sheet view

TestView.swift

//
// This demonstrates how to use sheet(item:...) when the requirement is to pass a binding to the 
// view presented by the sheet.  Also relevant to fullCoverSheet(item:...)
//
// What we want the sheet to do is provide an editable form that can be cancelled, so partial changes 
// are not committed to the ancestors view state.  We only want the state changed IF the form is confirmed (save action)
//

import SwiftUI

struct Movie: Identifiable {
    var id = UUID()
    var title: String
}

struct MovieEdit: View {
    @Binding var movie: Movie
    var onCancel: () -> Void = {}
    var onSave: () -> Void = {}

    var body: some View {
        NavigationView {
            TextField("Title", text: .init(get: { movie.title }, set: { movie.title = $0 }))
                .navigationBarTitle("Details", displayMode: .inline)
                .toolbar {
                    ToolbarItem(placement: .cancellationAction) {
                        Button("Cancel", action: onCancel)
                    }
                    ToolbarItem(placement: .confirmationAction) {
                        Button("Done", action: onSave)
                    }
                }
        }
    }
}

struct TestView: View {
  
    // Here we store the list of items
  
    @Binding var movies: [Movie]
  
    // Note: usually this gets described as @State var X: Item?, but in practice this only works if
    // the sheet view does not require a binding, which is contrary to how Apple's HIG describe the
    // purpose of sheets as modal views for the purpose of editing
  
    @State var selectedMovie: Binding<Movie>?

    var body: some View {
        List($movies) { $movie in
            HStack {
                Text(movie.title)
                Spacer()
                Text("Edit")
                    .foregroundColor(.accentColor)
                    .onTapGesture {
                        selectedMovie = $movie
                }
            }
        }
        .sheet(item: $selectedMovie) { movie in // movie: Binding<Movie> (optional has been unwrapped)
            var editMovie = movie.wrappedValue  // take a mutable copy so we can cancel editing without altering state
            // pass a custom binding referencing (and updating) the mutable copy
            MovieEdit(movie: .init(get: { editMovie }, set: { editMovie = $0 }),
                onCancel: {
                    selectedMovie = nil         // dismiss the sheet by reverting the binding to nil
                },
                onSave: {
                    // when save is chosen, update the view state with the revised values from the form
                    movie.wrappedValue = editMovie      
                    selectedMovie = nil         // dismiss the sheet
                })
        }
    }
}

struct TestView_Previews: PreviewProvider {
    @State static var movies: [Movie] = [
        Movie(title: "War of the Worlds"),
        Movie(title: "Blazing Saddles"),
        Movie(title: "Gone with the Wind")
    ]

    static var previews: some View {
        TestView(movies: $movies)
    }
}