Crash when used with rearrangeable SwiftUI List

[okla]

I'm using var items: IdentifiedArrayOf<MyType> with SwiftUI's List($items, editActions: .all) and once I rearrange any element in the list the app crashes with Precondition failed: Element identity must remain constant

[okla]

Using a workaround for now

List {
  ForEach($items) { ... }
    .onMove {
      items.move(fromOffsets: $0, toOffset: $1)
    }
}

[stephencelis]

@okla Can you provide a full reproduction of the original issue you were having for us to work with? Right now we don't really have much to go off of. We do have a test for move(fromOffsets:toOffset:), though:

https://github.com/pointfreeco/swift-identified-collections/blob/main/Tests/IdentifiedCollectionsTests/IdentifiedArrayTests.swift#L219

[okla]

@stephencelis Here's the full reproduction code

import SwiftUI
import IdentifiedCollections

struct Item: Identifiable {
  var id = UUID()
}

struct ContentView: View {
  @State var items: IdentifiedArray = [Item(), Item(), Item()]

  var body: some View {
    List($items, editActions: .all) { item in
      Text("\(item.wrappedValue.id)")
    }
  }
}

@main
struct testApp: App {
  var body: some Scene {
    WindowGroup {
      ContentView()
    }
  }
}

[stephencelis]

@okla Thanks! Can you try this PR's branch and see if it fixes the issue for you?

https://github.com/pointfreeco/swift-identified-collections/pull/48

[okla]

@stephencelis Works fine now!