SwiftData + PassColor causes __NSCFNumber to NSString casting crash

[mohalibou]

When using SwiftData + PassColor, I encounter a consistent crash:

Could not cast value of type '__NSCFNumber' to 'NSString'

This happens when saving a model with an optional PassColor? and then fetching it back.

The crash seems to occur here.

Below is a code sample you can copy/paste that will allow you to easily reproduce the same issue:

import PassCore
import SwiftUI
import SwiftData

@Model
final class WalletPass {
    var name: String
    var labelColor: PassColor?

    init(name: String, labelColor: PassColor?) {
        self.name = name
        self.labelColor = labelColor
    }
}

struct ContentView: View {
    @Environment(\.modelContext) private var modelContext
    @Query private var passes: [WalletPass]

    var body: some View {
        List {
            Button("Insert Pass") {
                let pass = WalletPass(
                    name: "Some Pass",
                    labelColor: .init(r: 255, g: 0, b: 0)
                )
                modelContext.insert(pass)
                try? modelContext.save()
            }
            ForEach(passes) { pass in
                Text(pass.name)
            }
        }
    }
}

@main
struct TestingPassColorCrashApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        .modelContainer(for: [WalletPass.self])
    }
}

[hiimtmac]

Hey there, I recall having the same problem. AFAICT, SwiftData doesn't like/doesn't properly use a custom codable implementation. So in my app with SwiftData I had to make a wrapper to actually persist the color (and any other object with a custom codable impl)

// SwiftData could not handle PassCore's `PassColor`, encoding/decoding did not work
struct SwiftDataPassColor: Codable { // No custom Codable implementation
    let r: Int
    let g: Int
    let b: Int

    init(color: PassColor) { // use this when going from pass-kit to your app
       self. r = color.r
        self.g = color.g
        self.b = color.b
    }

    func generate() -> PassColor { // use this when going from your app back to pass-kit
        .init(r: r, g: g, b: b)
    }
}

// Use it in your model
@Model
final class WalletPass {
    var name: String
    var labelColor: SwiftDataPassColor?

    init(name: String, labelColor: SwiftDataPassColor?) {
        self.name = name
        self.labelColor = labelColor
    }
}

There might be another way or something Im missing but this is what I had to do anyways! Hopefully this helps.

[mohalibou]

I see. I guess I'll have to go down that route. I can try to see if maybe there's a way to get it to work, but in any case, I appreciate your time.