UIStateKs not synchronized with UIState class

[aleksey-ho]

I have this code that works in debug environment, but crashes in testflight.

    private val _purchaseResult = MutableStateFlow<UIState<UserPremium>>(UIState.Empty)
    val purchaseResult = _purchaseResult.cStateFlow()

in BasePurchaiseScreen.swift:

struct BasePurchaiseScreen<Content> : View where Content : View {
  @StateObject var vm = PurchaseVM()
...
extension PurchaseVM {
  var purchaseResultBind: UIStateKs<UserPremium> {
    get {
      return self.state(
        \.purchaseResult,
         equals: { $0 === $1 },
         mapper: { UIStateKs($0) }
      )
    }
  }
}

It did work, but somehow it started crashing when I call vm.purchaseResultBind with error:

Crashed: com.apple.main-thread EXC_BREAKPOINT 0x00000001a0ab58c0 0 libswiftCore.dylib 0x398c0 assertionFailure(:_:file:line:flags:) + 264 1 myapp 0x7c850 MPLPurchaseVM.purchaseResultBind.getter + 80 (BasePurchaiseScreen.swift:80) 2 myapp 0x7bb48 closure #1 in BasePurchaiseScreen.body.getter + 42 (BasePurchaiseScreen.swift:42) 3 SwiftUI 0x181e58 OUTLINED_FUNCTION_1147 + 1244 4 myapp 0x7b35c BasePurchaiseScreen.body.getter + 53 (BasePurchaiseScreen.swift:53) 5 myapp 0x7cad8 protocol witness for View.body.getter in conformance BasePurchaiseScreen + 4366256856 (:4366256856) 6 SwiftUI 0x202528 dynamic_cast_existential_0_superclass_conditional + 24428 7 SwiftUI 0x24d738 -[UIScrollView(SwiftUI) _swiftui_adjustsContentInsetWhenScrollDisabled] + 31980 8 SwiftUI 0x24b3bc -[UIScrollView(SwiftUI) _swiftui_adjustsContentInsetWhenScrollDisabled] + 22896 9 SwiftUI 0x1fdb30 dynamic_cast_existential_0_superclass_conditional + 5492 10 AttributeGraph 0x9010 AG::Graph::UpdateStack::update() + 512 11 AttributeGraph 0x8bfc AG::Graph::update_attribute(AG::data::ptr, unsigned int) + 424 12 AttributeGraph 0x2cc0 AG::Graph::input_value_ref_slow(AG::data::ptr, AG::AttributeID, unsigned int, unsigned int, AGSwiftMetadata const*, unsigned char&, long) + 720 ....

I also found "MultiPlatformLibrarySwift/myapp_shared.swift:37: Fatal error: UIStateKs not synchronized with UIState class" message in logs from generated UIStateKs.

Any idea to fix this crash?

your generated swift code outdated. in kotlin source you have some new cases in sealed, but in swift code this cases not used yet

[aleksey-ho]

@Alex009, Hi, Thank you for quick reply! Here's my sealed class UIState and UserPremium used in MutableStateFlow<UIState>(UIState.Empty)

sealed class UIState<out T> {
    object Loading : UIState<Nothing>()
    object Empty : UIState<Nothing>()
    data class Data<T>(val value: T) : UIState<T>()
    data class Error(val throwable: Throwable) : UIState<Nothing>()
}

data class UserPremium(val isActive: Boolean, val state: SubscriptionState)

enum class SubscriptionState {
    AVAILABLE, BILLING_ISSUE, CANCELLED, ERROR
}

and generated UIStateKs:

public enum UIStateKs<T : AnyObject> {

  case data(UIStateData<T>)
  case empty
  case error(UIStateError)
  case loading

  public var sealed: UIState<T> {
    switch self {
    case .data(let obj):
      return obj as MultiPlatformLibrary.UIState<T>
    case .empty:
      return MultiPlatformLibrary.UIStateEmpty() as! MultiPlatformLibrary.UIState<T>
    case .error(let obj):
      return obj as! MultiPlatformLibrary.UIState<T>
    case .loading:
      return MultiPlatformLibrary.UIStateLoading() as! MultiPlatformLibrary.UIState<T>
    }
  }

  public init(_ obj: UIState<T>) {
    if let obj = obj as? MultiPlatformLibrary.UIStateData<T> {
      self = .data(obj)
    } else if obj is MultiPlatformLibrary.UIStateEmpty {
      self = .empty
    } else if let obj = obj as? MultiPlatformLibrary.UIStateError {
      self = .error(obj)
    } else if obj is MultiPlatformLibrary.UIStateLoading {
      self = .loading
    } else {
      fatalError("UIStateKs not synchronized with UIState class")
    }
  }

}

is there anything I need to change? I's not clear for me why is it working on simulator but not in festflight build

[Alex009]

strange. what value you have in UIState<T> when fatalError throws?

[aleksey-ho]

Unfortunately, I can't get the value in debug environment. It crashes only in testflight build