Unwrapping an optional presentation store leads to type mismatch.

[jessedoescode]

Hi,

When modeling navigation with an enum:

@Reducer(state: .equatable)
    enum PresentEvent {
        case create(CreateEventFeature)
        case edit(EditEventFeature)
        case saved(SavedEventPresentFeature)
        case unsaved(UnsavedEventFeature)
    }

That is held in the feature's state:

@Presents var presentEvent: PresentEvent.State?

As well as action:

 case presentEvent(PresentationAction<PresentEvent.Action>)

When trying to unwrap it with if let:

if let store = store.scope(state: \.presentEvent, action: \.presentEvent) {
      PresentEventView(store: store)
}

struct PresentEventView: View {
    
    var store: StoreOf<EventsFeature.PresentEvent>
   .....

I get a type mismatch due to the PresentationAction:

Cannot convert value of type 'Store<EventsFeature.PresentEvent.State, PresentationAction<EventsFeature.PresentEvent.Action>>' to expected argument type 'StoreOf<EventsFeature.PresentEvent>' (aka 'Store<EventsFeature.PresentEvent.State, EventsFeature.PresentEvent.Action>')

[mbrandonw]

Hi @jessedoescode, the error is telling you the problem. The store you have constructed has the action PresentationAction<EventsFeature.PresentEvent.Action>, but you are passing it to a view that wants a store with the action EventsFeature.PresentEvent.Action. Notice the extra layer of PresentationAction<…>.

To peel away that layer you can further chain on .presented, which is the case inside PresentationAction that holds onto your type:

if let store = store.scope(state: \.presentEvent, action: \.presentEvent.presented) {
  …
}

[jessedoescode]

@mbrandonw Ahh. Yep, error message is super clear! Just hadn't come across the .presented case like this. Thanks for the quick reply as always and appreciate the hard work!