Description

I I have an iPad Split View with a list of items that trigger changes in an IfLetStore, and the state changes as expected. However, the child view inside the IfLetStore does not update accordingly.

Checklist

[ ] I have determined whether this bug is also reproducible in a vanilla SwiftUI project.
[ ] If possible, I've reproduced the issue using the main branch of this package.
[X] This issue hasn't been addressed in an existing GitHub issue or discussion.

Expected behavior

When selecting a new store, both the store and its children should update.

Actual behavior

Selecting the first store updates both the store and the children.
Selecting another store updates just the store.
When the store is set to nil and selected again, both the store and the children are updated.

https://github.com/user-attachments/assets/fd8d27a8-898d-44fc-a4bd-7ae74f019382

Steps to reproduce

I made simple app to reproduce the bug, here is the code:

import ComposableArchitecture import SwiftUI

struct MainReducer: Reducer { struct State: Equatable { var firstChildState: FirstChildReducer.State? }

enum Action: Equatable {
    case firstChildAction(FirstChildReducer.Action)
    case selectFirstChildState(FirstChildReducer.State?)
}

var body: some ReducerOf<Self> {
    Reduce { state, action in
        switch action {
        case let .selectFirstChildState(newState):
            state.firstChildState = newState
            return .none

        case .firstChildAction(.secondChildAction(.playButtonTapped)):
            return .send(.selectFirstChildState(nil))

        case .firstChildAction:
            return .none
        }
    }
    .ifLet(\.firstChildState, action: /Action.firstChildAction) {
        FirstChildReducer()
    }
}

}

struct MainView: View { var store: StoreOf

var body: some View {
    WithViewStore(store, observe: { $0 }) { viewStore in
        HStack {
            List {
                ForEach(1 ..< 5, id: \.self) { num in
                    Button {
                        viewStore.send(.selectFirstChildState(.init(number: num)))
                    } label: {
                        Text("Num: \(num)")
                    }
                }
            }
            if viewStore.firstChildState != nil {
                IfLetStore(
                    store
                        .scope(state: \.firstChildState, action: MainReducer.Action.firstChildAction)
                ) { store in
                    FirstChildView(store: store)
                        .frame(width: UIScreen.main.bounds.width * 0.66)
                }
            } else {
                Text("Select State")
                    .frame(width: UIScreen.main.bounds.width * 0.66)
            }
        }
    }
}

}

struct FirstChildView: View { var store: StoreOf

var body: some View {
    WithViewStore(store, observe: { $0 }) { viewStore in
        VStack {
            SecondChildView(
                store: store
                    .scope(state: \.secondChildState, action: FirstChildReducer.Action.secondChildAction)
            )
            Spacer()
            Text("Hello, World! \(viewStore.number)")
                .font(.system(size: 30, weight: .bold))
            Spacer()
        }
    }
}

}

struct FirstChildReducer: Reducer { struct State: Equatable, Identifiable { var id: UUID = .init() var number: Int

    var secondChildState = SecondChildReducer.State()
}

enum Action: Equatable {
    case secondChildAction(SecondChildReducer.Action)
}

var body: some ReducerOf<Self> {
    Scope(state: \.secondChildState, action: /Action.secondChildAction) {
        SecondChildReducer()
    }

    Reduce { _, action in
        switch action {
        case .secondChildAction:
            return .none
        }
    }
}

}

struct SecondChildView: View { var store: StoreOf

var body: some View {
    WithViewStore(store, observe: { $0 }) { viewStore in
        ZStack {
            Rectangle()
                .frame(height: UIScreen.main.bounds.height * 0.33)
            Button {
                viewStore.send(.playButtonTapped)
            } label: {
                Image(systemName: "play")
                    .resizable()
                    .frame(width: 36, height: 40)
                    .foregroundStyle(Color.white)
                    .rotationEffect(.degrees(viewStore.angle))
                    .animation(.easeInOut(duration: 1), value: viewStore.angle)
            }
            Spacer()
        }
        .onAppear {
            viewStore.send(.angleChanged(to: 0))
        }
    }
}

}

struct SecondChildReducer: Reducer { struct State: Equatable { var angle = 90.0 }

enum Action: Equatable {
    case playButtonTapped
    case angleChanged(to: Double)
}

var body: some ReducerOf<Self> {
    Reduce { state, action in
        switch action {
        case .playButtonTapped:
            return .none
        case let .angleChanged(newAngle):
            state.angle = newAngle
            return .none
        }
    }
}

}

Preview {

MainView(store: Store(initialState: MainReducer.State(), reducer: {}))

}

The Composable Architecture version information

from: 1.5.0

Destination operating system

iOS 16.0

Xcode version information

15.2

Swift Compiler version information

swift-driver version: 1.87.3 Apple Swift version 5.9.2 (swiftlang-5.9.2.2.56 clang-1500.1.0.2.5)
Target: arm64-apple-macosx14.0

pointfreeco / swift-composable-architecture

The child of IfLetStore doesn't update together with the store. #3242