Crash when working with navigation api and NavigationSplitView

[marcuswu0814]

Hi @mbrandonw, this is my reproduce project that crash when building my features with NavigationSplitView and TCA navigation api (maybe cause by NavigationPath).

The project:

• Root with a NavigationSplitView(sideBar:detail:) two columns mode
• Three tab, A and B build with a NavigationStack(path:) api, and using the pattern like Reducer(state: .equatable) enum Path {}
• C Tab build with a pure Text("...")

Problems:

• If switch A -> C -> B, just ok
• Switch from A -> B directly, crash. SwiftUI/NavigationColumnState.swift:560: Fatal error: 'try!' expression unexpectedly raised an error: SwiftUI.AnyNavigationPath.Error.comparisonTypeMismatch

I'm not sure it was a best practice to use NavigationSplitView with TCA like my project, if a better solution exist, please give some advice for me. 🙏

[marcuswu0814]

I try to add a workaround for the crash.

I replace the NavigationLink(title:value:) with a wrapper of a pure Button like:

@ViewBuilder
func navigationLink(
    _ title: String,
    value: Feature.State.Tab
) -> some View {
    Button(title) {
        store.send(.switchTab(value))
    }
    .tag(value)
}

and mutating the selection state via action, the crash just gone, but still want to know how to fix the issue and way to work NavigationSplitView more elegance with TCA.

[mbrandonw]

Hi @marcuswu0814, I don't think NavigationSplitView is meant to be used in the way you have structured things above. Each of your "tab" views have their own NavigationStack, and that isn't correct. There should only be one single NavigationStack in the detail trailing closure:

NavigationSplitView {
  …
} detail: {
  NavigationStack(path: …) {
    …
  }
}

I recommend looking at Apple's Cookbook demo app for more information on how to properly use NavigationSplitView.