Hilt viewmodel + replace + transition = crash

[Tolriq]

So this is a tricky one.

Navigator(Screen1()) { navigator ->
                        SlideTransition(navigator)
                    }

class Screen1() : AndroidScreen {
    @Composable
    override fun Content() {
            val viewModel = getViewModel<Screen1ViewModel>()
            ....
            LocalNavigator.currentOrThrow.replace(Screen2())
    }
}

Will lead to a crash

    java.lang.IllegalArgumentException: SavedStateProvider with the given key is already registered
        at androidx.savedstate.SavedStateRegistry.registerSavedStateProvider(SavedStateRegistry.java:111)
        at androidx.lifecycle.SavedStateHandleController.attachToLifecycle(SavedStateHandleController.java:50)
        at androidx.lifecycle.SavedStateHandleController.create(SavedStateHandleController.java:70)
        at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:67)
        at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:84)
        at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:109)

From a quick look the viewmodel is properly cleared, but it seems Voyager tries to re access the SaveStateProvider later with the same key (obviously as it's the same composable).

There's no issue without enabling transitions, so this looks like some wrong order of calls, whatever access the savestate during the transition should do it before the full removal of the composable to avoid trying to reuse the key.
There's also no problem when just pushing a new screen. This works without using hitviewmodel.

[Tolriq]

After looking more into this, this is a more general issue about auto dispose and transitions.

So this probably becomes more a feature request as all the auto dispose / disposal stuff is internal it's not really possible to do it manually at the end of the transition.

Tl;DR is: Auto dispose dispose things too early when using transitions. (And not using auto dispose is not really an option for large apps)

Leading to a few side effects like :

• Full recreation of the view/screen models during the transition (not memory/cpu friendly at that timing). (Leading to this crash that is specific to hilt and viewmodel)
• No disposing of the recreated instances

[programadorthi]

Fixed just putting a missed remember on ViewModel creation here #18. Checkout solution

[adrielcafe]

Fixed on 1.0.0-beta13, feel free to reopen if the issue persists.