IssueTracker

Component used: Navigation

Version used: 2.8.0-beta01

Devices/Android versions reproduced on: all

When specifying the startDestination for a NavHost, if the destination class is instantiated with an empty list for one of its properties, the app will crash.

Repro code:

@Composable
fun Content() {
   val navController = rememberNavController()
   NavHost(navController = navController, startDestination = Home(usernames = emptyList())) {
       composable<Home> { backStackEntry ->
           val home: Home = backStackEntry.toRoute()
           for (username in home.usernames) {
               Text(username)
           }
       }
   }
}

@Serializable
data class Home(
   val usernames: List<String>,
)

Expected outcome:

App runs and displays an empty screen

Actual outcome:

App crashes with the following error in logcat:

java.lang.IllegalArgumentException: navigation destination com.example.hellonavigation.Home is not a direct child of this NavGraph

Possibly related to: https://b.corp.google.com/issues/339481310