Safe navigation

Fragment.kt

/** Workaround for 'unknown to this navigation controller' error */
fun Fragment.isCurrentDestination(): Boolean {
    val navController = findNavController()
    val currentDestinationId = navController.currentDestination?.id
    val fragmentDestinationId = view?.getTag(R.id.tag_navigation_destination_id) ?: currentDestinationId

    return if (currentDestinationId == fragmentDestinationId) {
        view?.setTag(R.id.tag_navigation_destination_id, fragmentDestinationId)
        true
    } else {
        log.error { "May not navigate: current destination is not the current fragment." }
        false
    }
}

fun Fragment.safeNavigate(action: NavController.() -> Unit) {
    if (isCurrentDestination()) {
        findNavController().apply { action.invoke(this) }
    }
}

...

// In the fragment:

safeNavigate {
    // 'this' is a NavController that's able to navigate without error
    navigate(/** whatever overload you need */)
}