Using BGTaskScheduler API with new iOS 14 App. How to register tasks without an AppDelegate?

Question

I'm using the BGTaskScheduler API to register background tasks in my iOS 14 app which is using the new App as @Main instead of an AppDelegate. I thought we were to use scenePhase as below to mimic the previous function of didFinishLaunching in AppDelegate but the below causes a crash: *** Assertion failure in -[BGTaskScheduler _unsafe_registerForTaskWithIdentifier:usingQueue:launchHandler:], BGTaskScheduler.m:185 2020-12-01 12:53:40.645091-0500 newFitnessApp[13487:1952133] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'All launch handlers must be registered before application finishes launching' How to implement BGTaskScheduler?

@main
struct newFitnessAppApp: App {
    
    @Environment(\.scenePhase) var scenePhase
    
    //Launch Count (for requesting reviews and to show tutorial)
    //var launchCount = UserDefaults.standard.integer(forKey: TrackerConstants.launchCountKey)
    //var testMode = true
    //@Environment(\.scenePhase) private var phase
    let trackerDataStore = TrackerDataStore(workoutLoader: HealthKitWorkoutLoader())
    
    var body: some Scene {
        WindowGroup {
            AppRootView().environmentObject(trackerDataStore)
        }
        .onChange(of: scenePhase) { newScenePhase in
            switch newScenePhase {
            case .active:
                print("App is active")
                registerBackgroundTasks()

Answer 1

Try to do it in init

@main
struct newFitnessAppApp: App {

   init() {
      registerBackgroundTasks()
   }

// ... other code
}

or use AppDelegate adapter to do this in delegate callback https://stackoverflow.com/a/62538373/12299030