13_push_notification_testbed.swift

import SwiftUI
import UserNotifications

#if os(iOS)
class AppDelegate : UIResponder, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        registerForPushNotifications()
        UNUserNotificationCenter.current().delegate = self
        return true
    }
}

extension AppDelegate: UNUserNotificationCenterDelegate  {
    // Enabled in the foreground
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification) async -> UNNotificationPresentationOptions {
        [.badge , .banner, .sound]
    }
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse) async {
        // reset app badge
        UIApplication.shared.applicationIconBadgeNumber = 0
    }
}
#endif

#if os(macOS)
class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ notification: Notification) {
        registerForPushNotifications()
        UNUserNotificationCenter.current().delegate = self
    }
}

extension AppDelegate: UNUserNotificationCenterDelegate  {
    // Enabled in the foreground
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification) async -> UNNotificationPresentationOptions {
        [.badge , .banner, .sound]
    }
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse) async {
        // reset app badge
        await MainActor.run{
            NSApp.dockTile.badgeLabel = ""
        }
    }
}

#endif

// register notification(macOS/iOS)
extension AppDelegate {
    func registerForPushNotifications() {
        UNUserNotificationCenter.current()
            .requestAuthorization(options: [.alert, .sound, .badge]) {
                (granted, error) in
                print("Permission granted: \(granted)")
        }
    }
}

@main
struct SimplePushNotificationApp: App {
#if os(iOS)
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
#endif
#if os(macOS)
    @NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
#endif
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

struct ContentView: View {
    var body: some View {
        Text("Push notification testbed")
            .padding()
    }
}