main.dart

  import 'dart:async';
  
  // Simulates a slow async initialization
  Future<void> initializeRepositories() async {
    print('  ⏳ initializeRepositories: STARTED');
    await Future.delayed(Duration(seconds: 2));
    print('  ✅ initializeRepositories: DONE');
  }
  
  // Simulates accountManager.run — note: it correctly awaits internally
  Future<void> accountManagerRun(Future<void> Function() action) async {
    print('  accountManager.run: calling action...');
    await action();
    print('  accountManager.run: action finished');
  }
  
  void main() async {
    // Simulate a stream of session ID updates
    final controller = StreamController<String?>();
  
    // ❌ BUG: listen() does NOT await the async callback.
    // The Future returned by the async callback is silently dropped.
    controller.stream.distinct().listen((sessionId) async {
      print('\n🔔 Event received: sessionId=$sessionId');
  
      if (sessionId != null) {
        // This await only suspends THIS callback's microtask.
        // listen() itself has already returned void — nobody waits for this.
        await accountManagerRun(() async {
          await initializeRepositories();
        });
      }
  
      print('🏁 Callback for $sessionId thinks it is done.');
    });
  
    // Fire two events in quick succession
    print('>>> Emitting event 1: "user-abc"');
    controller.add('user-abc');
  
    print('>>> Emitting event 2: "user-xyz"');
    controller.add('user-xyz');
  
    // This runs IMMEDIATELY — it does NOT wait for the listen callbacks
    print('\n>>> Main continues WITHOUT waiting for initialization!');
    print('>>> If code here assumes repos are initialized, 💥 RACE CONDITION.\n');
  
    // Give time for the async callbacks to actually complete
    await Future.delayed(Duration(seconds: 5));
  
    print('\n--- Timeline shows events interleaved, not sequential ---');
    await controller.close();
  }