LibTest/async/StreamController/StreamController.broadcast_A07_t03.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// @assertion StreamController.broadcast({void onListen(), void onCancel(),
///                                       bool sync: false})
/// The onListen callback is called when the first listener is subscribed,
/// and the onCancel is called when there are no longer any active listeners.
///
/// @description Checks that the onCancel function is called when the last
/// listener unsubscribes.
/// @author a.semenov@unipro.ru

import "dart:async";
import "../../../Utils/expect.dart";

main() {
  int onCancelCallCount = 0;
  asyncMultiStart(6);
  StreamController? controller;
  controller = new StreamController.broadcast(
    onCancel: () {
      onCancelCallCount++;
      Expect.equals(1, onCancelCallCount);
      asyncEnd();
      controller?.close();
    }
  );
  List<StreamSubscription> subscriptions = new List.generate(
    5,
    (_) => controller!.stream.listen((event) {})
  );

  int i = 0, k = 0;
  new Timer.periodic(durationInMilliseconds(100), (Timer timer) {
    new Future.value(subscriptions[i].cancel()).then(
      (_) {
        Expect.equals((++k < 5) ? 0 : 1, onCancelCallCount);
        asyncEnd();
      }
    );
    i++;
    if (i==5) {
      timer.cancel();
    }
  });
}