LibTest/async/StreamController/StreamController.broadcast_A07_t02.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 listener
 * ends its subscription.
 * @author kaigorodov
 */
import "dart:async";
import "../../../Utils/expect.dart";

main() {
  bool onCancelCalled = false;
  asyncStart();
  StreamController controller = new StreamController.broadcast(
    onCancel: () {
      onCancelCalled = true;
      asyncEnd();
    }
  );

  Expect.isFalse(onCancelCalled);
  StreamSubscription subs = controller.stream.listen((event) {});
  subs.cancel();
}