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.

// @dart = 2.9

/// @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();
}