LibTest/async/StreamController/StreamController_A04_t01.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({void onListen(), void onPause(),
 *                  void onResume(), dynamic onCancel(), bool sync: false})
 * The onPause function is called when the stream becomes paused.
 *
 * @description Checks that the onPause function is called when the stream
 * becomes paused.
 * @author kaigorodov
 */
import "dart:async";
import "../../../Utils/expect.dart";

main() {
  bool onPauseCalled = false;
  StreamController controller = new StreamController(
    onPause: () {onPauseCalled = true;}
  );

  StreamSubscription subs = controller.stream.listen((event) {});
  controller.add(1);
  Expect.isFalse(onPauseCalled);

  subs.pause();
  Expect.isTrue(onPauseCalled);
}