LibTest/isolate/ReceivePort/asBroadcastStream_A03_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 Stream<T> asBroadcastStream ({void onListen(StreamSubscription<T>
 *   subscription), void onCancel(StreamSubscription<T> subscription)})
 * If onListen is provided, it is called with a subscription-like object that
 * represents the underlying subscription to this stream. It is possible to
 * pause, resume or cancel the subscription during the call to onListen. It
 * is not possible to change the event handlers, including using
 * StreamSubscription.asFuture.
 * @description Checks that onListen callback is called when broadcast stream
 * gets its subscribers and if subscription to underlying stream is cancelled
 * in this callback, no onData events will be fired.
 * @author ilya
 * @author a.semenov@unipro.ru
 */

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

List receivedEvents = [];
bool cancelOk = true;

void finish() {
  new Future.delayed(new Duration(milliseconds: 500), (){
    // give some time for events to be delivered
    if (!cancelOk) {
      Expect.listEquals([], receivedEvents, "Received unexpected events");
    }
    asyncEnd();
  });
}


main() {
  asyncStart();
  var s = IsolateStream.fromIterable([0,1,2,3], onDone:finish);

  Stream b = s.asBroadcastStream(onListen: (subs) {
    cancelOk = (subs.cancel()==null) && cancelOk;
  });

  b.listen((e) {
    receivedEvents.add(e);
  });

  b.listen((e) {
    receivedEvents.add(e);
  });
}