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);
  });
}