| // Copyright (c) 2018, 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<E> asyncExpand<E>(Stream<E> convert(T event)) |
| /// Transforms each element into a sequence of asynchronous events. |
| /// |
| /// Returns a new stream and for each event of this stream, do the following: |
| /// . . . |
| /// - If the call returns null, no further action is taken for the elements. |
| /// |
| /// @description Checks that if convert returns null, no value is put on the |
| /// output stream, just as if it returned an empty stream. |
| /// @author ngl@unipro.ru |
| |
| import "dart:async"; |
| import "dart:io"; |
| import "../http_utils.dart"; |
| import "../../../Utils/expect.dart"; |
| |
| var localhost = InternetAddress.loopbackIPv4; |
| |
| main() async { |
| RawDatagramSocket producer = await RawDatagramSocket.bind(localhost, 0); |
| RawDatagramSocket receiver = await RawDatagramSocket.bind(localhost, 0); |
| List<List<int>> toSend = [[0, 1, 2, 3], [1, 2, 3], [2, 3], [3]]; |
| |
| bool wasSent = |
| await sendDatagram(producer, toSend, localhost, receiver.port); |
| Expect.isTrue(wasSent, "No datagram was sent"); |
| |
| Stream stream = receiver.asyncExpand((e) => null); |
| stream.length.then((value) { |
| Expect.equals(0, value); |
| }); |
| receiver.close(); |
| } |