blob: 33d8822eafbf1404b5721099175142e3c1ee6378 [file] [log] [blame]
// Copyright (c) 2017, 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 Future<bool> isEmpty
/// Reports whether this stream contains any elements.
///
/// Stops listening to the stream after the first element has been received.
///
/// Internally the method cancels its subscription after the first element.
/// This means that single-subscription (non-broadcast) streams are closed and
/// cannot be reused after a call to this getter.
///
/// @description Checks that the [isEmpty] returns the Future<bool>.
/// @author ngl@unipro.ru
import "dart:async";
import "dart:io";
import "../../../Utils/expect.dart";
main() {
HttpServer.bind("127.0.0.1", 0).then((server) {
server.listen((request) {
WebSocketTransformer
.upgrade(request)
.then((websocket) {
Expect.isTrue(websocket.isEmpty is Future<bool>);
websocket.close();
});
});
var webs = WebSocket.connect("ws://127.0.0.1:${server.port}/");
webs.then((client) {
bool called = false;
client.isEmpty.then((value) {
Expect.isTrue(value);
called = true;
});
client.close().then((_) async {
await server.close();
Expect.isTrue(called);
});
});
});
}