Robert Nystrom
fc1b1ecc71
Change-Id: Idbcc965a27e9ffeedf5e0a1068b019de4193070f Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/127745 Commit-Queue: Bob Nystrom <rnystrom@google.com> Reviewed-by: Alexander Thomas <athom@google.com>
50 lines
1.2 KiB
Dart
50 lines
1.2 KiB
Dart
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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import "dart:async";
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import "package:expect/expect.dart";
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import "package:async_helper/async_helper.dart";
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var events = [];
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ticker() async* {
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var sc;
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var sentTickCount = 0;
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sc = new StreamController(onListen: () {
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events.add("listen");
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}, onCancel: () {
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events.add("cancel");
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});
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try {
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var counter = 0;
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await for (var tick in sc.stream) {
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counter++;
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}
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} finally {
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events.add("finally");
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}
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}
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void main() {
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asyncStart();
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events.add("main");
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final subscription = ticker().listen((val) {});
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bool cancelFinished = false;
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// Cancel the subscription.
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// The async* function is blocked on an `await` (the inner stream) and won't
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// be able to complete.
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Timer.run(() {
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events.add("invoke cancel");
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subscription.cancel().then((_) => cancelFinished = true);
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});
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new Timer(const Duration(milliseconds: 100), () {
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Expect.isFalse(cancelFinished);
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Expect.listEquals(["main", "listen", "invoke cancel"], events);
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asyncEnd();
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});
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}
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