blob: 067fccf8489d053f17b90d0f08d46c456090decc [file] [log] [blame]
// Copyright (c) 2016, 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
import "dart:async";
import "package:expect/expect.dart";
import "package:async_helper/async_helper.dart";
var events = [];
var timer;
ticker(period) async* {
var sc;
sc = new StreamController(onListen: () {
events.add("listen");
timer = new Timer.periodic(period, (_) {
sc.add(null);
});
}, onCancel: () {
events.add("cancel");
timer.cancel();
});
try {
var counter = 0;
await for (var tick in sc.stream) {
counter++;
}
} finally {
events.add("finally");
}
}
void main() {
asyncStart();
events.add("main");
final subscription =
ticker(const Duration(milliseconds: 20)).listen((val) {});
bool cancelFinished = false;
new Timer(const Duration(milliseconds: 100), () async {
// Despite the cancel call below, the stream doesn't stop.
// The async* function is not blocked at any await (since the inner timer
// continuously ticks), but since there/ is no yield-point in the function
// it won't cancel.
new Timer(const Duration(milliseconds: 30), () {
Expect.isFalse(cancelFinished);
Expect.listEquals(["main", "listen", "invoke cancel"], events);
timer.cancel();
asyncEnd();
});
events.add("invoke cancel");
await subscription.cancel();
// This line should never be reached, since the cancel-future doesn't
// complete.
cancelFinished = true;
});
}