Files
sdk/tests/lib/async/timer_repeat_test.dart
T
Robert Nystrom a2b556b937 Migrate lib_2/async to NNBD.
Change-Id: Ia5c41dda6503e1fbb8cc6099835d07588425e2ba
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128310
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
2020-01-09 22:04:37 +00:00

45 lines
1.3 KiB
Dart

// Copyright (c) 2012, 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.
library timer_repeat_test;
import 'dart:async';
import 'package:expect/expect.dart';
const Duration TIMEOUT = const Duration(milliseconds: 500);
const int ITERATIONS = 5;
late Timer timer;
Stopwatch stopwatch = new Stopwatch();
int iteration = 0;
// Some browsers (Firefox and IE so far) can trigger too early. Add a safety
// margin. We use identical(1, 1.0) as an easy way to know if the test is
// compiled by dart2js.
int get safetyMargin => identical(1, 1.0) ? 100 : 0;
var completer = new Completer();
void timeoutHandler(Timer timer) {
iteration++;
Expect.isTrue(iteration <= ITERATIONS);
if (iteration == ITERATIONS) {
// When we are done with all of the iterations, we expect a
// certain amount of time to have passed. Checking the time on
// each iteration doesn't work because the timeoutHandler runs
// concurrently with the periodic timer.
Expect.isTrue(stopwatch.elapsedMilliseconds + safetyMargin >=
ITERATIONS * TIMEOUT.inMilliseconds);
timer.cancel();
completer.complete();
}
}
main() {
stopwatch.start();
timer = new Timer.periodic(TIMEOUT, timeoutHandler);
return completer.future;
}