tests/lib/async/stream_periodic3_test.dart

// Copyright (c) 2013, 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.

// Test merging streams.
library dart.test.stream_from_iterable;

import "dart:async";
import '../../../pkg/unittest/lib/unittest.dart';

// The stopwatch is more precise than the Timer. It can happen that
// the TIMEOUT triggers *slightly* too early on the VM. So we add a millisecond
// as safetymargin.
// Some browsers (Firefox and IE so far) can trigger too early. So we add more
// 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) ? 5 : 1;

main() {
  test("stream-periodic3", () {
    Stopwatch watch = new Stopwatch()..start();
    Stream stream = new Stream.periodic(const Duration(milliseconds: 1),
                                        (x) => x);
    stream.take(10).listen((_) { }, onDone: expectAsync0(() {
      int millis = watch.elapsedMilliseconds + safetyMargin;
      expect(millis, greaterThan(10));
    }));
  });
}