blob: f1a84b369f782285c87d0250fa5ef5ece290a8b3 [file] [log] [blame]
// 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.
/// This library is used for testing asynchronous tests.
/// If a test is asynchronous, it needs to notify the testing driver
/// about this (otherwise tests may get reported as passing [after main()
/// finished] even if the asynchronous operations fail).
/// Tests which can't use the unittest framework should use the helper functions
/// in this library.
/// This library provides two methods
/// - asyncStart(): Needs to be called before an asynchronous operation is
/// scheduled.
/// - asyncEnd(): Needs to be called as soon as the asynchronous operation
/// ended.
/// After the last asyncStart() called was matched with a corresponding
/// asyncEnd() call, the testing driver will be notified that the tests is done.
library async_helper;
// TODO(kustermann): This is problematic because we rely on a working
// 'dart:isolate' (i.e. it is in particular problematic with dart2js).
// It would be nice if we could use a different mechanism for different
// runtimes.
import 'dart:isolate';
bool _initialized = false;
ReceivePort _port = null;
int _asyncLevel = 0;
Exception _buildException(String msg) {
return new Exception('Fatal: $msg. This is most likely a bug in your test.');
void asyncStart() {
if (_initialized && _asyncLevel == 0) {
throw _buildException('asyncStart() was called even though we are done '
'with testing.');
if (!_initialized) {
_initialized = true;
_port = new ReceivePort();
void asyncEnd() {
if (_asyncLevel <= 0) {
if (!_initialized) {
throw _buildException('asyncEnd() was called before asyncStart().');
} else {
throw _buildException('asyncEnd() was called more often than '
if (_asyncLevel == 0) {
_port = null;