Add a test runner executable.

test/utils.dart

 // Copyright (c) 2015, 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 unittest.test.utils;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:unittest/src/live_test.dart';
+import 'package:unittest/src/load_exception.dart';
 import 'package:unittest/src/remote_exception.dart';
 import 'package:unittest/src/state.dart';
 import 'package:unittest/unittest.dart';
 
 // The last state change detected via [expectStates].
 State lastState;
 
 /// Asserts that exactly [states] will be emitted via [liveTest.onStateChange].
 ///
 /// The most recent emitted state is stored in [_lastState].
@@ skipping 43 matching lines @@
 /// Returns a matcher that matches a [TestFailure] with the given [message].
 Matcher isTestFailure(String message) => predicate(
     (error) => error is TestFailure && error.message == message,
     'is a TestFailure with message "$message"');
 
 /// Returns a matcher that matches a [RemoteException] with the given [message].
 Matcher isRemoteException(String message) => predicate(
     (error) => error is RemoteException && error.message == message,
     'is a RemoteException with message "$message"');
 
+/// Returns a matcher that matches a [LoadException] with the given [message].
+Matcher isLoadException(String message) => predicate(
+    (error) => error is LoadException && error.innerError == message,
+    'is a LoadException with message "$message"');
+
 /// Returns a [Future] that completes after pumping the event queue [times]
 /// times.
 ///
 /// By default, this should pump the event queue enough times to allow any code
 /// to run, as long as it's not waiting on some external event.
 Future pumpEventQueue([int times=20]) {
   if (times == 0) return new Future.value();
   // Use [new Future] future to allow microtask events to finish. The [new
   // Future.value] constructor uses scheduleMicrotask itself and would therefore
   // not wait for microtask callbacks that are scheduled after invoking this
   // method.
   return new Future(() => pumpEventQueue(times - 1));
 }