Fix for returned Futures in unittest

pkg/unittest/lib/src/test_case.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.
 
 part of unittest;
 
 /**
  * Represents the state for an individual unit test.
  *
  * Create by calling [test] or [solo_test].
@@ skipping 64 matching lines @@
 
   Future _runTest() {
     _prepTest();
     // Increment/decrement callbackFunctionsOutstanding to prevent
     // synchronous 'async' callbacks from causing the  test to be
     // marked as complete before the body is completely executed.
     ++_callbackFunctionsOutstanding;
     var f = testFunction();
     --_callbackFunctionsOutstanding;
     if (f is Future) {
-      f.then((_) => _finishTest())
+      return f.then((_) => _finishTest())
        .catchError((e) => fail("${e.error}"));
-      return f;
     } else {
       _finishTest();
       return null;
     }
   }
 
   void _finishTest() {
     if (result == null && _callbackFunctionsOutstanding == 0) {
       pass();
     }
@@ skipping 105 matching lines @@
   void error(String messageText, [String stack = '']) {
     _complete(ERROR, messageText, stack);
   }
 
   void _markCallbackComplete() {
     if (--_callbackFunctionsOutstanding == 0 && !isComplete) {
       pass();
     }
   }
 }