pkg/unittest: get stackTrace from error directly

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 50 matching lines @@
   Completer _testComplete;
 
   TestCase._internal(this.id, this.description, this.testFunction)
   : currentGroup = _currentContext.fullName,
     setUp = _currentContext.testSetup,
     tearDown = _currentContext.testTeardown;
 
   bool get isComplete => !enabled || result != null;
 
   Function _errorHandler(String stage) => (e) {
-    var stack = getAttachedStackTrace(e);
+    var stack;
+    // TODO(kevmoo): Ideally, getAttachedStackTrace should handle Error as well?
+    // https://code.google.com/p/dart/issues/detail?id=12240
+    if(e is Error) {
+      stack = e.stackTrace;
+    } else {
+      stack = getAttachedStackTrace(e);
+    }
     if (result == null || result == PASS) {
       if (e is TestFailure) {
         fail("$e", stack);
       } else {
         error("$stage failed: Caught $e", stack);
       }
     }
   };
 
   /**
@@ skipping 90 matching lines @@
   void error(String messageText, [stack]) {
     _complete(ERROR, messageText, stack);
   }
 
   void _markCallbackComplete() {
     if (--_callbackFunctionsOutstanding == 0 && !isComplete) {
       pass();
     }
   }
 }