Abort unit tests in the event of async failure while awaiting a future.

pkg/unittest/test/utils.dart

Index: pkg/unittest/test/utils.dart
diff --git a/pkg/unittest/test/utils.dart b/pkg/unittest/test/utils.dart
index 17a8cb62364bf90c449a66456dc538c2dc065361..1c7987df15da4948d0a14e7b41fbe1007c3e1485 100644
--- a/pkg/unittest/test/utils.dart
+++ b/pkg/unittest/test/utils.dart
@@ -5,7 +5,7 @@
 part of unittestTest;
 
 Future _defer(void fn()) {
-  return new Future.sync(fn);
+  return (new Future.value()).then((_) => fn());

[kevmoo, 2014/07/29 19:59:02]

Why not 
  return new Future(() => fn());
?

Could you add a note here explaining the behavior?

[Paul Berry, 2014/07/29 21:54:38]

In fact, this works too and is even shorter:

  return new Future(fn);

I'm not sure exactly what behavior you wanted explained.  Let me know if what
I've added isn't what you're looking for.

 }
 
 String buildStatusString(int passed, int failed, int errors,