pkg/unittest: Run each test in a Zone

pkg/unittest/lib/src/spread_args_helper.dart

 part of unittest;
 
 /** Simulates spread arguments using named arguments. */
 // TODO(sigmund): remove this class and simply use a closure with named
 // arguments (if still applicable).
 class _SpreadArgsHelper {
   final Function callback;
   final int minExpectedCalls;
   final int maxExpectedCalls;
   final Function isDone;
@@ skipping 102 matching lines @@
 
   invoke2(arg1, arg2) {
     return _guardAsync(
         () {
           if (shouldCallBack()) {
             return callback(arg1, arg2);
           }
         },
         after, testCase);
   }
+
+  _guardAsync(Function tryBody, Function finallyBody, TestCase testCase) {

[Siggi Cherem (dart-lang), 2014/02/04 02:20:05]

I thought we were going to get rid of this too (since the invoke0/1/2 are
created inside the zone, they should be guarded)

[kevmoo, 2014/02/04 02:26:18]

This is still used by the expectAsync logic. I'm leaving it in for the time
being while I peel the onion

[Siggi Cherem (dart-lang), 2014/02/04 02:42:01]

I meant, I thought you were going to get rid of it by changing expectAsync
above.

No worries, one layer at a time sounds good too :)

+    assert(testCase != null);
+    try {
+      return tryBody();
+    } catch (e, trace) {
+      _registerException(testCase, e, trace);
+    } finally {
+      if (finallyBody != null) finallyBody();
+    }
+  }
 }