unittest: big cleanup, tightened test semantics

tests/lib/json/json_test.dart

Index: tests/lib/json/json_test.dart
diff --git a/tests/lib/json/json_test.dart b/tests/lib/json/json_test.dart
index b485cd67a3d30dd47bb89b5b34dc0ba55a27e5bc..bb171eaac818aa761b1d15f6a13b0f4af6f801e7 100644
--- a/tests/lib/json/json_test.dart
+++ b/tests/lib/json/json_test.dart
@@ -67,6 +67,7 @@ main() {
                    '"z":"hi","w":{"c":null,"d":true}, "v":null}'),
         equals({"x": {"a":3, "b": -4.5}, "y":[{}],
                    "z":"hi","w":{"c":null,"d":true}, "v":null}));
+  });
 
   test('stringify', () {
     // Scalars.
@@ -130,7 +131,6 @@ main() {
      * we try to stringify something that cannot be converted to json.
      */
     expect(() => json.stringify(new TestClass()), throwsJsonError);
-    });
   });
 
   test('stringify throws if toJson throws', () {