throw when group or test is called while unittest system is running

pkg/unittest/test/unittest_invalid_ops_test.dart

Index: pkg/unittest/test/unittest_invalid_ops_test.dart
diff --git a/pkg/unittest/test/unittest_invalid_ops_test.dart b/pkg/unittest/test/unittest_invalid_ops_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..e70d8a8815331e057f0b300297850dd52a5d0ab9
--- /dev/null
+++ b/pkg/unittest/test/unittest_invalid_ops_test.dart
@@ -0,0 +1,27 @@
+// 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.
+
+library unittestTest;
+import 'dart:isolate';
+import 'dart:async';
+import 'package:unittest/unittest.dart';
+
+part 'unittest_test_utils.dart';
+
+var testName = 'invalid ops throw while test is running';
+
+var testFunction = (_) {
+  test(testName, () {
+    expect(() => test('test', () {}), throwsStateError);
+    expect(() => solo_test('test', () {}), throwsStateError);
+    expect(() => group('test', () {}), throwsStateError);
+    expect(() => solo_group('test', () {}), throwsStateError);
+    expect(() => setUp(() {}), throwsStateError);
+    expect(() => tearDown(() {}), throwsStateError);
+    expect(() => runTests(), throwsStateError);
+    expect(() => rerunTests(), throwsStateError);
+  });
+};
+
+var expected = buildStatusString(1, 0, 0, testName);