Enhance the Dart unittest library to support multiple invocations in the same application run.

pkg/unittest/test/with_test_environment_test.dart

Index: pkg/unittest/test/with_test_environment_test.dart
diff --git a/pkg/unittest/test/with_test_environment_test.dart b/pkg/unittest/test/with_test_environment_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..57459136ec6d33f73a20a4a53f51633329f6c54d
--- /dev/null
+++ b/pkg/unittest/test/with_test_environment_test.dart
@@ -0,0 +1,50 @@
+// Copyright (c) 2014, 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 unittest.with_test_environment_test;
+
+import 'package:unittest/unittest.dart';
+
+void runUnittests(Function callback) {

[kevmoo, 2014/11/11 21:27:53]

Please use follow the convention of other unittest tests

use metatest

test failure conditions, etc.

[wibling, 2014/11/12 10:33:46]

I am not sure how I should do that?

I am currently testing that I can setup a new test environment and run only the
tests specified in this environment.
I am not really interested in whether the tests pass or not, but rather that I
can setup and run tests in isolation when using this new method.

Do you have any suggestions?

+  unittestConfiguration = new SimpleConfiguration();
+  callback();
+}
+
+void runTests() {
+  test('test', () => expect(2 + 3, equals(5)));
+}
+
+void runTests1() {
+  test('test1', () => expect(4 + 3, equals(7)));
+}
+
+// Test that we can run two different sets of tests in the same run using the
+// withTestEnvironment method.
+void main() {
+  // First check that we cannot call runUnittests twice in a row without it
+  // throwing a StateError due to the unittestConfiguration being set globally
+  // in the first call.
+  try {
+    runUnittests(runTests);
+    runUnittests(runTests1);
+    throw 'Expected this to be unreachable since 2nd run above should throw';
+  } catch(error) {
+    if (error is! StateError)
+      throw error;
+    // expected, silently ignore.
+  }
+
+  // Second test that we can run both when encapsulating in their own private
+  // test environment.
+  withTestEnvironment(() => runUnittests(runTests));
+  withTestEnvironment(() => runUnittests(runTests1));
+
+  // Third test that we can run with two nested test environments.
+  withTestEnvironment(() {
+    runUnittests(runTests);
+    withTestEnvironment(() {
+      runUnittests(runTests1);
+    });
+  });
+}