pkg/unittest: fix test after last change

pkg/unittest/test/with_test_environment_test.dart

 // 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 'dart:async';
 import 'package:unittest/unittest.dart';
 
 class TestConfiguration extends SimpleConfiguration {
@@ skipping 15 matching lines @@
         .then(_completer.complete)
         .catchError(_completer.completeError);
   }
 
   bool checkIfTestRan(String testName) {
     return _results.any((test) => test.description == testName);
   }
 }
 
 Future runUnittests(Function callback) {
-  var config = new TestConfiguration();
-  unittestConfiguration = config;
+  TestConfiguration config = unittestConfiguration = new TestConfiguration();
   callback();
 
   return config.done;
 }
 
 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';
-  } on StateError catch (error) {
-    // expected, silently ignore.
-  }
+  // Check that setting config a second time does not change the configuration
+  runUnittests(runTests);
+  var config = unittestConfiguration;
+  runUnittests(runTests1);
+  expect(config, unittestConfiguration);
 
   // Test that we can run both when encapsulating in their own private test
   // environment. Also test that the tests actually running are the ones
   // scheduled in the runTests/runTests1 methods.
   withTestEnvironment(() {
     runUnittests(runTests).whenComplete(() {
       TestConfiguration config = unittestConfiguration;
       expect(config.checkIfTestRan('test'), true);
       expect(config.checkIfTestRan('test1'), false);
     });
   });
   withTestEnvironment(() {
     runUnittests(runTests1).whenComplete(() {
       TestConfiguration config = unittestConfiguration;
       expect(config.checkIfTestRan('test'), false);
       expect(config.checkIfTestRan('test1'), true);
     });
   });
 
   // Third test that we can run with two nested test environments.
   withTestEnvironment(() {
     runUnittests(runTests);
     withTestEnvironment(() {
       runUnittests(runTests1);
     });
   });
 }