Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/context_manager_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 test.context.directory.manager;
 
 import 'dart:collection';
-import 'dart:io' as io;
 
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/source/error_processor.dart';
 import 'package:analyzer/src/context/builder.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/services/lint.dart';
 import 'package:analyzer/src/task/options.dart'
     show CONFIGURED_ERROR_PROCESSORS;
 import 'package:analyzer/src/util/glob.dart';
 import 'package:linter/src/plugin/linter_plugin.dart';
 import 'package:linter/src/rules/avoid_as.dart';
 import 'package:path/path.dart';
 import 'package:plugin/manager.dart';
 import 'package:plugin/plugin.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import 'mock_sdk.dart';
 import 'mocks.dart';
 import 'utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(AbstractContextManagerTest);
-  defineReflectiveTests(ContextManagerWithNewOptionsTest);
-  defineReflectiveTests(ContextManagerWithOldOptionsTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(AbstractContextManagerTest);
+    defineReflectiveTests(ContextManagerWithNewOptionsTest);
+    defineReflectiveTests(ContextManagerWithOldOptionsTest);
+  });
 }
 
 @reflectiveTest
 class AbstractContextManagerTest extends ContextManagerTest {
   void test_contextsInAnalysisRoot_nestedContext() {
     String subProjPath = posix.join(projPath, 'subproj');
     Folder subProjFolder = resourceProvider.newFolder(subProjPath);
     resourceProvider.newFile(
         posix.join(subProjPath, 'pubspec.yaml'), 'contents');
     String subProjFilePath = posix.join(subProjPath, 'file.dart');
@@ skipping 2704 matching lines @@
 class TestUriResolver extends UriResolver {
   Map<Uri, Source> uriMap;
 
   TestUriResolver(this.uriMap);
 
   @override
   Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     return uriMap[uri];
   }
 }