Move diagnostics to `diagnostics` domain (#24931).

pkg/analysis_server/test/domain_experimental_test.dart

-// Copyright (c) 2015, 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.domain.experimental;
-
-import 'package:analysis_server/plugin/protocol/protocol.dart';
-import 'package:analysis_server/src/analysis_server.dart';
-import 'package:analysis_server/src/domain_experimental.dart';
-import 'package:analysis_server/src/plugin/server_plugin.dart';
-import 'package:analyzer/file_system/memory_file_system.dart';
-import 'package:analyzer/instrumentation/instrumentation.dart';
-import 'package:plugin/manager.dart';
-import 'package:unittest/unittest.dart';
-
-import 'mock_sdk.dart';
-import 'mocks.dart';
-import 'utils.dart';
-
-main() {
-  AnalysisServer server;
-  ExperimentalDomainHandler handler;
-  MemoryResourceProvider resourceProvider;
-
-  initializeTestEnvironment();
-
-  setUp(() {
-    var serverChannel = new MockServerChannel();
-    resourceProvider = new MemoryResourceProvider();
-    ExtensionManager manager = new ExtensionManager();
-    ServerPlugin serverPlugin = new ServerPlugin();
-    manager.processPlugins([serverPlugin]);
-    server = new AnalysisServer(
-        serverChannel,
-        resourceProvider,
-        new MockPackageMapProvider(),
-        null,
-        serverPlugin,
-        new AnalysisServerOptions(),
-        new MockSdk(),
-        InstrumentationService.NULL_SERVICE);
-    handler = new ExperimentalDomainHandler(server);
-  });
-
-  group('ExperimentalDomainHandler', () {
-    test('getDiagnostics', () async {
-      String file = '/project/bin/test.dart';
-      resourceProvider.newFile('/project/pubspec.yaml', 'name: project');
-      resourceProvider.newFile(file, 'main() {}');
-
-      server.setAnalysisRoots('0', ['/project/'], [], {});
-
-      await server.onAnalysisComplete;
-
-      var request = new ExperimentalGetDiagnosticsParams().toRequest('0');
-      var response = handler.handleRequest(request);
-
-      int fileCount = MockSdk.LIBRARIES.length + 1 /* test.dart */;
-
-      var json = response.toJson()[Response.RESULT];
-      expect(json['contexts'], hasLength(1));
-      var context = json['contexts'][0];
-      expect(context['name'], '/project');
-      expect(context['explicitFileCount'], fileCount);
-      expect(context['implicitFileCount'], 0);
-      expect(context['workItemQueueLength'], isNotNull);
-    });
-
-    test('getDiagnostics - (no root)', () async {
-      var request = new ExperimentalGetDiagnosticsParams().toRequest('0');
-      var response = handler.handleRequest(request);
-      var json = response.toJson()[Response.RESULT];
-      expect(json['contexts'], hasLength(0));
-    });
-  });
-}