Add tests for recently added mixins and improve plugin tests

pkg/analyzer_plugin/test/plugin/mocks.dart

Index: pkg/analyzer_plugin/test/plugin/mocks.dart
diff --git a/pkg/analyzer_plugin/test/plugin/mocks.dart b/pkg/analyzer_plugin/test/plugin/mocks.dart
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+++ b/pkg/analyzer_plugin/test/plugin/mocks.dart
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+// Copyright (c) 2017, 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.
+
+import 'dart:async';
+
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/src/dart/analysis/driver.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer_plugin/channel/channel.dart';
+import 'package:analyzer_plugin/plugin/plugin.dart';
+import 'package:analyzer_plugin/protocol/protocol.dart';
+import 'package:analyzer_plugin/protocol/protocol_generated.dart';
+import 'package:analyzer_plugin/src/protocol/protocol_internal.dart';
+import 'package:front_end/src/base/timestamped_data.dart';
+import 'package:test/test.dart';
+
+class MockAnalysisDriver extends AnalysisDriverGeneric {
+  /**
+   * The files that have been added to this driver.
+   */
+  List<String> addedFiles = <String>[];
+
+  @override
+  bool get hasFilesToAnalyze => false;
+
+  @override
+  set priorityFiles(List<String> priorityPaths) {}
+
+  @override
+  AnalysisDriverPriority get workPriority => AnalysisDriverPriority.nothing;
+
+  @override
+  void addFile(String path) {
+    addedFiles.add(path);
+  }
+
+  @override
+  void dispose() {}
+
+  @override
+  Future<Null> performWork() => new Future.value(null);
+}
+
+class MockChannel implements PluginCommunicationChannel {
+  bool _closed = false;
+
+  void Function(Request) _onRequest;
+  Function _onError;
+  void Function() _onDone;
+
+  int idCounter = 0;
+
+  Map<String, Completer<Response>> completers = <String, Completer<Response>>{};
+
+  @override
+  void close() {
+    _closed = true;
+  }
+
+  @override
+  void listen(void onRequest(Request request),
+      {Function onError, void onDone()}) {
+    _onRequest = onRequest;
+    _onError = onError;
+    _onDone = onDone;
+  }
+
+  void sendDone() {
+    _onDone();
+  }
+
+  void sendError(Object exception, StackTrace stackTrace) {
+    _onError(exception, stackTrace);
+  }
+
+  @override
+  void sendNotification(Notification notification) {
+    if (_closed) {
+      throw new StateError('Sent a notification to a closed channel');
+    }
+    fail('Unexpected invocation of sendNotification');
+  }
+
+  Future<Response> sendRequest(RequestParams params) {
+    String id = (idCounter++).toString();
+    Request request = params.toRequest(id);
+    Completer<Response> completer = new Completer<Response>();
+    completers[request.id] = completer;
+    _onRequest(request);
+    return completer.future;
+  }
+
+  @override
+  void sendResponse(Response response) {
+    if (_closed) {
+      throw new StateError('Sent a response to a closed channel');
+    }
+    Completer<Response> completer = completers.remove(response.id);
+    completer.complete(response);
+  }
+}
+
+/**
+ * A concrete implementation of a server plugin that is suitable for testing.
+ */
+class MockServerPlugin extends ServerPlugin {
+  MockServerPlugin(ResourceProvider resourceProvider) : super(resourceProvider);
+
+  @override
+  List<String> get fileGlobsToAnalyze => <String>['*.dart'];
+
+  @override
+  String get name => 'Test Plugin';
+
+  @override
+  String get version => '0.1.0';
+
+  @override
+  AnalysisDriverGeneric createAnalysisDriver(ContextRoot contextRoot) {
+    return new MockAnalysisDriver();
+  }
+
+  @override
+  void sendNotificationsForSubscriptions(
+      Map<String, List<AnalysisService>> subscriptions) {}
+}
+
+class MockSource implements Source {
+  @override
+  TimestampedData<String> get contents => null;
+
+  @override
+  String get encoding => null;
+
+  @override
+  String get fullName => '/pkg/lib/test.dart';
+
+  @override
+  bool get isInSystemLibrary => false;
+
+  @override
+  Source get librarySource => this;
+
+  @override
+  int get modificationStamp => 0;
+
+  @override
+  String get shortName => 'test.dart';
+
+  @override
+  Source get source => this;
+
+  @override
+  Uri get uri => Uri.parse('package:test/test.dart');
+
+  @override
+  UriKind get uriKind => UriKind.PACKAGE_URI;
+
+  @override
+  bool exists() => true;
+}