Add integration tests for the execution domain.

pkg/analyzer_plugin/test/integration/support/integration_tests.dart

 // 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 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer_plugin/protocol/protocol_generated.dart';
@@ skipping 243 matching lines @@
    */
   String writeFile(String pathname, String contents) {
     new Directory(dirname(pathname)).createSync(recursive: true);
     File file = new File(pathname);
     file.writeAsStringSync(contents);
     return file.resolveSymbolicLinksSync();
   }
 }
 
 /**
+ * An error result from a server call.

[Brian Wilkerson, 2017/02/12 18:47:09]

I was going to suggest changing "server" to "plugin" (and rename the class to
"PluginErrorMessage"), but now that I look at the code more closely, I'm not
sure that's appropriate. My guess at this point (I can look into this more if
you want me to) is that I copied too much when copying this file and that a
large portion of this file is probably unused. (Sure would be nice to have a
global dead-code analysis tool.)

nit: "call" --> "request"

[devoncarew, 2017/02/12 19:22:47]

Updated the dartdoc (call -> request).

I'm happy to take a quick look through this file (after this CL lands).

+ */
+class ServerErrorMessage {
+  final Map message;
+
+  ServerErrorMessage(this.message);
+
+  dynamic get error => message['error'];
+}
+
+/**
  * Wrapper class for Matcher which doesn't create the underlying Matcher object
  * until it is needed.  This is necessary in order to create matchers that can
  * refer to themselves (so that recursive data structures can be represented).
  */
 class LazyMatcher implements Matcher {
   /**
    * Callback that will be used to create the matcher the first time it is
    * needed.
    */
   final MatcherCreator _creator;
@@ skipping 277 matching lines @@
       if (messageAsMap.containsKey('id')) {
         outOfTestExpect(messageAsMap['id'], isString);
         String id = message['id'];
         Completer completer = _pendingCommands[id];
         if (completer == null) {
           fail('Unexpected response from server: id=$id');
         } else {
           _pendingCommands.remove(id);
         }
         if (messageAsMap.containsKey('error')) {
-          // TODO(paulberry): propagate the error info to the completer.
-          completer.completeError(new UnimplementedError(
-              'Server responded with an error: ${JSON.encode(message)}'));
+          completer.completeError(new ServerErrorMessage(messageAsMap));
         } else {
           completer.complete(messageAsMap['result']);
         }
         // Check that the message is well-formed.  We do this after calling
         // completer.complete() or completer.completeError() so that we don't
         // stall the test in the event of an error.
         outOfTestExpect(message, isResponse);
       } else {
         // Message is a notification.  It should have an event and possibly
         // params.
@@ skipping 367 matching lines @@
   void populateMismatches(item, List<MismatchDescriber> mismatches);
 
   /**
    * Create a [MismatchDescriber] describing a mismatch with a simple string.
    */
   MismatchDescriber simpleDescription(String description) =>
       (Description mismatchDescription) {
         mismatchDescription.add(description);
       };
 }