Add a diagnostic.getServerPort analysis server request.

pkg/analysis_server/lib/src/domain_diagnostic.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 analysis_server.src.domain_diagnostic;
 
 import 'dart:collection';
 import 'dart:core';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
@@ skipping 10 matching lines @@
 int _workItemCount(AnalysisContextImpl context) {
   AnalysisDriver driver = context.driver;
   List<WorkItem> items = driver.currentWorkOrder?.workItems;
   return items?.length ?? 0;
 }
 
 /// Instances of the class [DiagnosticDomainHandler] implement a
 /// [RequestHandler] that handles requests in the `diagnostic` domain.
 class DiagnosticDomainHandler implements RequestHandler {
   /// The name of the request used to get diagnostic information.
-  static const String DIAGNOSTICS = 'diagnostic.getDiagnostics';
+  static const String GET_DIAGNOSTICS = 'diagnostic.getDiagnostics';
+  static const String GET_SERVER_PORT = 'diagnostic.getServerPort';

[Brian Wilkerson, 2017/02/18 21:41:03]

The rest of the constants like this are in the file
"pkg/analysis_server/lib/src/constants.dart". It would be nice to keep them all
together and use a consistent naming scheme.

[devoncarew, 2017/02/19 02:43:05]

Good to know; moved these into constants.dart and updated their names.

 
   /// The analysis server that is using this handler to process requests.
   final AnalysisServer server;
 
   /// Initialize a newly created handler to handle requests for the given
   /// [server].
   DiagnosticDomainHandler(this.server);
 
   /// Answer the `diagnostic.diagnostics` request.
   Response computeDiagnostics(Request request) {
@@ skipping 52 matching lines @@
     int explicitFileCount = driver.addedFiles.length;
     int knownFileCount = driver.knownFiles.length;
     return new ContextData(driver.name, explicitFileCount,
         knownFileCount - explicitFileCount, driver.numberOfFilesToAnalyze, []);
   }
 
   @override
   Response handleRequest(Request request) {
     try {
       String requestName = request.method;
-      if (requestName == DIAGNOSTICS) {
+      if (requestName == GET_DIAGNOSTICS) {
         return computeDiagnostics(request);
+      } else if (requestName == GET_SERVER_PORT) {
+        return getServerPort(request);
       }
     } on RequestFailure catch (exception) {
       return exception.response;
     }
     return null;
   }
+
+  /// Answer the `diagnostic.getServerPort` request.
+  Response getServerPort(Request request) {

[Brian Wilkerson, 2017/02/18 21:41:03]

Convert this to use an async body? I find it to be much more readable.

[devoncarew, 2017/02/19 02:43:04]

Sure, done.

As an aside, I'm wondering if the `Response handleRequest(Request request)`
handlers for the domains should all be async (return Future<Response>)? Many of
the requests seems async in nature.

+    // Open a port (or return the existing one).
+    server.diagnosticServer.getServerPort().then((int port) {
+      Response response =
+          new DiagnosticGetServerPortResult(port).toResponse(request.id);
+      server.sendResponse(response);
+    }).catchError((error) {
+      server.sendResponse(new Response.errorHandlingRequest(request, error));
+    });
+
+    // delay response
+    return Response.DELAYED_RESPONSE;
+  }
 }