Add a diagnostic.getServerPort analysis server request.

pkg/analysis_server/lib/src/domain_diagnostic.dart

Index: pkg/analysis_server/lib/src/domain_diagnostic.dart
diff --git a/pkg/analysis_server/lib/src/domain_diagnostic.dart b/pkg/analysis_server/lib/src/domain_diagnostic.dart
index d91aacf886083dab04a6962b2898a0b34d57a185..41056b03ec58157b60f399620fbc88f952eb9d80 100644
--- a/pkg/analysis_server/lib/src/domain_diagnostic.dart
+++ b/pkg/analysis_server/lib/src/domain_diagnostic.dart
@@ -28,7 +28,8 @@ int _workItemCount(AnalysisContextImpl context) {
 /// [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;
@@ -101,12 +102,29 @@ class DiagnosticDomainHandler implements RequestHandler {
   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;
+  }
 }