implement ByteStreamClientChannel close

pkg/analysis_server/lib/src/channel.dart

 // Copyright (c) 2014, 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 channel;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 184 matching lines @@
         .transform(new ResponseConverter())
         .asBroadcastStream();
     notificationStream = jsonStream
         .where((json) => json[Notification.EVENT] != null)
         .transform(new NotificationConverter())
         .asBroadcastStream();
   }
 
   @override
   Future close() {
-    // TODO: implement close
+    return output.close();
   }
 
   @override
   Future<Response> sendRequest(Request request) {
     String id = request.id;
     output.writeln(JSON.encode(request.toJson()));
     return responseStream.firstWhere((Response response) => response.id == id);
   }
 }
 
@@ skipping 56 matching lines @@
     onRequest(request);
   }
 }
 
 /**
  * Instances of the class [JsonStreamDecoder] convert JSON strings to JSON
  * maps.
  */
 class JsonStreamDecoder extends Converter<String, Map> {
   @override
-  Map convert(String text) => JSON.decode(text);
+  Map convert(String text) {
+    if (text == null || text.isEmpty || text[0] != '{') {

[Paul Berry, 2014/05/16 18:01:27]

Is this an intentional part of the CL?  What's the purpose of the change?

At first blush it seems to me that we're better off just passing the text
through to JSON.decode() and letting it throw an exception if it's bad. 
Returning null for malformed input carries the risk of masking bugs.

[danrubel, 2014/05/19 17:32:25]

This is to allow stack traces from the analysis server flow through to the
client, but maybe there is a better way to do this. I'll roll this back for now.

+      return null;
+    }
+    return JSON.decode(text);
+  }
 
   @override
   ChunkedConversionSink startChunkedConversion(Sink sink) =>
       new ChannelChunkSink<String, Map>(this, sink);
 }
 
 /**
  * Instances of the class [ResponseConverter] convert JSON maps to [Response]s.
  */
 class ResponseConverter extends Converter<Map, Response> {
@@ skipping 53 matching lines @@
       }
     }
   }
 
   @override
   void close() {
     closed = true;
     sink.close();
   }
 }