Use StreamChannel.

lib/src/client.dart

Index: lib/src/client.dart
diff --git a/lib/src/client.dart b/lib/src/client.dart
index e75e7f38c0041f64bab8a4a90f29416c2a914ac3..5df21e438c0e8423b3ef0101bd77310f285eb379 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -5,9 +5,10 @@
 import 'dart:async';
 
 import 'package:stack_trace/stack_trace.dart';
+import 'package:stream_channel/stream_channel.dart';
 
+import 'channel_manager.dart';
 import 'exception.dart';
-import 'two_way_stream.dart';
 import 'utils.dart';
 
 /// A JSON-RPC 2.0 client.
@@ -16,7 +17,7 @@ import 'utils.dart';
 /// those method calls. Methods can be called with [sendRequest], or with
 /// [sendNotification] if no response is expected.
 class Client {
-  final TwoWayStream _streams;
+  final ChannelManager _manager;
 
   /// The next request id.
   var _id = 0;
@@ -29,55 +30,53 @@ class Client {
   /// The map of request ids to pending requests.
   final _pendingRequests = new Map<int, _Request>();
 
-  /// Returns a [Future] that completes when the connection is closed.
+  /// Returns a [Future] that completes when the underlying connection is
+  /// closed.
   ///
-  /// This is the same future that's returned by [listen].
-  Future get done => _streams.done;
+  /// This is the same future that's returned by [listen] and [close]. It may
+  /// complete before [close] is called if the remote endpoint closes the
+  /// connection.
+  Future get done => _manager.done;
 
-  /// Whether the connection is closed.
-  bool get isClosed => _streams.isClosed;
-
-  /// Creates a [Client] that writes requests to [requests] and reads responses
-  /// from [responses].
+  /// Whether the underlying connection is closed.
   ///
-  /// If [responses] is a [StreamSink] as well as a [Stream] (for example, a
-  /// `WebSocket`), [requests] may be omitted.
+  /// Note that this will be `true` before [close] is called if the remote
+  /// endpoint closes the connection.
+  bool get isClosed => _manager.isClosed;
+
+  /// Creates a [Client] that communicates over [channel].
   ///
   /// Note that the client won't begin listening to [responses] until
   /// [Client.listen] is called.
-  Client(Stream<String> responses, [StreamSink<String> requests])
-      : _streams = new TwoWayStream(
-            "Client", responses, "responses", requests, "requests");
+  Client(StreamChannel<String> channel)
+      : this.withoutJson(channel
+            .transform(jsonDocument)
+            .transformStream(ignoreFormatExceptions));
 
-  /// Creates a [Client] that writes decoded responses to [responses] and reads
-  /// decoded requests from [requests].
+  /// Creates a [Client] that communicates using decoded messages over
+  /// [channel].
   ///
   /// Unlike [new Client], this doesn't read or write JSON strings. Instead, it
   /// reads and writes decoded maps or lists.
   ///
-  /// If [responses] is a [StreamSink] as well as a [Stream], [requests] may be
-  /// omitted.
-  ///
   /// Note that the client won't begin listening to [responses] until
   /// [Client.listen] is called.
-  Client.withoutJson(Stream responses, [StreamSink requests])
-      : _streams = new TwoWayStream.withoutJson(
-            "Client", responses, "responses", requests, "requests");
+  Client.withoutJson(StreamChannel channel)
+      : _manager = new ChannelManager("Client", channel);
 
   /// Starts listening to the underlying stream.
   ///
-  /// Returns a [Future] that will complete when the stream is closed or when it
-  /// has an error.
+  /// Returns a [Future] that will complete when the connection is closed or
+  /// when it has an error. This is the same as [done].
   ///
   /// [listen] may only be called once.
-  Future listen() => _streams.listen(_handleResponse);
+  Future listen() => _manager.listen(_handleResponse);
 
-  /// Closes the server's request sink and response subscription.
+  /// Closes the underlying connection.
   ///
   /// Returns a [Future] that completes when all resources have been released.
-  ///
-  /// A client can't be closed before [listen] has been called.
-  Future close() => _streams.close();
+  /// This is the same as [done].
+  Future close() => _manager.close();
 
   /// Sends a JSON-RPC 2 request to invoke the given [method].
   ///
@@ -132,7 +131,7 @@ class Client {
     if (_batch != null) {
       _batch.add(message);
     } else {
-      _streams.add(message);
+      _manager.add(message);
     }
   }
 
@@ -153,7 +152,7 @@ class Client {
 
     _batch = [];
     return tryFinally(callback, () {
-      _streams.add(_batch);
+      _manager.add(_batch);
       _batch = null;
     });
   }