Fix some WebSocket strong-mode errors and warnings.

sdk/lib/io/websocket_impl.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 const String _webSocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 const String _clientNoContextTakeover = "client_no_context_takeover";
 const String _serverNoContextTakeover = "server_no_context_takeover";
 const String _clientMaxWindowBits = "client_max_window_bits";
@@ skipping 40 matching lines @@
 /**
  * The web socket protocol transformer handles the protocol byte stream
  * which is supplied through the [:handleData:]. As the protocol is processed,
  * it'll output frame data as either a List<int> or String.
  *
  * Important information about usage: Be sure you use cancelOnError, so the
  * socket will be closed when the processor encounter an error. Not using it
  * will lead to undefined behaviour.
  */
 // TODO(ajohnsen): make this transformer reusable?
-class _WebSocketProtocolTransformer implements StreamTransformer, EventSink {
+class _WebSocketProtocolTransformer
+    implements StreamTransformer<List<int>, dynamic>, EventSink<List<int>> {
   static const int START = 0;
   static const int LEN_FIRST = 1;
   static const int LEN_REST = 2;
   static const int MASK = 3;
   static const int PAYLOAD = 4;
   static const int CLOSED = 5;
   static const int FAILURE = 6;
   static const int FIN = 0x80;
   static const int RSV1 = 0x40;
   static const int RSV2 = 0x20;
@@ skipping 35 matching lines @@
 
   void addError(Object error, [StackTrace stackTrace]) {
     _eventSink.addError(error, stackTrace);
   }
 
   void close() { _eventSink.close(); }
 
   /**
    * Process data received from the underlying communication channel.
    */
-  void add(Uint8List buffer) {
+  void add(List<int> bytes) {
+    var buffer = bytes is Uint8List ? bytes : new Uint8List.fromList(bytes);
     int index = 0;
     int lastIndex = buffer.length;
     if (_state == CLOSED) {
       throw new WebSocketException("Data on closed connection");
     }
     if (_state == FAILURE) {
       throw new WebSocketException("Data on failed connection");
     }
     while ((index < lastIndex) && _state != CLOSED && _state != FAILURE) {
       int byte = buffer[index];
@@ skipping 491 matching lines @@
 
     if (result.length > 4) {
       result = result.sublist(0, result.length - 4);
     }
 
     return result;
   }
 }
 
 // TODO(ajohnsen): Make this transformer reusable.
-class _WebSocketOutgoingTransformer implements StreamTransformer, EventSink {
+class _WebSocketOutgoingTransformer
+    implements StreamTransformer<dynamic, List<int>>, EventSink {
   final _WebSocketImpl webSocket;
-  EventSink _eventSink;
+  EventSink<List<int>> _eventSink;
 
   _WebSocketPerMessageDeflate _deflateHelper;
 
   _WebSocketOutgoingTransformer(this.webSocket) {
     _deflateHelper = webSocket._deflate;
   }
 
-  Stream bind(Stream stream) {
-    return new Stream.eventTransformed(stream, (EventSink eventSink) {
+  Stream<List<int>> bind(Stream stream) {
+    return new Stream.eventTransformed(stream, (eventSink) {
       if (_eventSink != null) {
         throw new StateError("WebSocket transformer already used");
       }
       _eventSink = eventSink;
       return this;
     });
   }
 
   void add(message) {
     if (message is _WebSocketPong) {
       addFrame(_WebSocketOpcode.PONG, message.payload);
       return;
     }
     if (message is _WebSocketPing) {
       addFrame(_WebSocketOpcode.PING, message.payload);
       return;
     }
     List<int> data;
     int opcode;
     if (message != null) {
       if (message is String) {
         opcode = _WebSocketOpcode.TEXT;
         data = UTF8.encode(message);
       } else {
-        if (message is! List<int>) {
+        if (message is List<int>) {
+          data = message;
+          opcode = _WebSocketOpcode.BINARY;
+        } else {
           throw new ArgumentError(message);
         }
-        opcode = _WebSocketOpcode.BINARY;
-        data = message;
       }
 
       if (_deflateHelper != null) {
         data = _deflateHelper.processOutgoingMessage(data);
       }
     } else {
       opcode = _WebSocketOpcode.TEXT;
     }
     addFrame(opcode, data);
   }
@@ skipping 21 matching lines @@
   void addFrame(int opcode, List<int> data) => createFrame(
           opcode,
           data,
           webSocket._serverSide,
           _deflateHelper != null &&
               (opcode == _WebSocketOpcode.TEXT ||
                   opcode == _WebSocketOpcode.BINARY)).forEach((e) {
         _eventSink.add(e);
       });
 
-  static Iterable createFrame(
+  static Iterable<List<int>> createFrame(
       int opcode, List<int> data, bool serverSide, bool compressed) {
     bool mask = !serverSide; // Masking not implemented for server.
     int dataLength = data == null ? 0 : data.length;
     // Determine the header size.
     int headerSize = (mask) ? 6 : 2;
     if (dataLength > 65535) {
       headerSize += 8;
     } else if (dataLength > 125) {
       headerSize += 2;
     }
@@ skipping 489 matching lines @@
     _writeClosed = true;
     _consumer.closeSocket();
     _webSockets.remove(_serviceId);
   }
 
   String get _serviceTypePath => 'io/websockets';
   String get _serviceTypeName => 'WebSocket';
 
   Map _toJSON(bool ref) {
     var name = '${_socket.address.host}:${_socket.port}';
-    var r = {
+    var r = <String, dynamic>{
       'id': _servicePath,
       'type': _serviceType(ref),
       'name': name,
       'user_name': name,
     };
     if (ref) {
       return r;
     }
     try {
       r['socket'] = _socket._toJSON(true);
@@ skipping 12 matching lines @@
     return code != null &&
         (code < WebSocketStatus.NORMAL_CLOSURE ||
             code == WebSocketStatus.RESERVED_1004 ||
             code == WebSocketStatus.NO_STATUS_RECEIVED ||
             code == WebSocketStatus.ABNORMAL_CLOSURE ||
             (code > WebSocketStatus.INTERNAL_SERVER_ERROR &&
                 code < WebSocketStatus.RESERVED_1015) ||
             (code >= WebSocketStatus.RESERVED_1015 && code < 3000));
   }
 }