Make pub strong-mode clean.

lib/src/barback/web_socket_api.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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
 import 'package:web_socket_channel/web_socket_channel.dart';
@@ skipping 10 matching lines @@
 /// This is a [JSON-RPC 2.0](http://www.jsonrpc.org/specification) server. Its
 /// methods are described in the method-level documentation below.
 class WebSocketApi {
   final AssetEnvironment _environment;
   final json_rpc.Server _server;
 
   /// Whether the application should exit when this connection closes.
   bool _exitOnClose = false;
 
   WebSocketApi(WebSocketChannel socket, this._environment)
-      : _server = new json_rpc.Server(socket) {
+      : _server = new json_rpc.Server(socket.cast()) {
     _server.registerMethod("urlToAssetId", _urlToAssetId);
     _server.registerMethod("pathToUrls", _pathToUrls);
     _server.registerMethod("serveDirectory", _serveDirectory);
     _server.registerMethod("unserveDirectory", _unserveDirectory);
 
     /// Tells the server to exit as soon as this WebSocket connection is closed.
     ///
     /// This takes no arguments and returns no results. It can safely be called
     /// as a JSON-RPC notification.
     _server.registerMethod("exitOnClose", () {
@@ skipping 67 matching lines @@
     return _environment.getAssetIdForUrl(url).then((id) {
       if (id == null) {
         throw new json_rpc.RpcException(_Error.NOT_SERVED,
             '"${url.host}:${url.port}" is not being served by pub.');
       }
 
       // TODO(rnystrom): When this is hooked up to actually talk to barback to
       // see if assets exist, consider supporting implicit index.html at that
       // point.
 
-      var result = {"package": id.package, "path": id.path};
+      var result = <String, Object>{"package": id.package, "path": id.path};
 
       // Map the line.
       // TODO(rnystrom): Right now, source maps are not supported and it just
       // passes through the original line. This lets the editor start using
       // this API before we've fully implemented it. See #12339 and #16061.
       if (line != null) result["line"] = line;
 
       return result;
     });
   }
@@ skipping 51 matching lines @@
   Future<Map> _pathToUrls(json_rpc.Parameters params) {
     var assetPath = params["path"].asString;
     var line = params["line"].asIntOr(null);
 
     return _environment.getUrlsForAssetPath(assetPath).then((urls) {
       if (urls.isEmpty) {
         throw new json_rpc.RpcException(_Error.NOT_SERVED,
             'Asset path "$assetPath" is not currently being served.');
       }
 
-      var result = {"urls": urls.map((url) => url.toString()).toList()};
+      var result = <String, Object>{
+        "urls": urls.map((url) => url.toString()).toList()
+      };
 
       // Map the line.
       // TODO(rnystrom): Right now, source maps are not supported and it just
       // passes through the original line. This lets the editor start using
       // this API before we've fully implemented it. See #12339 and #16061.
       if (line != null) result["line"] = line;
 
       return result;
     });
   }
@@ skipping 96 matching lines @@
 }
 
 /// The pub-specific JSON RPC error codes.
 class _Error {
   /// The specified directory is not being served.
   static const NOT_SERVED = 1;
 
   /// The specified directory overlaps one or more ones already being served.
   static const OVERLAPPING = 2;
 }