Revert "Make package strong, also add analysis options file"

This reverts commit b38b9c5.

Author: keertip

analysis_options.yaml

@@ -5,6 +5,7 @@
 import 'dart:convert';
 
 import 'package:shelf/shelf.dart';
+import 'package:stream_channel/stream_channel.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
 
 /// A class that exposes a handler for upgrading WebSocket requests.
@@ -26,8 +27,8 @@ class WebSocketHandler {
 
     var connection = request.headers['Connection'];
     if (connection == null) return _notFound();
-    var tokens =
-        connection.toLowerCase().split(',').map((token) => token.trim());
+    var tokens = connection.toLowerCase().split(',')
+        .map((token) => token.trim());
     if (!tokens.contains('upgrade')) return _notFound();
 
     var upgrade = request.headers['Upgrade'];
@@ -58,18 +59,18 @@ class WebSocketHandler {
     // unexpected origins, we ensure that malicious JavaScript is unable to fake
     // a WebSocket handshake.
     var origin = request.headers['Origin'];
-    if (origin != null &&
-        _allowedOrigins != null &&
+    if (origin != null && _allowedOrigins != null &&
         !_allowedOrigins.contains(origin.toLowerCase())) {
       return _forbidden('invalid origin "$origin".');
     }
 
     var protocol = _chooseProtocol(request);
     request.hijack((untypedChannel) {
-      var channel = untypedChannel.cast<List<int>>();
+      var channel = (untypedChannel as StreamChannel).cast<List<int>>();
 
       var sink = UTF8.encoder.startChunkedConversion(channel.sink);
-      sink.add("HTTP/1.1 101 Switching Protocols\r\n"
+      sink.add(
+          "HTTP/1.1 101 Switching Protocols\r\n"
           "Upgrade: websocket\r\n"
           "Connection: Upgrade\r\n"
           "Sec-WebSocket-Accept: ${WebSocketChannel.signKey(key)}\r\n");
@@ -99,20 +100,20 @@ class WebSocketHandler {
   }
 
   /// Returns a 404 Not Found response.
-  Response _notFound() => _htmlResponse(
-      404, "404 Not Found", "Only WebSocket connections are supported.");
+  Response _notFound() => _htmlResponse(404, "404 Not Found",
+      "Only WebSocket connections are supported.");
 
   /// Returns a 400 Bad Request response.
   ///
   /// [message] will be HTML-escaped before being included in the response body.
-  Response _badRequest(String message) => _htmlResponse(
-      400, "400 Bad Request", "Invalid WebSocket upgrade request: $message");
+  Response _badRequest(String message) => _htmlResponse(400, "400 Bad Request",
+      "Invalid WebSocket upgrade request: $message");
 
   /// Returns a 403 Forbidden response.
   ///
   /// [message] will be HTML-escaped before being included in the response body.
-  Response _forbidden(String message) => _htmlResponse(
-      403, "403 Forbidden", "WebSocket upgrade refused: $message");
+  Response _forbidden(String message) => _htmlResponse(403, "403 Forbidden",
+      "WebSocket upgrade refused: $message");
 
   /// Creates an HTTP response with the given [statusCode] and an HTML body with
   /// [title] and [message].