Improve websocket match logic. Fixes #401

spec/websocket_handler_spec.cr

@@ -47,4 +47,20 @@ describe "Kemal::WebSocketHandler" do
     io_with_context = create_ws_request_and_return_io(handler, request)
     io_with_context.to_s.should eq("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-Websocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n\r\n")
   end
+
+  it "matches correct verb" do
+    handler = Kemal::WebSocketHandler::INSTANCE
+    handler.next = Kemal::RouteHandler::INSTANCE
+    ws "/" { }
+    get "/" { "get" }
+    request = HTTP::Request.new("GET", "/")
+    io = IO::Memory.new
+    response = HTTP::Server::Response.new(io)
+    context = HTTP::Server::Context.new(request, response)
+    handler.call(context)
+    response.close
+    io.rewind
+    client_response = HTTP::Client::Response.from_io(io, decompress: false)
+    client_response.body.should eq("get")
+  end
 end

src/kemal/websocket_handler.cr

@@ -11,7 +11,7 @@ module Kemal
     end
 
     def call(context : HTTP::Server::Context)
-      return call_next(context) unless context.ws_route_defined?
+      return call_next(context) unless context.ws_route_defined? && websocket_upgrade_request?(context)
       context.request.url_params ||= context.ws_route_lookup.params
       content = context.websocket.call(context)
       context.response.print(content)
@@ -34,5 +34,12 @@ module Kemal
     private def radix_path(method, path)
       "/#{method.downcase}#{path}"
     end
+
+    private def websocket_upgrade_request?(context)
+      return false unless upgrade = context.request.headers["Upgrade"]?
+      return false unless upgrade.compare("websocket", case_insensitive: true) == 0
+
+      context.request.headers.includes_word?("Connection", "Upgrade")
+    end
   end
 end