module HTTPX::Plugins::Upgrade::InstanceMethods

   # File lib/httpx/plugins/upgrade.rb
31 def fetch_response(request, selector, options)
32   response = super
33 
34   if response
35     return response unless response.is_a?(Response)
36 
37     return response unless response.headers.key?("upgrade")
38 
39     upgrade_protocol = response.headers["upgrade"].split(/ *, */).first
40 
41     return response unless upgrade_protocol && options.upgrade_handlers.key?(upgrade_protocol)
42 
43     protocol_handler = options.upgrade_handlers[upgrade_protocol]
44 
45     return response unless protocol_handler
46 
47     log { "upgrading to #{upgrade_protocol}..." }
48     connection = find_connection(request.uri, selector, options)
49 
50     # do not upgrade already upgraded connections
51     return if connection.upgrade_protocol == upgrade_protocol
52 
53     protocol_handler.call(connection, request, response)
54 
55     # keep in the loop if the server is switching, unless
56     # the connection has been hijacked, in which case you want
57     # to terminante immediately
58     return if response.status == 101 && !connection.hijacked
59   end
60 
61   response
62 end