Unexpected exception on redis disconnect Redis - NoMethodError(undefined method `destroy' for nil:NilClass)

从 ruby/hyper-operation/transport/connection_adapter/redis.rb 第 66 行开始，然后阅读经过 connection.rb 和 action_cable.rb 的 disconnect 调用链。跟踪 Redis 断开连接路径为何会在 nil 上调用 destroy；完成标准是断开 channel 不再引发报告中的 NoMethodError。

I switched recently to the new Redis message functionality and I get the following exception in production.log

I, [2021-02-25T14:13:45.826641 #1289]  INFO -- : Finished "/cable/" [WebSocket] for 127.0.0.1 at 2021-02-25 14:13:45 +0200
I, [2021-02-25T14:13:45.830986 #1289]  INFO -- : Hyperstack::ActionCableChannel stopped streaming from hyperstack-AnnouncementCategory
I, [2021-02-25T14:13:45.926758 #1266]  INFO -- : Finished "/cable/" [WebSocket] for 127.0.0.1 at 2021-02-25 14:13:45 +0200
I, [2021-02-25T14:13:45.933053 #1266]  INFO -- : Hyperstack::ActionCableChannel stopped streaming from hyperstack-AnnouncementCategory
I, [2021-02-25T14:13:46.010028 #1266]  INFO -- : Hyperstack::ActionCableChannel stopped streaming from hyperstack-Epos::Applicant-423783
I, [2021-02-25T14:13:46.028519 #1266]  INFO -- : Hyperstack::ActionCableChannel stopped streaming from hyperstack-Hyperstack::Session-e570d5777171d6ae432a94fef3735d11
E, [2021-02-25T14:13:46.159163 #1289] ERROR -- : There was an exception - NoMethodError(undefined method `destroy' for nil:NilClass)
E, [2021-02-25T14:13:46.162694 #1289] ERROR -- : /home/app/shared/bundle/ruby/2.7.0/bundler/gems/hyperstack-f07d016b626a/ruby/hyper-operation/lib/hyper-operation/transport/connection_adapter/redis.rb:66:in `disconnect'
/home/app/shared/bundle/ruby/2.7.0/bundler/gems/hyperstack-f07d016b626a/ruby/hyper-operation/lib/hyper-operation/transport/connection.rb:68:in `disconnect'
/home/app/shared/bundle/ruby/2.7.0/bundler/gems/hyperstack-f07d016b626a/ruby/hyper-operation/lib/hyper-operation/transport/action_cable.rb:36:in `unsubscribed'

I had the same problem when using the db message store and back then i had to patch hyperstack.rb initializer with the following patch from @catmando :

module Hyperstack
  class Connection < ActiveRecord::Base
    def self.disconnect(channel)
      puts "\ndisconnecting from #{channel}\n" if Rails.env.development?
      c = find_by(channel: channel, session: nil)
      if c
        c.destroy
      else
        puts "\n********************** WARNING #{channel} has not been opened.  Why are we disconnecting ?????????? \n"
      end
    end
  end
end

Why is this happeing?