Redis#exists(key)will return an Integer in redis-rb 4.3.exists?returns a boolean, you should use it instead. To opt-in to the new behavior now you can set Redis.exists_returns_integer = true. To disable this message and keep the current (boolean) behaviour of 'exists' you can setRedis.exists_returns_integer = false, but this option will be removed in 5.0. (/app/vendor/bundle/ruby/2.6.0/gems/redis-session-store-0.11.1/lib/redis-session-store.rb:70:insession_exists?
https://github.com/roidrage/redis-session-store/blob/master/lib/redis-session-store.rb#L70
Redis warns: