The redis client from Rails.cache.data doesn't interface correctly with sets

[alexssung]

When managing redis sets using the redis client derived from Rails.cache.data, the keys associated with the created sets do not work properly for methods such as #exists #expire and #del

Example:

redis_store_client = Rails.cache.data
redis_store_client.sadd("set-test", "a")
redis_store_client.smembers("set-test")
#=> ["a"]
redis_store_client.exists("set-test")
#=> 0 (should be 1)
redis_store_client.expire("set-test", 1)
#=> false (should succeed and return true)
redis_store_client.del("set-test")
#=> 0 (should be 1)
redis_store_client.smembers("set-test")
#=> ["a"] (expire and del did not work)

# how it should work...
other_redis_client = Redis.new(host: ENV["REDIS_HOST"], port: ENV["REDIS_PORT"])
other_redis_client.sadd("set-test2", "a")
other_redis_client.smembers("set-test2")
#=> ["a"]
other_redis_client.exists("set-test2")
#=> 1
other_redis_client.expire("set-test2", 1)
#=> true
# wait 1 sec...
other_redis_client.smembers("set-test2")
#=> []

[tubbo]

Redis::Store inherits from the Redis client directly, and i don't believe we are overriding those methods, so i think this might be better suited for the redis-rb issue tracker.