Fix Redis#exists deprecation warning

Gemfile.lock

@@ -444,8 +444,6 @@ GEM
       rack (>= 1.0, < 3)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
-    rack-protection (2.0.8.1)
-      rack
     rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)
@@ -570,11 +568,10 @@ GEM
       nokogiri (>= 1.8.0)
       nokogumbo (~> 2.0)
     semantic_range (2.3.0)
-    sidekiq (6.0.7)
+    sidekiq (6.1.0)
       connection_pool (>= 2.2.2)
       rack (~> 2.0)
-      rack-protection (>= 2.0.0)
-      redis (>= 4.1.0)
+      redis (>= 4.2.0)
     sidekiq-bulk (0.2.0)
       sidekiq
     sidekiq-scheduler (3.0.1)

app/lib/activitypub/activity.rb

@@ -132,7 +132,7 @@ def distribute_to_followers(status)
   end
 
   def delete_arrived_first?(uri)
-    redis.exists("delete_upon_arrival:#{@account.id}:#{uri}")
+    redis.exists?("delete_upon_arrival:#{@account.id}:#{uri}")
   end
 
   def delete_later!(uri)

app/lib/activitypub/activity/move.rb

@@ -33,7 +33,7 @@ def target_uri
   end
 
   def processed?
-    redis.exists("move_in_progress:#{@account.id}")
+    redis.exists?("move_in_progress:#{@account.id}")
   end
 
   def mark_as_processing!

app/lib/feed_manager.rb

@@ -169,7 +169,7 @@ def populate_feed(account)
   private
 
   def push_update_required?(timeline_id)
-    redis.exists("subscribed:#{timeline_id}")
+    redis.exists?("subscribed:#{timeline_id}")
   end
 
   def blocks_or_mutes?(receiver_id, account_ids, context)

app/models/home_feed.rb

@@ -8,6 +8,6 @@ def initialize(account)
   end
 
   def regenerating?
-    redis.exists("account:#{@id}:regeneration")
+    redis.exists?("account:#{@id}:regeneration")
   end
 end

app/workers/publish_announcement_reaction_worker.rb

@@ -14,7 +14,7 @@ def perform(announcement_id, name)
     payload = Oj.dump(event: :'announcement.reaction', payload: payload)
 
     FeedManager.instance.with_active_accounts do |account|
-      redis.publish("timeline:#{account.id}", payload) if redis.exists("subscribed:timeline:#{account.id}")
+      redis.publish("timeline:#{account.id}", payload) if redis.exists?("subscribed:timeline:#{account.id}")
     end
   rescue ActiveRecord::RecordNotFound
     true

app/workers/publish_scheduled_announcement_worker.rb

@@ -15,7 +15,7 @@ def perform(announcement_id)
     payload = Oj.dump(event: :announcement, payload: payload)
 
     FeedManager.instance.with_active_accounts do |account|
-      redis.publish("timeline:#{account.id}", payload) if redis.exists("subscribed:timeline:#{account.id}")
+      redis.publish("timeline:#{account.id}", payload) if redis.exists?("subscribed:timeline:#{account.id}")
     end
   end
 

app/workers/unpublish_announcement_worker.rb

@@ -8,7 +8,7 @@ def perform(announcement_id)
     payload = Oj.dump(event: :'announcement.delete', payload: announcement_id.to_s)
 
     FeedManager.instance.with_active_accounts do |account|
-      redis.publish("timeline:#{account.id}", payload) if redis.exists("subscribed:timeline:#{account.id}")
+      redis.publish("timeline:#{account.id}", payload) if redis.exists?("subscribed:timeline:#{account.id}")
     end
   end
 end

config/initializers/redis.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-Redis.exists_returns_integer = false
-
 redis_connection = Redis.new(
   url: ENV['REDIS_URL'],
   driver: :hiredis