Change emoji reaction duplication check

app/lib/activitypub/activity/like.rb

@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 
 class ActivityPub::Activity::Like < ActivityPub::Activity
+  include Redisable
+  include Lockable
+
   def perform
     @original_status = status_from_uri(object_uri)
 
@@ -44,9 +47,15 @@ class ActivityPub::Activity::Like < ActivityPub::Activity
       Trends.statuses.register(@original_status)
     end
 
-    return if EmojiReaction.where(account: @account, status: @original_status).count >= EmojiReaction::EMOJI_REACTION_PER_ACCOUNT_LIMIT
+    reaction = nil
+
+    with_redis_lock("emoji_reaction:#{@original_status.id}") do
+      return if EmojiReaction.where(account: @account, status: @original_status).count >= EmojiReaction::EMOJI_REACTION_PER_ACCOUNT_LIMIT
+      return if EmojiReaction.find_by(account: @account, status: @original_status, name: shortcode)
+
+      reaction = @original_status.emoji_reactions.create!(account: @account, name: shortcode, custom_emoji: emoji, uri: @json['id'])
+    end
 
-    reaction = @original_status.emoji_reactions.create!(account: @account, name: shortcode, custom_emoji: emoji, uri: @json['id'])
     write_stream(reaction)
 
     if @original_status.account.local?

app/models/emoji_reaction.rb

@@ -28,7 +28,6 @@ class EmojiReaction < ApplicationRecord
 
   has_one :notification, as: :activity, dependent: :destroy
 
-  validate :status_same_emoji_reaction
   validate :status_emoji_reactions_count
   validates_with EmojiReactionValidator
 

app/services/emoji_react_service.rb

@@ -4,6 +4,7 @@ class EmojiReactService < BaseService
   include Authorization
   include Payloadable
   include Redisable
+  include Lockable
 
   # React a status with emoji and notify remote user
   # @param [Account] account
@@ -14,17 +15,20 @@ class EmojiReactService < BaseService
     status = status.reblog if status.reblog? && !status.reblog.nil?
     authorize_with account, status, :emoji_reaction?
 
-    emoji_reaction = EmojiReaction.find_by(account: account, status: status, name: name)
+    emoji_reaction = nil
 
-    return emoji_reaction unless emoji_reaction.nil?
+    with_redis_lock("emoji_reaction:#{status.id}") do
+      emoji_reaction = EmojiReaction.find_by(account: account, status: status, name: name)
+      raise Mastodon::ValidationError, I18n.t('reactions.errors.duplication') unless emoji_reaction.nil?
 
-    shortcode, domain = name.split('@')
+      shortcode, domain = name.split('@')
+      custom_emoji = CustomEmoji.find_by(shortcode: shortcode, domain: domain)
+      emoji_reaction = EmojiReaction.create!(account: account, status: status, name: shortcode, custom_emoji: custom_emoji)
 
-    custom_emoji = CustomEmoji.find_by(shortcode: shortcode, domain: domain)
+      status.touch # rubocop:disable Rails/SkipsModelValidations
+    end
 
-    emoji_reaction = EmojiReaction.create!(account: account, status: status, name: shortcode, custom_emoji: custom_emoji)
-
-    status.touch # rubocop:disable Rails/SkipsModelValidations
+    raise Mastodon::ValidationError, I18n.t('reactions.errors.duplication') if emoji_reaction.nil?
 
     Trends.statuses.register(status)