diff --git a/app/components/application_component.rb b/app/components/application_component.rb
index 59e84c969..0851cc41e 100644
--- a/app/components/application_component.rb
+++ b/app/components/application_component.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationComponent < ViewComponent::Base
   delegate :link_to_user, :time_ago_in_words_tagged, :format_text, :external_link_to, :tag_class, to: :helpers
   delegate :edit_icon, :delete_icon, :undelete_icon, :flag_icon, :upvote_icon, :downvote_icon, :link_icon, :sticky_icon, :unsticky_icon, to: :helpers
diff --git a/app/components/comment_votes_tooltip_component.rb b/app/components/comment_votes_tooltip_component.rb
index 4645ffe8c..2615d398e 100644
--- a/app/components/comment_votes_tooltip_component.rb
+++ b/app/components/comment_votes_tooltip_component.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This component represents the tooltip that displays when you hover over a comment's score.
 class CommentVotesTooltipComponent < ApplicationComponent
   attr_reader :comment, :current_user
diff --git a/app/components/post_gallery_component.rb b/app/components/post_gallery_component.rb
index fa330a4f6..5e74f0428 100644
--- a/app/components/post_gallery_component.rb
+++ b/app/components/post_gallery_component.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+#
 # A component that displays a gallery of post thumbnails.
 #
 # There are two types of galleries:
diff --git a/app/components/post_navbar_component.rb b/app/components/post_navbar_component.rb
index 741a8dd97..5c41fabd6 100644
--- a/app/components/post_navbar_component.rb
+++ b/app/components/post_navbar_component.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostNavbarComponent < ApplicationComponent
   extend Memoist
 
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index 0337c892a..5e2e4fac1 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class UsersController < ApplicationController
     def edit
diff --git a/app/controllers/api_keys_controller.rb b/app/controllers/api_keys_controller.rb
index d00bff79c..1793c86bc 100644
--- a/app/controllers/api_keys_controller.rb
+++ b/app/controllers/api_keys_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApiKeysController < ApplicationController
   before_action :requires_reauthentication
   respond_to :html, :json, :xml
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 2dc7d87af..4b2775887 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
   include Pundit
   helper_method :search_params
diff --git a/app/controllers/artist_commentaries_controller.rb b/app/controllers/artist_commentaries_controller.rb
index 7dc0af0bb..875a3a67c 100644
--- a/app/controllers/artist_commentaries_controller.rb
+++ b/app/controllers/artist_commentaries_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistCommentariesController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/artist_commentary_versions_controller.rb b/app/controllers/artist_commentary_versions_controller.rb
index 7b1edefea..e6d7d468a 100644
--- a/app/controllers/artist_commentary_versions_controller.rb
+++ b/app/controllers/artist_commentary_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistCommentaryVersionsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/artist_urls_controller.rb b/app/controllers/artist_urls_controller.rb
index 0c7ec5a8a..34a94cc47 100644
--- a/app/controllers/artist_urls_controller.rb
+++ b/app/controllers/artist_urls_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistUrlsController < ApplicationController
   respond_to :js, :json, :xml, :html
 
diff --git a/app/controllers/artist_versions_controller.rb b/app/controllers/artist_versions_controller.rb
index ff5a79f7d..1546916a7 100644
--- a/app/controllers/artist_versions_controller.rb
+++ b/app/controllers/artist_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistVersionsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/artists_controller.rb b/app/controllers/artists_controller.rb
index 206edfb0d..269520c91 100644
--- a/app/controllers/artists_controller.rb
+++ b/app/controllers/artists_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/autocomplete_controller.rb b/app/controllers/autocomplete_controller.rb
index 0b36168db..95df10f69 100644
--- a/app/controllers/autocomplete_controller.rb
+++ b/app/controllers/autocomplete_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AutocompleteController < ApplicationController
   respond_to :xml, :json
 
diff --git a/app/controllers/bans_controller.rb b/app/controllers/bans_controller.rb
index 3d11efa10..b484657e3 100644
--- a/app/controllers/bans_controller.rb
+++ b/app/controllers/bans_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BansController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/bulk_update_requests_controller.rb b/app/controllers/bulk_update_requests_controller.rb
index 7448e9064..33de806f4 100644
--- a/app/controllers/bulk_update_requests_controller.rb
+++ b/app/controllers/bulk_update_requests_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BulkUpdateRequestsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/comment_votes_controller.rb b/app/controllers/comment_votes_controller.rb
index e45620257..644355b33 100644
--- a/app/controllers/comment_votes_controller.rb
+++ b/app/controllers/comment_votes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentVotesController < ApplicationController
   respond_to :js, :json, :xml, :html
 
diff --git a/app/controllers/comments_controller.rb b/app/controllers/comments_controller.rb
index b2b7b290c..26b6e102c 100644
--- a/app/controllers/comments_controller.rb
+++ b/app/controllers/comments_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentsController < ApplicationController
   respond_to :html, :xml, :json, :atom
   respond_to :js, only: [:new, :update, :destroy, :undelete]
diff --git a/app/controllers/counts_controller.rb b/app/controllers/counts_controller.rb
index a685b698d..c3901ff8e 100644
--- a/app/controllers/counts_controller.rb
+++ b/app/controllers/counts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CountsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/delayed_jobs_controller.rb b/app/controllers/delayed_jobs_controller.rb
index f9164296e..d011d6476 100644
--- a/app/controllers/delayed_jobs_controller.rb
+++ b/app/controllers/delayed_jobs_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DelayedJobsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/dmails_controller.rb b/app/controllers/dmails_controller.rb
index 8df9ecef1..51ea38e0c 100644
--- a/app/controllers/dmails_controller.rb
+++ b/app/controllers/dmails_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DmailsController < ApplicationController
   respond_to :html, :xml, :js, :json
 
diff --git a/app/controllers/dtext_links_controller.rb b/app/controllers/dtext_links_controller.rb
index 23a599f7b..e63c8271f 100644
--- a/app/controllers/dtext_links_controller.rb
+++ b/app/controllers/dtext_links_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DtextLinksController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/dtext_previews_controller.rb b/app/controllers/dtext_previews_controller.rb
index 1756d6bcc..30b59d142 100644
--- a/app/controllers/dtext_previews_controller.rb
+++ b/app/controllers/dtext_previews_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DtextPreviewsController < ApplicationController
   def create
     @inline = params[:inline].to_s.truthy?
diff --git a/app/controllers/emails_controller.rb b/app/controllers/emails_controller.rb
index d22a8c050..a3e3f0fb3 100644
--- a/app/controllers/emails_controller.rb
+++ b/app/controllers/emails_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailsController < ApplicationController
   before_action :requires_reauthentication, only: [:edit, :update]
   respond_to :html, :xml, :json
diff --git a/app/controllers/explore/posts_controller.rb b/app/controllers/explore/posts_controller.rb
index 7d12924ea..f3880d81f 100644
--- a/app/controllers/explore/posts_controller.rb
+++ b/app/controllers/explore/posts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Explore
   class PostsController < ApplicationController
     respond_to :html, :xml, :json
diff --git a/app/controllers/favorite_group_orders_controller.rb b/app/controllers/favorite_group_orders_controller.rb
index b8fe161dd..121f6b89d 100644
--- a/app/controllers/favorite_group_orders_controller.rb
+++ b/app/controllers/favorite_group_orders_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoriteGroupOrdersController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/favorite_groups_controller.rb b/app/controllers/favorite_groups_controller.rb
index f221e97e5..ea112f0c4 100644
--- a/app/controllers/favorite_groups_controller.rb
+++ b/app/controllers/favorite_groups_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoriteGroupsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/favorites_controller.rb b/app/controllers/favorites_controller.rb
index 486791eb5..74f722e64 100644
--- a/app/controllers/favorites_controller.rb
+++ b/app/controllers/favorites_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoritesController < ApplicationController
   respond_to :js, :json, :html, :xml
 
diff --git a/app/controllers/forum_post_votes_controller.rb b/app/controllers/forum_post_votes_controller.rb
index b17b2dc7e..aa91915fc 100644
--- a/app/controllers/forum_post_votes_controller.rb
+++ b/app/controllers/forum_post_votes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPostVotesController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/forum_posts_controller.rb b/app/controllers/forum_posts_controller.rb
index b1ecf47e9..e6ef8ea68 100644
--- a/app/controllers/forum_posts_controller.rb
+++ b/app/controllers/forum_posts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPostsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/forum_topic_visits_controller.rb b/app/controllers/forum_topic_visits_controller.rb
index 0ae394eab..7e874df6d 100644
--- a/app/controllers/forum_topic_visits_controller.rb
+++ b/app/controllers/forum_topic_visits_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumTopicVisitsController < ApplicationController
   respond_to :xml, :json
 
diff --git a/app/controllers/forum_topics_controller.rb b/app/controllers/forum_topics_controller.rb
index 1582f83b1..f319b7610 100644
--- a/app/controllers/forum_topics_controller.rb
+++ b/app/controllers/forum_topics_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumTopicsController < ApplicationController
   respond_to :html, :xml, :json
   respond_to :atom, only: [:index, :show]
diff --git a/app/controllers/ip_addresses_controller.rb b/app/controllers/ip_addresses_controller.rb
index 657eba7d7..6d9686160 100644
--- a/app/controllers/ip_addresses_controller.rb
+++ b/app/controllers/ip_addresses_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpAddressesController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/ip_bans_controller.rb b/app/controllers/ip_bans_controller.rb
index cfeef921b..823df0fc4 100644
--- a/app/controllers/ip_bans_controller.rb
+++ b/app/controllers/ip_bans_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpBansController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/ip_geolocations_controller.rb b/app/controllers/ip_geolocations_controller.rb
index a51f9fcc4..96b52bd68 100644
--- a/app/controllers/ip_geolocations_controller.rb
+++ b/app/controllers/ip_geolocations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpGeolocationsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/iqdb_queries_controller.rb b/app/controllers/iqdb_queries_controller.rb
index f7d529256..2e89db0d4 100644
--- a/app/controllers/iqdb_queries_controller.rb
+++ b/app/controllers/iqdb_queries_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IqdbQueriesController < ApplicationController
   respond_to :html, :json, :xml, :js
 
diff --git a/app/controllers/legacy_controller.rb b/app/controllers/legacy_controller.rb
index 784b19443..479e94f7d 100644
--- a/app/controllers/legacy_controller.rb
+++ b/app/controllers/legacy_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class LegacyController < ApplicationController
   respond_to :json, :xml
 
diff --git a/app/controllers/maintenance/user/count_fixes_controller.rb b/app/controllers/maintenance/user/count_fixes_controller.rb
index c2ebd564a..ee04d98fd 100644
--- a/app/controllers/maintenance/user/count_fixes_controller.rb
+++ b/app/controllers/maintenance/user/count_fixes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Maintenance
   module User
     class CountFixesController < ApplicationController
diff --git a/app/controllers/maintenance/user/deletions_controller.rb b/app/controllers/maintenance/user/deletions_controller.rb
index 8b85bb163..be24e1830 100644
--- a/app/controllers/maintenance/user/deletions_controller.rb
+++ b/app/controllers/maintenance/user/deletions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Maintenance
   module User
     class DeletionsController < ApplicationController
diff --git a/app/controllers/maintenance/user/email_notifications_controller.rb b/app/controllers/maintenance/user/email_notifications_controller.rb
index 538133485..ca61ec3a3 100644
--- a/app/controllers/maintenance/user/email_notifications_controller.rb
+++ b/app/controllers/maintenance/user/email_notifications_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Maintenance
   module User
     class EmailNotificationsController < ApplicationController
diff --git a/app/controllers/media_assets_controller.rb b/app/controllers/media_assets_controller.rb
index b4c55007a..cdda551c7 100644
--- a/app/controllers/media_assets_controller.rb
+++ b/app/controllers/media_assets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MediaAssetsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/media_metadata_controller.rb b/app/controllers/media_metadata_controller.rb
index f7e1e4311..5ea61d0ed 100644
--- a/app/controllers/media_metadata_controller.rb
+++ b/app/controllers/media_metadata_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MediaMetadataController < ApplicationController
   respond_to :json, :xml
 
diff --git a/app/controllers/mock_services_controller.rb b/app/controllers/mock_services_controller.rb
index 69d6cad61..6d1a75292 100644
--- a/app/controllers/mock_services_controller.rb
+++ b/app/controllers/mock_services_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MockServicesController < ApplicationController
   skip_forgery_protection
   respond_to :json
diff --git a/app/controllers/mod_actions_controller.rb b/app/controllers/mod_actions_controller.rb
index 8a87c3d43..ca75db6a6 100644
--- a/app/controllers/mod_actions_controller.rb
+++ b/app/controllers/mod_actions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModActionsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/moderation_reports_controller.rb b/app/controllers/moderation_reports_controller.rb
index 95d395d1c..79fcade0e 100644
--- a/app/controllers/moderation_reports_controller.rb
+++ b/app/controllers/moderation_reports_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModerationReportsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/moderator/dashboards_controller.rb b/app/controllers/moderator/dashboards_controller.rb
index c01b67ec2..5bd5618b8 100644
--- a/app/controllers/moderator/dashboards_controller.rb
+++ b/app/controllers/moderator/dashboards_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   class DashboardsController < ApplicationController
     def show
diff --git a/app/controllers/moderator/ip_addrs_controller.rb b/app/controllers/moderator/ip_addrs_controller.rb
index 544d53040..83f92453b 100644
--- a/app/controllers/moderator/ip_addrs_controller.rb
+++ b/app/controllers/moderator/ip_addrs_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   class IpAddrsController < ApplicationController
     respond_to :html, :json
diff --git a/app/controllers/moderator/post/posts_controller.rb b/app/controllers/moderator/post/posts_controller.rb
index ab28bd2f5..f228b7e74 100644
--- a/app/controllers/moderator/post/posts_controller.rb
+++ b/app/controllers/moderator/post/posts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Post
     class PostsController < ApplicationController
diff --git a/app/controllers/modqueue_controller.rb b/app/controllers/modqueue_controller.rb
index a789e2fd9..d215e55d7 100644
--- a/app/controllers/modqueue_controller.rb
+++ b/app/controllers/modqueue_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModqueueController < ApplicationController
   respond_to :html, :json, :xml
   layout "sidebar"
diff --git a/app/controllers/news_updates_controller.rb b/app/controllers/news_updates_controller.rb
index 7e760178d..6035e970e 100644
--- a/app/controllers/news_updates_controller.rb
+++ b/app/controllers/news_updates_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewsUpdatesController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/note_previews_controller.rb b/app/controllers/note_previews_controller.rb
index e14f0b1c5..10b966a5b 100644
--- a/app/controllers/note_previews_controller.rb
+++ b/app/controllers/note_previews_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NotePreviewsController < ApplicationController
   respond_to :json
 
diff --git a/app/controllers/note_versions_controller.rb b/app/controllers/note_versions_controller.rb
index b217925f6..57638d23d 100644
--- a/app/controllers/note_versions_controller.rb
+++ b/app/controllers/note_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NoteVersionsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/notes_controller.rb b/app/controllers/notes_controller.rb
index db320a92a..54c091f17 100644
--- a/app/controllers/notes_controller.rb
+++ b/app/controllers/notes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NotesController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/password_resets_controller.rb b/app/controllers/password_resets_controller.rb
index 746f43869..ff09b5c70 100644
--- a/app/controllers/password_resets_controller.rb
+++ b/app/controllers/password_resets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PasswordResetsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/passwords_controller.rb b/app/controllers/passwords_controller.rb
index ffec5bc2a..7b47b8e1e 100644
--- a/app/controllers/passwords_controller.rb
+++ b/app/controllers/passwords_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PasswordsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/pixiv_ugoira_frame_data_controller.rb b/app/controllers/pixiv_ugoira_frame_data_controller.rb
index 5db3ea8b4..4d940138e 100644
--- a/app/controllers/pixiv_ugoira_frame_data_controller.rb
+++ b/app/controllers/pixiv_ugoira_frame_data_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PixivUgoiraFrameDataController < ApplicationController
   respond_to :json, :xml
 
diff --git a/app/controllers/pool_elements_controller.rb b/app/controllers/pool_elements_controller.rb
index cbbf8678b..e781830f9 100644
--- a/app/controllers/pool_elements_controller.rb
+++ b/app/controllers/pool_elements_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolElementsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/pool_orders_controller.rb b/app/controllers/pool_orders_controller.rb
index 7a6f4a5a6..9836db37c 100644
--- a/app/controllers/pool_orders_controller.rb
+++ b/app/controllers/pool_orders_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolOrdersController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/pool_versions_controller.rb b/app/controllers/pool_versions_controller.rb
index 7b978c3bb..567d1b577 100644
--- a/app/controllers/pool_versions_controller.rb
+++ b/app/controllers/pool_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolVersionsController < ApplicationController
   respond_to :html, :xml, :json
   before_action :check_availabililty
diff --git a/app/controllers/pools_controller.rb b/app/controllers/pools_controller.rb
index d307424ba..a48cb5963 100644
--- a/app/controllers/pools_controller.rb
+++ b/app/controllers/pools_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/post_appeals_controller.rb b/app/controllers/post_appeals_controller.rb
index 00f6bb5c5..c3924c032 100644
--- a/app/controllers/post_appeals_controller.rb
+++ b/app/controllers/post_appeals_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostAppealsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/post_approvals_controller.rb b/app/controllers/post_approvals_controller.rb
index bd5461aee..f2be0294a 100644
--- a/app/controllers/post_approvals_controller.rb
+++ b/app/controllers/post_approvals_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostApprovalsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/post_disapprovals_controller.rb b/app/controllers/post_disapprovals_controller.rb
index e470dbccf..2ac4440c1 100644
--- a/app/controllers/post_disapprovals_controller.rb
+++ b/app/controllers/post_disapprovals_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostDisapprovalsController < ApplicationController
   respond_to :js, :html, :json, :xml
 
diff --git a/app/controllers/post_events_controller.rb b/app/controllers/post_events_controller.rb
index af5e9b255..1e1c5e65e 100644
--- a/app/controllers/post_events_controller.rb
+++ b/app/controllers/post_events_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostEventsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/post_flags_controller.rb b/app/controllers/post_flags_controller.rb
index 8f5f7b20d..7ec3f729f 100644
--- a/app/controllers/post_flags_controller.rb
+++ b/app/controllers/post_flags_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostFlagsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/post_regenerations_controller.rb b/app/controllers/post_regenerations_controller.rb
index d465ac3f8..ac5c70ebd 100644
--- a/app/controllers/post_regenerations_controller.rb
+++ b/app/controllers/post_regenerations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostRegenerationsController < ApplicationController
   respond_to :xml, :json, :html
 
diff --git a/app/controllers/post_replacements_controller.rb b/app/controllers/post_replacements_controller.rb
index f878913de..3a98fb31e 100644
--- a/app/controllers/post_replacements_controller.rb
+++ b/app/controllers/post_replacements_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostReplacementsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/post_versions_controller.rb b/app/controllers/post_versions_controller.rb
index cefdc80d7..0c4fdd852 100644
--- a/app/controllers/post_versions_controller.rb
+++ b/app/controllers/post_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVersionsController < ApplicationController
   before_action :check_availabililty
   around_action :set_timeout
diff --git a/app/controllers/post_votes_controller.rb b/app/controllers/post_votes_controller.rb
index 0ef9f8f84..6e982b38c 100644
--- a/app/controllers/post_votes_controller.rb
+++ b/app/controllers/post_votes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVotesController < ApplicationController
   respond_to :js, :json, :xml, :html
 
diff --git a/app/controllers/posts_controller.rb b/app/controllers/posts_controller.rb
index f9a25f414..3a77dee0f 100644
--- a/app/controllers/posts_controller.rb
+++ b/app/controllers/posts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostsController < ApplicationController
   respond_to :html, :xml, :json, :js
   layout "sidebar"
diff --git a/app/controllers/rate_limits_controller.rb b/app/controllers/rate_limits_controller.rb
index daaa8d899..df55248f7 100644
--- a/app/controllers/rate_limits_controller.rb
+++ b/app/controllers/rate_limits_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RateLimitsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/recommended_posts_controller.rb b/app/controllers/recommended_posts_controller.rb
index c0774c02a..55ee954af 100644
--- a/app/controllers/recommended_posts_controller.rb
+++ b/app/controllers/recommended_posts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RecommendedPostsController < ApplicationController
   respond_to :html, :json, :xml, :js
 
diff --git a/app/controllers/related_tags_controller.rb b/app/controllers/related_tags_controller.rb
index 75a226401..fa647ba53 100644
--- a/app/controllers/related_tags_controller.rb
+++ b/app/controllers/related_tags_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RelatedTagsController < ApplicationController
   respond_to :json, :xml, :js, :html
 
diff --git a/app/controllers/robots_controller.rb b/app/controllers/robots_controller.rb
index 1c13acaeb..a2c33a0fd 100644
--- a/app/controllers/robots_controller.rb
+++ b/app/controllers/robots_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RobotsController < ApplicationController
   respond_to :text
 
diff --git a/app/controllers/saved_searches_controller.rb b/app/controllers/saved_searches_controller.rb
index 8d45b06fe..193340fda 100644
--- a/app/controllers/saved_searches_controller.rb
+++ b/app/controllers/saved_searches_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SavedSearchesController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index 2481ff538..7cc67b7a9 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SessionsController < ApplicationController
   respond_to :html, :json
   skip_forgery_protection only: :create, if: -> { !request.format.html? }
diff --git a/app/controllers/sources_controller.rb b/app/controllers/sources_controller.rb
index 91c5b2c9b..4dea558c4 100644
--- a/app/controllers/sources_controller.rb
+++ b/app/controllers/sources_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SourcesController < ApplicationController
   respond_to :js, :json, :xml
 
diff --git a/app/controllers/static_controller.rb b/app/controllers/static_controller.rb
index 4a8bf90ae..8061545f7 100644
--- a/app/controllers/static_controller.rb
+++ b/app/controllers/static_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StaticController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/status_controller.rb b/app/controllers/status_controller.rb
index ea4517f2c..51b55a516 100644
--- a/app/controllers/status_controller.rb
+++ b/app/controllers/status_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StatusController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/tag_aliases_controller.rb b/app/controllers/tag_aliases_controller.rb
index a677ec049..e09db77fc 100644
--- a/app/controllers/tag_aliases_controller.rb
+++ b/app/controllers/tag_aliases_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagAliasesController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/tag_implications_controller.rb b/app/controllers/tag_implications_controller.rb
index 306cfff46..1b84f8a64 100644
--- a/app/controllers/tag_implications_controller.rb
+++ b/app/controllers/tag_implications_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagImplicationsController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/tags_controller.rb b/app/controllers/tags_controller.rb
index 819adbd0d..a263a376c 100644
--- a/app/controllers/tags_controller.rb
+++ b/app/controllers/tags_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagsController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/uploads_controller.rb b/app/controllers/uploads_controller.rb
index 282373024..7174c176a 100644
--- a/app/controllers/uploads_controller.rb
+++ b/app/controllers/uploads_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadsController < ApplicationController
   respond_to :html, :xml, :json, :js
   skip_before_action :verify_authenticity_token, only: [:preprocess]
diff --git a/app/controllers/user_events_controller.rb b/app/controllers/user_events_controller.rb
index 5348fcfc5..6edfd1410 100644
--- a/app/controllers/user_events_controller.rb
+++ b/app/controllers/user_events_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserEventsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/user_feedbacks_controller.rb b/app/controllers/user_feedbacks_controller.rb
index cfea4efd0..b2fe9e97c 100644
--- a/app/controllers/user_feedbacks_controller.rb
+++ b/app/controllers/user_feedbacks_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserFeedbacksController < ApplicationController
   respond_to :html, :xml, :json, :js
 
diff --git a/app/controllers/user_name_change_requests_controller.rb b/app/controllers/user_name_change_requests_controller.rb
index 72b00c2b2..4beda8c0b 100644
--- a/app/controllers/user_name_change_requests_controller.rb
+++ b/app/controllers/user_name_change_requests_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserNameChangeRequestsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/user_sessions_controller.rb b/app/controllers/user_sessions_controller.rb
index 49446fe8b..66762300f 100644
--- a/app/controllers/user_sessions_controller.rb
+++ b/app/controllers/user_sessions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserSessionsController < ApplicationController
   respond_to :html, :json, :xml
 
diff --git a/app/controllers/user_upgrades_controller.rb b/app/controllers/user_upgrades_controller.rb
index 0a25e49fc..8bb47aefb 100644
--- a/app/controllers/user_upgrades_controller.rb
+++ b/app/controllers/user_upgrades_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserUpgradesController < ApplicationController
   respond_to :js, :html, :json, :xml
 
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 1d5ba9b47..f2bbf88e1 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UsersController < ApplicationController
   respond_to :html, :xml, :json
 
diff --git a/app/controllers/webhooks_controller.rb b/app/controllers/webhooks_controller.rb
index 3eea9a092..7e588a2f4 100644
--- a/app/controllers/webhooks_controller.rb
+++ b/app/controllers/webhooks_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WebhooksController < ApplicationController
   skip_forgery_protection only: :receive
   rescue_with Stripe::SignatureVerificationError, status: 400
diff --git a/app/controllers/wiki_page_versions_controller.rb b/app/controllers/wiki_page_versions_controller.rb
index ac9873514..b7b2d1c03 100644
--- a/app/controllers/wiki_page_versions_controller.rb
+++ b/app/controllers/wiki_page_versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WikiPageVersionsController < ApplicationController
   respond_to :html, :xml, :json
   layout "sidebar"
diff --git a/app/controllers/wiki_pages_controller.rb b/app/controllers/wiki_pages_controller.rb
index 19b5a5cd1..7386018b1 100644
--- a/app/controllers/wiki_pages_controller.rb
+++ b/app/controllers/wiki_pages_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WikiPagesController < ApplicationController
   respond_to :html, :xml, :json, :js
   layout "sidebar"
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 485f66863..0d69840df 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
   def listing_type(*fields, member_check: true, types: [:revert, :standard])
     (fields.reduce(false) { |acc, field| acc || params.dig(:search, field).present? } && (!member_check || CurrentUser.is_member?) ? types[0] : types[1])
diff --git a/app/helpers/artist_commentaries_helper.rb b/app/helpers/artist_commentaries_helper.rb
index c44ed7243..d338109cf 100644
--- a/app/helpers/artist_commentaries_helper.rb
+++ b/app/helpers/artist_commentaries_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ArtistCommentariesHelper
   def format_commentary_title(title, classes: "")
     tag.h3 do
diff --git a/app/helpers/artist_commentary_versions_helper.rb b/app/helpers/artist_commentary_versions_helper.rb
index 30d05befc..4188d35de 100644
--- a/app/helpers/artist_commentary_versions_helper.rb
+++ b/app/helpers/artist_commentary_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ArtistCommentaryVersionsHelper
   def commentary_version_field_diff(commentary_version, type, field)
     other = commentary_version.send(params[:type])
diff --git a/app/helpers/artist_versions_helper.rb b/app/helpers/artist_versions_helper.rb
index 998720d65..0322e6a33 100644
--- a/app/helpers/artist_versions_helper.rb
+++ b/app/helpers/artist_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ArtistVersionsHelper
   def artist_version_other_names_diff(artist_version, type)
     other = artist_version.send(type)
diff --git a/app/helpers/components_helper.rb b/app/helpers/components_helper.rb
index c2ca4811f..18d7ca1a8 100644
--- a/app/helpers/components_helper.rb
+++ b/app/helpers/components_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ComponentsHelper
   def post_preview(post, fit: :fixed, **options)
     render PostPreviewComponent.new(post: post, fit: fit, **options)
diff --git a/app/helpers/delayed_jobs_helper.rb b/app/helpers/delayed_jobs_helper.rb
index 19d249c27..316f0f8ba 100644
--- a/app/helpers/delayed_jobs_helper.rb
+++ b/app/helpers/delayed_jobs_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DelayedJobsHelper
   def print_name(job)
     case job.name
diff --git a/app/helpers/forum_topics_helper.rb b/app/helpers/forum_topics_helper.rb
index 6acc6c16c..b47e5aad1 100644
--- a/app/helpers/forum_topics_helper.rb
+++ b/app/helpers/forum_topics_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ForumTopicsHelper
   def forum_topic_category_select(object, field)
     select(object, field, ForumTopic.reverse_category_mapping.to_a)
diff --git a/app/helpers/icon_helper.rb b/app/helpers/icon_helper.rb
index f9532222e..9366de428 100644
--- a/app/helpers/icon_helper.rb
+++ b/app/helpers/icon_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module IconHelper
   def icon_tag(icon_class, class: nil, **options)
     klass = binding.local_variable_get(:class)
diff --git a/app/helpers/ip_addresses_helper.rb b/app/helpers/ip_addresses_helper.rb
index cee60fec9..d31200dbe 100644
--- a/app/helpers/ip_addresses_helper.rb
+++ b/app/helpers/ip_addresses_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module IpAddressesHelper
   # https://www.bing.com/maps/embed-a-map
   # https://docs.microsoft.com/en-us/bingmaps/articles/create-a-custom-map-url
diff --git a/app/helpers/note_versions_helper.rb b/app/helpers/note_versions_helper.rb
index e3a29b1fa..8cb2dcc54 100644
--- a/app/helpers/note_versions_helper.rb
+++ b/app/helpers/note_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module NoteVersionsHelper
   def note_version_position_diff(note_version, type)
     other = note_version.send(type)
diff --git a/app/helpers/pool_versions_helper.rb b/app/helpers/pool_versions_helper.rb
index 71cf87c7f..36d094ba0 100644
--- a/app/helpers/pool_versions_helper.rb
+++ b/app/helpers/pool_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PoolVersionsHelper
   def pool_version_show_diff(pool_version, type)
     other = pool_version.send(type)
diff --git a/app/helpers/popular_posts_helper.rb b/app/helpers/popular_posts_helper.rb
index 5a80afd64..0af2847bb 100644
--- a/app/helpers/popular_posts_helper.rb
+++ b/app/helpers/popular_posts_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PopularPostsHelper
   def next_date_for_scale(date, scale)
     case scale
diff --git a/app/helpers/post_versions_helper.rb b/app/helpers/post_versions_helper.rb
index 0f4d9eaaf..1f7ff7529 100644
--- a/app/helpers/post_versions_helper.rb
+++ b/app/helpers/post_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PostVersionsHelper
   def post_version_diff(post_version, type)
     return "" if type == "previous" && post_version.version == 1
@@ -22,7 +24,7 @@ module PostVersionsHelper
       obsolete_added_tags = added_tags - other_tags
       obsolete_removed_tags = removed_tags & other_tags
     end
-    html = '<span class="diff-list">'
+    html = '<span class="diff-list">'.dup
 
     added_tags.each do |tag|
       obsolete_class = (obsolete_added_tags.include?(tag) ? "diff-obsolete" : "")
diff --git a/app/helpers/posts_helper.rb b/app/helpers/posts_helper.rb
index 9a0bfe151..a759d02e3 100644
--- a/app/helpers/posts_helper.rb
+++ b/app/helpers/posts_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PostsHelper
   def reportbooru_enabled?
     Danbooru.config.reportbooru_server.present? && Danbooru.config.reportbooru_key.present?
diff --git a/app/helpers/seo_helper.rb b/app/helpers/seo_helper.rb
index 39e58a2c5..faedbe148 100644
--- a/app/helpers/seo_helper.rb
+++ b/app/helpers/seo_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # https://yoast.com/structured-data-schema-ultimate-guide/
 # https://technicalseo.com/tools/schema-markup-generator/
 # https://developers.google.com/search/docs/data-types/sitelinks-searchbox
diff --git a/app/helpers/tags_helper.rb b/app/helpers/tags_helper.rb
index d6e8a9728..178914799 100644
--- a/app/helpers/tags_helper.rb
+++ b/app/helpers/tags_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module TagsHelper
   def tag_class(tag)
     return nil if tag.blank?
diff --git a/app/helpers/uploads_helper.rb b/app/helpers/uploads_helper.rb
index 34e38e7bb..7a9b010db 100644
--- a/app/helpers/uploads_helper.rb
+++ b/app/helpers/uploads_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module UploadsHelper
   def render_status(upload)
     case upload.status
diff --git a/app/helpers/user_upgrades_helper.rb b/app/helpers/user_upgrades_helper.rb
index 8d37de45d..c3f7b1116 100644
--- a/app/helpers/user_upgrades_helper.rb
+++ b/app/helpers/user_upgrades_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module UserUpgradesHelper
   def cents_to_usd(cents)
     number_to_currency(cents / 100, precision: 0)
diff --git a/app/helpers/users_helper.rb b/app/helpers/users_helper.rb
index 68526187e..6aab63a81 100644
--- a/app/helpers/users_helper.rb
+++ b/app/helpers/users_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module UsersHelper
   def unread_dmail_indicator(user)
     "(#{user.unread_dmail_count})" if user.unread_dmail_count > 0
diff --git a/app/helpers/wiki_page_versions_helper.rb b/app/helpers/wiki_page_versions_helper.rb
index 221dd3d74..cc7746426 100644
--- a/app/helpers/wiki_page_versions_helper.rb
+++ b/app/helpers/wiki_page_versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module WikiPageVersionsHelper
   def wiki_version_show_diff(wiki_page_version, type)
     other = wiki_page_version.send(type)
diff --git a/app/helpers/wiki_pages_helper.rb b/app/helpers/wiki_pages_helper.rb
index 7eee278c2..003f5861c 100644
--- a/app/helpers/wiki_pages_helper.rb
+++ b/app/helpers/wiki_pages_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module WikiPagesHelper
   def wiki_page_other_names_list(wiki_page)
     names_html = wiki_page.other_names.map do |name|
diff --git a/app/jobs/amcheck_database_job.rb b/app/jobs/amcheck_database_job.rb
index 388f79da9..d4f5df0c9 100644
--- a/app/jobs/amcheck_database_job.rb
+++ b/app/jobs/amcheck_database_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs hourly to check the database for corruption. Spawned by {DanbooruMaintenance}.
 # Requires at least PostgreSQL 14.0 to be installed for pg_amcheck to be available.
 #
diff --git a/app/jobs/application_job.rb b/app/jobs/application_job.rb
index 8fff312fe..1781f55eb 100644
--- a/app/jobs/application_job.rb
+++ b/app/jobs/application_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # The base class for all background jobs on Danbooru.
 #
 # @see https://guides.rubyonrails.org/active_job_basics.html
diff --git a/app/jobs/bigquery_export_all_job.rb b/app/jobs/bigquery_export_all_job.rb
index 195734ff0..21b00daa4 100644
--- a/app/jobs/bigquery_export_all_job.rb
+++ b/app/jobs/bigquery_export_all_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to export all tables to BigQuery. Spawned by {DanbooruMaintenance}.
 class BigqueryExportAllJob < ApplicationJob
   def perform
diff --git a/app/jobs/bigquery_export_job.rb b/app/jobs/bigquery_export_job.rb
index 8add5f928..e14a6db6e 100644
--- a/app/jobs/bigquery_export_job.rb
+++ b/app/jobs/bigquery_export_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that exports a database table to Google Cloud Storage and to Google
 # BigQuery. Spawned daily by {DanbooruMaintenance}.
 #
diff --git a/app/jobs/delete_favorites_job.rb b/app/jobs/delete_favorites_job.rb
index 83890e84d..d1635b06e 100644
--- a/app/jobs/delete_favorites_job.rb
+++ b/app/jobs/delete_favorites_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that deletes a user's favorites when they delete their account.
 class DeleteFavoritesJob < ApplicationJob
   queue_as :default
diff --git a/app/jobs/discord_notification_job.rb b/app/jobs/discord_notification_job.rb
index 3b9edc1be..56c3ef584 100644
--- a/app/jobs/discord_notification_job.rb
+++ b/app/jobs/discord_notification_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that sends notifications about new forum posts to Discord. Spawned by
 # the {ForumPost} class when a new forum post is created.
 class DiscordNotificationJob < ApplicationJob
diff --git a/app/jobs/dmail_inactive_approvers_job.rb b/app/jobs/dmail_inactive_approvers_job.rb
index 588ef2ecd..e2b9ff134 100644
--- a/app/jobs/dmail_inactive_approvers_job.rb
+++ b/app/jobs/dmail_inactive_approvers_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs weekly to warn inactive approvers before they're demoted.
 # Spawned by {DanbooruMaintenance}.
 class DmailInactiveApproversJob < ApplicationJob
diff --git a/app/jobs/iqdb_add_post_job.rb b/app/jobs/iqdb_add_post_job.rb
index e94b61cd2..0a38dae28 100644
--- a/app/jobs/iqdb_add_post_job.rb
+++ b/app/jobs/iqdb_add_post_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that adds a post to IQDB when a new post is uploaded, or when a post is
 # regenerated. Spawned by the {Post} class.
 class IqdbAddPostJob < ApplicationJob
diff --git a/app/jobs/iqdb_remove_post_job.rb b/app/jobs/iqdb_remove_post_job.rb
index 40832c79b..fa4244816 100644
--- a/app/jobs/iqdb_remove_post_job.rb
+++ b/app/jobs/iqdb_remove_post_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that removes a post from IQDB when it is deleted. Spawned by the {Post}
 # class.
 class IqdbRemovePostJob < ApplicationJob
diff --git a/app/jobs/populate_saved_search_job.rb b/app/jobs/populate_saved_search_job.rb
index 8a93a45a4..08434876f 100644
--- a/app/jobs/populate_saved_search_job.rb
+++ b/app/jobs/populate_saved_search_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that updates a user's saved searches when they do a search for
 # `search:all` or `search:<label>`.
 class PopulateSavedSearchJob < ApplicationJob
diff --git a/app/jobs/process_bulk_update_request_job.rb b/app/jobs/process_bulk_update_request_job.rb
index 6e1f05785..93fde017e 100644
--- a/app/jobs/process_bulk_update_request_job.rb
+++ b/app/jobs/process_bulk_update_request_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that applies a bulk update request after it is approved.
 #
 # @see {BulkUpdateRequestProcessor}
diff --git a/app/jobs/prune_approvers_job.rb b/app/jobs/prune_approvers_job.rb
index 5dcc80411..099397477 100644
--- a/app/jobs/prune_approvers_job.rb
+++ b/app/jobs/prune_approvers_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs monthly to demote all inactive approvers. Spawned by
 # {DanbooruMaintenance}.
 class PruneApproversJob < ApplicationJob
diff --git a/app/jobs/prune_bans_job.rb b/app/jobs/prune_bans_job.rb
index 952ea96bd..ac374d6a8 100644
--- a/app/jobs/prune_bans_job.rb
+++ b/app/jobs/prune_bans_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to remove expired bans. Spawned by
 # {DanbooruMaintenance}.
 class PruneBansJob < ApplicationJob
diff --git a/app/jobs/prune_bulk_update_requests_job.rb b/app/jobs/prune_bulk_update_requests_job.rb
index 5d6fdfb39..621503b19 100644
--- a/app/jobs/prune_bulk_update_requests_job.rb
+++ b/app/jobs/prune_bulk_update_requests_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to reject expired bulk update requests. Spawned by
 # {DanbooruMaintenance}.
 class PruneBulkUpdateRequestsJob < ApplicationJob
diff --git a/app/jobs/prune_delayed_jobs_job.rb b/app/jobs/prune_delayed_jobs_job.rb
index caa986b6f..2474c6589 100644
--- a/app/jobs/prune_delayed_jobs_job.rb
+++ b/app/jobs/prune_delayed_jobs_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to delete all stale delayed jobs. Spawned by
 # {DanbooruMaintenance}.
 class PruneDelayedJobsJob < ApplicationJob
diff --git a/app/jobs/prune_post_disapprovals_job.rb b/app/jobs/prune_post_disapprovals_job.rb
index f26f12e6a..6ed081745 100644
--- a/app/jobs/prune_post_disapprovals_job.rb
+++ b/app/jobs/prune_post_disapprovals_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to remove old post disapprovals. Spawned by
 # {DanbooruMaintenance}.
 class PrunePostDisapprovalsJob < ApplicationJob
diff --git a/app/jobs/prune_posts_job.rb b/app/jobs/prune_posts_job.rb
index 2fcab7739..ed697b523 100644
--- a/app/jobs/prune_posts_job.rb
+++ b/app/jobs/prune_posts_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs hourly to delete all expired pending, flagged, and appealed
 # posts. Spawned by {DanbooruMaintenance}.
 class PrunePostsJob < ApplicationJob
diff --git a/app/jobs/prune_rate_limits_job.rb b/app/jobs/prune_rate_limits_job.rb
index d9291d981..4450b58c9 100644
--- a/app/jobs/prune_rate_limits_job.rb
+++ b/app/jobs/prune_rate_limits_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs hourly to delete all state rate limit objects from the
 # database. Spawned by {DanbooruMaintenance}.
 class PruneRateLimitsJob < ApplicationJob
diff --git a/app/jobs/prune_uploads_job.rb b/app/jobs/prune_uploads_job.rb
index 378abf2a6..a5df65bbc 100644
--- a/app/jobs/prune_uploads_job.rb
+++ b/app/jobs/prune_uploads_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs hourly to delete all completed, stale, or failed uploads.
 # Spawned by {DanbooruMaintenance}.
 class PruneUploadsJob < ApplicationJob
diff --git a/app/jobs/regenerate_post_counts_job.rb b/app/jobs/regenerate_post_counts_job.rb
index 0cd7e9bc0..714a1216d 100644
--- a/app/jobs/regenerate_post_counts_job.rb
+++ b/app/jobs/regenerate_post_counts_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs hourly to fix all incorrect tag counts.
 # Spawned by {DanbooruMaintenance}.
 class RegeneratePostCountsJob < ApplicationJob
diff --git a/app/jobs/regenerate_post_job.rb b/app/jobs/regenerate_post_job.rb
index da6cb6981..539b8a6ec 100644
--- a/app/jobs/regenerate_post_job.rb
+++ b/app/jobs/regenerate_post_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that regenerates a post's images and IQDB when a moderator requests it.
 class RegeneratePostJob < ApplicationJob
   queue_as :default
diff --git a/app/jobs/retire_tag_relationships_job.rb b/app/jobs/retire_tag_relationships_job.rb
index 7b2e64f7f..ad4bd6e2e 100644
--- a/app/jobs/retire_tag_relationships_job.rb
+++ b/app/jobs/retire_tag_relationships_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs weekly to retire inactive aliases and implications. Spawned
 # by {DanbooruMaintenance}.
 class RetireTagRelationshipsJob < ApplicationJob
diff --git a/app/jobs/upload_preprocessor_delayed_start_job.rb b/app/jobs/upload_preprocessor_delayed_start_job.rb
index acc31da65..d0ea808fe 100644
--- a/app/jobs/upload_preprocessor_delayed_start_job.rb
+++ b/app/jobs/upload_preprocessor_delayed_start_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that downloads and generates thumbnails in the background for an image
 # uploaded with the upload bookmarklet.
 class UploadPreprocessorDelayedStartJob < ApplicationJob
diff --git a/app/jobs/upload_service_delayed_start_job.rb b/app/jobs/upload_service_delayed_start_job.rb
index 45c65663f..ff910e595 100644
--- a/app/jobs/upload_service_delayed_start_job.rb
+++ b/app/jobs/upload_service_delayed_start_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that tries to resume a preprocessed image upload job.
 class UploadServiceDelayedStartJob < ApplicationJob
   queue_as :default
diff --git a/app/jobs/vacuum_database_job.rb b/app/jobs/vacuum_database_job.rb
index 34eb521b1..690f79c0e 100644
--- a/app/jobs/vacuum_database_job.rb
+++ b/app/jobs/vacuum_database_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A job that runs daily to vacuum the database. Spawned by {DanbooruMaintenance}.
 class VacuumDatabaseJob < ApplicationJob
   def perform
diff --git a/app/logical/application_responder.rb b/app/logical/application_responder.rb
index df8290306..3e56541bd 100644
--- a/app/logical/application_responder.rb
+++ b/app/logical/application_responder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Hooks into `respond_with` to add some custom behavior, including support for
 # the `expires_in`, `expiry`, and `only` params.
 #
diff --git a/app/logical/approver_pruner.rb b/app/logical/approver_pruner.rb
index c494aa688..2d202b9bc 100644
--- a/app/logical/approver_pruner.rb
+++ b/app/logical/approver_pruner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Demote all approvers who haven't approved at least 30 posts in the last 45
 # days. Moderators and recently promoted approvers are exempt. Runs as a monthly
 # maintenance task. Approvers who are facing demotion are sent a weekly warning
diff --git a/app/logical/artist_finder.rb b/app/logical/artist_finder.rb
index a29be49c8..52d3d6e48 100644
--- a/app/logical/artist_finder.rb
+++ b/app/logical/artist_finder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Find the artist entry for a given artist profile URL.
 module ArtistFinder
   module_function
diff --git a/app/logical/autocomplete_service.rb b/app/logical/autocomplete_service.rb
index f747d4513..c4012dfd9 100644
--- a/app/logical/autocomplete_service.rb
+++ b/app/logical/autocomplete_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Autocomplete tags, usernames, pools, and more.
 #
 # @example
diff --git a/app/logical/bigquery_export_service.rb b/app/logical/bigquery_export_service.rb
index 076957ed5..2bef818f9 100644
--- a/app/logical/bigquery_export_service.rb
+++ b/app/logical/bigquery_export_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Perform a daily database dump to BigQuery and to Google Cloud Storage. This
 # contains all data visible to anonymous users.
 #
diff --git a/app/logical/bulk_update_request_processor.rb b/app/logical/bulk_update_request_processor.rb
index cf2e5b512..1906240d2 100644
--- a/app/logical/bulk_update_request_processor.rb
+++ b/app/logical/bulk_update_request_processor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Process a bulk update request. Parses the request and applies each line in
 # sequence.
 class BulkUpdateRequestProcessor
diff --git a/app/logical/bulk_update_request_pruner.rb b/app/logical/bulk_update_request_pruner.rb
index 113544785..ff4824e47 100644
--- a/app/logical/bulk_update_request_pruner.rb
+++ b/app/logical/bulk_update_request_pruner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Rejects bulk update requests that haven't been approved in 45 days.
 module BulkUpdateRequestPruner
   module_function
diff --git a/app/logical/cache.rb b/app/logical/cache.rb
index 459d063da..8c875269e 100644
--- a/app/logical/cache.rb
+++ b/app/logical/cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A wrapper around `Rails.cache` that adds some extra helper methods. All
 # Danbooru code should use this class instead of using `Rails.cache` directly.
 #
diff --git a/app/logical/cloudflare_service.rb b/app/logical/cloudflare_service.rb
index 585b43ac2..5f450face 100644
--- a/app/logical/cloudflare_service.rb
+++ b/app/logical/cloudflare_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A simple Cloudflare API client for purging cached images after they're
 # regenerated or deleted.
 class CloudflareService
diff --git a/app/logical/color_palette.rb b/app/logical/color_palette.rb
index abe75562c..049b7f67a 100644
--- a/app/logical/color_palette.rb
+++ b/app/logical/color_palette.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Generates a set of CSS variables for site's color palette.
 #
 # The CSS variables are named like `var(--{hue}-{i})`, where `hue` is the color
diff --git a/app/logical/concerns/array_attribute.rb b/app/logical/concerns/array_attribute.rb
index 128e4f288..597a8fe06 100644
--- a/app/logical/concerns/array_attribute.rb
+++ b/app/logical/concerns/array_attribute.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ArrayAttribute
   extend ActiveSupport::Concern
 
diff --git a/app/logical/concerns/deletable.rb b/app/logical/concerns/deletable.rb
index f7a1a8f3b..57f60a981 100644
--- a/app/logical/concerns/deletable.rb
+++ b/app/logical/concerns/deletable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A concern that adds common helper methods to models that are soft deletable.
 #
 # @example
diff --git a/app/logical/concerns/has_bit_flags.rb b/app/logical/concerns/has_bit_flags.rb
index 9364c042f..fe00b0d6b 100644
--- a/app/logical/concerns/has_bit_flags.rb
+++ b/app/logical/concerns/has_bit_flags.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module HasBitFlags
   extend ActiveSupport::Concern
 
diff --git a/app/logical/concerns/mentionable.rb b/app/logical/concerns/mentionable.rb
index e61b29cd7..3e26ced21 100644
--- a/app/logical/concerns/mentionable.rb
+++ b/app/logical/concerns/mentionable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A concern that handles @mentions in comments and forum posts. Sends a DMail
 # to mentioned users when a comment or forum post is created or edited to add
 # new mentions.
diff --git a/app/logical/concerns/normalizable.rb b/app/logical/concerns/normalizable.rb
index e3b1b54d2..7b388029a 100644
--- a/app/logical/concerns/normalizable.rb
+++ b/app/logical/concerns/normalizable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Normalizable
   extend ActiveSupport::Concern
 
diff --git a/app/logical/concerns/searchable.rb b/app/logical/concerns/searchable.rb
index a18fd41e9..e93234e93 100644
--- a/app/logical/concerns/searchable.rb
+++ b/app/logical/concerns/searchable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Searchable
   extend ActiveSupport::Concern
 
diff --git a/app/logical/current_user.rb b/app/logical/current_user.rb
index 0ca78ce4f..ce856e55e 100644
--- a/app/logical/current_user.rb
+++ b/app/logical/current_user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A global variable containing the current user, the current IP address, the
 # current user's country code, whether safe mode is enabled, and whether
 # save-data mode is enabled.
diff --git a/app/logical/d_text.rb b/app/logical/d_text.rb
index 9da6bf7ae..664ab29ba 100644
--- a/app/logical/d_text.rb
+++ b/app/logical/d_text.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'cgi'
 require 'uri'
 
diff --git a/app/logical/danbooru/helpers.rb b/app/logical/danbooru/helpers.rb
index 9bfa2758f..9b5fe431d 100644
--- a/app/logical/danbooru/helpers.rb
+++ b/app/logical/danbooru/helpers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   module Helpers
     module_function
diff --git a/app/logical/danbooru/http.rb b/app/logical/danbooru/http.rb
index a5f62d90a..0bd59c650 100644
--- a/app/logical/danbooru/http.rb
+++ b/app/logical/danbooru/http.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "danbooru/http/application_client"
 require "danbooru/http/html_adapter"
 require "danbooru/http/xml_adapter"
diff --git a/app/logical/danbooru/http/application_client.rb b/app/logical/danbooru/http/application_client.rb
index 27ac6a6d1..318851009 100644
--- a/app/logical/danbooru/http/application_client.rb
+++ b/app/logical/danbooru/http/application_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An extension to HTTP::Client that lets us write Rack-style middlewares that
 # hook into the request/response cycle and override how requests are made. This
 # works by extending http.rb's concept of features (HTTP::Feature) to give them
diff --git a/app/logical/danbooru/http/cache.rb b/app/logical/danbooru/http/cache.rb
index 43932bd28..38b4e4f18 100644
--- a/app/logical/danbooru/http/cache.rb
+++ b/app/logical/danbooru/http/cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Cache < HTTP::Feature
diff --git a/app/logical/danbooru/http/html_adapter.rb b/app/logical/danbooru/http/html_adapter.rb
index 72a3a5b39..c23f90ffb 100644
--- a/app/logical/danbooru/http/html_adapter.rb
+++ b/app/logical/danbooru/http/html_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class HtmlAdapter < HTTP::MimeType::Adapter
diff --git a/app/logical/danbooru/http/logger.rb b/app/logical/danbooru/http/logger.rb
index 427e92806..907753f15 100644
--- a/app/logical/danbooru/http/logger.rb
+++ b/app/logical/danbooru/http/logger.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Logger < HTTP::Feature
diff --git a/app/logical/danbooru/http/redirector.rb b/app/logical/danbooru/http/redirector.rb
index 6bb992ee2..95d9b9171 100644
--- a/app/logical/danbooru/http/redirector.rb
+++ b/app/logical/danbooru/http/redirector.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A HTTP::Feature that automatically follows HTTP redirects.
 #
 # @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections
diff --git a/app/logical/danbooru/http/retriable.rb b/app/logical/danbooru/http/retriable.rb
index c94af963a..9a2d98c33 100644
--- a/app/logical/danbooru/http/retriable.rb
+++ b/app/logical/danbooru/http/retriable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A HTTP::Feature that automatically retries requests that return a 429 error
 # or a Retry-After header.
 #
diff --git a/app/logical/danbooru/http/session.rb b/app/logical/danbooru/http/session.rb
index 3bb532928..99354373c 100644
--- a/app/logical/danbooru/http/session.rb
+++ b/app/logical/danbooru/http/session.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Session < HTTP::Feature
diff --git a/app/logical/danbooru/http/spoof_referrer.rb b/app/logical/danbooru/http/spoof_referrer.rb
index 7df6faef9..a93daf31a 100644
--- a/app/logical/danbooru/http/spoof_referrer.rb
+++ b/app/logical/danbooru/http/spoof_referrer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class SpoofReferrer < HTTP::Feature
diff --git a/app/logical/danbooru/http/unpolish_cloudflare.rb b/app/logical/danbooru/http/unpolish_cloudflare.rb
index 1f671c356..edd909495 100644
--- a/app/logical/danbooru/http/unpolish_cloudflare.rb
+++ b/app/logical/danbooru/http/unpolish_cloudflare.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Detect sites using Cloudflare Polish and bypass it by adding a random
 # cache-busting URL param.
 #
diff --git a/app/logical/danbooru/http/xml_adapter.rb b/app/logical/danbooru/http/xml_adapter.rb
index 70c901c07..002841612 100644
--- a/app/logical/danbooru/http/xml_adapter.rb
+++ b/app/logical/danbooru/http/xml_adapter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class XmlAdapter < HTTP::MimeType::Adapter
diff --git a/app/logical/danbooru/ip_address.rb b/app/logical/danbooru/ip_address.rb
index 0026ea91d..7e887fbcb 100644
--- a/app/logical/danbooru/ip_address.rb
+++ b/app/logical/danbooru/ip_address.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A wrapper around the IPAddress gem that adds some extra utility methods.
 #
 # @see https://github.com/ipaddress-gem/ipaddress
diff --git a/app/logical/danbooru/message_verifier.rb b/app/logical/danbooru/message_verifier.rb
index aac80fa0a..e5ebafeca 100644
--- a/app/logical/danbooru/message_verifier.rb
+++ b/app/logical/danbooru/message_verifier.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class MessageVerifier
     attr_reader :purpose, :secret, :verifier
diff --git a/app/logical/danbooru_logger.rb b/app/logical/danbooru_logger.rb
index 4728a3b71..64d5a800e 100644
--- a/app/logical/danbooru_logger.rb
+++ b/app/logical/danbooru_logger.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # The DanbooruLogger class handles logging messages to the Rails log and to NewRelic.
 #
 # @see https://guides.rubyonrails.org/debugging_rails_applications.html#the-logger
diff --git a/app/logical/danbooru_maintenance.rb b/app/logical/danbooru_maintenance.rb
index cf15cec2b..2a399e67c 100644
--- a/app/logical/danbooru_maintenance.rb
+++ b/app/logical/danbooru_maintenance.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DanbooruMaintenance
   module_function
 
diff --git a/app/logical/deep_danbooru_client.rb b/app/logical/deep_danbooru_client.rb
index c1c256f9c..26da348fe 100644
--- a/app/logical/deep_danbooru_client.rb
+++ b/app/logical/deep_danbooru_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeepDanbooruClient
   attr_reader :http
 
diff --git a/app/logical/deviant_art_api_client.rb b/app/logical/deviant_art_api_client.rb
index 4b5fd3139..e8372ee3e 100644
--- a/app/logical/deviant_art_api_client.rb
+++ b/app/logical/deviant_art_api_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A DeviantArt API client.
 #
 # Authentication is via OAuth2 with the client credentials grant. Register a
diff --git a/app/logical/diff_builder.rb b/app/logical/diff_builder.rb
index 073f5a1a9..33b93b950 100644
--- a/app/logical/diff_builder.rb
+++ b/app/logical/diff_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Builds an HTML diff between two pieces of text.
 class DiffBuilder
   attr_reader :this_text, :that_text, :pattern
diff --git a/app/logical/discord_api_client.rb b/app/logical/discord_api_client.rb
index c2a2aab9f..dd42f089b 100644
--- a/app/logical/discord_api_client.rb
+++ b/app/logical/discord_api_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A Discord API Client.
 #
 # @see https://discord.com/developers/docs/intro
diff --git a/app/logical/discord_slash_command.rb b/app/logical/discord_slash_command.rb
index 78ffbd11e..2a0cc24df 100644
--- a/app/logical/discord_slash_command.rb
+++ b/app/logical/discord_slash_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # The parent class for a Discord slash command. Each slash command handled by
 # Danbooru is a subclass of this class. Subclasses should set the {#name},
 # {#description}, and {#options} class attributes defining the slash command's
diff --git a/app/logical/discord_slash_command/count_command.rb b/app/logical/discord_slash_command/count_command.rb
index c81739baa..beca11e5f 100644
--- a/app/logical/discord_slash_command/count_command.rb
+++ b/app/logical/discord_slash_command/count_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class CountCommand < DiscordSlashCommand
     self.name = "count"
diff --git a/app/logical/discord_slash_command/post_embed.rb b/app/logical/discord_slash_command/post_embed.rb
index 302057d86..419b9ba96 100644
--- a/app/logical/discord_slash_command/post_embed.rb
+++ b/app/logical/discord_slash_command/post_embed.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostEmbed
     attr_reader :post, :command
diff --git a/app/logical/discord_slash_command/posts_command.rb b/app/logical/discord_slash_command/posts_command.rb
index ae604efe4..2efb0e96f 100644
--- a/app/logical/discord_slash_command/posts_command.rb
+++ b/app/logical/discord_slash_command/posts_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostsCommand < DiscordSlashCommand
     extend Memoist
diff --git a/app/logical/discord_slash_command/random_command.rb b/app/logical/discord_slash_command/random_command.rb
index be8931039..854cf5f6b 100644
--- a/app/logical/discord_slash_command/random_command.rb
+++ b/app/logical/discord_slash_command/random_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class RandomCommand < DiscordSlashCommand
     self.name = "random"
diff --git a/app/logical/discord_slash_command/tagme_command.rb b/app/logical/discord_slash_command/tagme_command.rb
index 23b974d66..9ab1215af 100644
--- a/app/logical/discord_slash_command/tagme_command.rb
+++ b/app/logical/discord_slash_command/tagme_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TagmeCommand < DiscordSlashCommand
     self.name = "tagme"
diff --git a/app/logical/discord_slash_command/time_command.rb b/app/logical/discord_slash_command/time_command.rb
index e96b2bc32..949d55cba 100644
--- a/app/logical/discord_slash_command/time_command.rb
+++ b/app/logical/discord_slash_command/time_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TimeCommand < DiscordSlashCommand
     self.name = "time"
diff --git a/app/logical/discord_slash_command/wiki_command.rb b/app/logical/discord_slash_command/wiki_command.rb
index a7acacac1..c0112c66d 100644
--- a/app/logical/discord_slash_command/wiki_command.rb
+++ b/app/logical/discord_slash_command/wiki_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class WikiCommand < DiscordSlashCommand
     extend Memoist
diff --git a/app/logical/discord_webhook_service.rb b/app/logical/discord_webhook_service.rb
index b1864e32c..815a3d9e5 100644
--- a/app/logical/discord_webhook_service.rb
+++ b/app/logical/discord_webhook_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Used for posting notifications to Discord about new forum posts.
 # https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks
 
diff --git a/app/logical/dtext_input.rb b/app/logical/dtext_input.rb
index 687e99eef..c0a2a9d98 100644
--- a/app/logical/dtext_input.rb
+++ b/app/logical/dtext_input.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A custom SimpleForm input for DText fields.
 #
 # Usage:
diff --git a/app/logical/duration_parser.rb b/app/logical/duration_parser.rb
index 9674dd70c..3f2aae975 100644
--- a/app/logical/duration_parser.rb
+++ b/app/logical/duration_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'abbrev'
 
 module DurationParser
diff --git a/app/logical/email_validator.rb b/app/logical/email_validator.rb
index b93991f22..5219116d7 100644
--- a/app/logical/email_validator.rb
+++ b/app/logical/email_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'resolv'
 
 # Validates that an email address is well-formed, is deliverable, and is not a
diff --git a/app/logical/explain_parser.rb b/app/logical/explain_parser.rb
index 65b7f3564..c2f0ac265 100644
--- a/app/logical/explain_parser.rb
+++ b/app/logical/explain_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Parse the output of the Postgres EXPLAIN command to get how many rows Postgres
 # *thinks* a SQL query will return. This is an estimate, and only accurate for
 # queries that have a single condition. If the query has multiple conditions,
diff --git a/app/logical/ffmpeg.rb b/app/logical/ffmpeg.rb
index 2d962331e..304f50ed8 100644
--- a/app/logical/ffmpeg.rb
+++ b/app/logical/ffmpeg.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "shellwords"
 
 # A wrapper for the ffmpeg command.
diff --git a/app/logical/forum_updater.rb b/app/logical/forum_updater.rb
index 7d2f66f85..a2a24cbd5 100644
--- a/app/logical/forum_updater.rb
+++ b/app/logical/forum_updater.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Add a post to a forum topic.
 class ForumUpdater
   attr_reader :forum_topic
diff --git a/app/logical/image_proxy.rb b/app/logical/image_proxy.rb
index 597d1210f..2dcc53acc 100644
--- a/app/logical/image_proxy.rb
+++ b/app/logical/image_proxy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ImageProxy
   class Error < StandardError; end
 
diff --git a/app/logical/ip_address_type.rb b/app/logical/ip_address_type.rb
index e633be55b..f947c1e2e 100644
--- a/app/logical/ip_address_type.rb
+++ b/app/logical/ip_address_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Ensure ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Inet is loaded in
 # the dev environment when eager loading is disabled.
 require "active_record/connection_adapters/postgresql_adapter"
diff --git a/app/logical/ip_lookup.rb b/app/logical/ip_lookup.rb
index 2d5cbf9ef..e2ac62c39 100644
--- a/app/logical/ip_lookup.rb
+++ b/app/logical/ip_lookup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for https://ipregistry.co. Looks up IP address information,
 # including the geolocation and whether the IP is a proxy.
 #
diff --git a/app/logical/iqdb_client.rb b/app/logical/iqdb_client.rb
index d27f95698..dc11d3d92 100644
--- a/app/logical/iqdb_client.rb
+++ b/app/logical/iqdb_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for Danbooru's internal IQDB instance. Can add images, remove
 # images, and search for images in IQDB.
 #
diff --git a/app/logical/mastodon_api_client.rb b/app/logical/mastodon_api_client.rb
index a8a40c36c..a2de2c6a7 100644
--- a/app/logical/mastodon_api_client.rb
+++ b/app/logical/mastodon_api_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for Mastodon.
 #
 # @see https://docs.joinmastodon.org/api
@@ -50,7 +52,7 @@ class MastodonApiClient
   end
 
   def commentary
-    commentary = ""
+    commentary = "".dup
     commentary << "<p>#{json["spoiler_text"]}</p>" if json["spoiler_text"].present?
     commentary << json["content"] if json["content"].present?
     commentary
diff --git a/app/logical/media_file.rb b/app/logical/media_file.rb
index 8ca597acf..1b846319e 100644
--- a/app/logical/media_file.rb
+++ b/app/logical/media_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A MediaFile represents an image, video, or flash file. It contains methods for
 # detecting the file type, for generating a preview image, for getting metadata,
 # and for resizing images.
diff --git a/app/logical/media_file/flash.rb b/app/logical/media_file/flash.rb
index b3d3815ae..b6f29d309 100644
--- a/app/logical/media_file/flash.rb
+++ b/app/logical/media_file/flash.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file contains code derived from
 # https://github.com/dim/ruby-imagespec/blob/f2f3ce8bb5b1b411f8658e66a891a095261d94c0/lib/image_spec/parser/swf.rb
 #
diff --git a/app/logical/media_file/image.rb b/app/logical/media_file/image.rb
index 156b582e9..453fffd8a 100644
--- a/app/logical/media_file/image.rb
+++ b/app/logical/media_file/image.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A MediaFile for a JPEG, PNG, or GIF file. Uses libvips for resizing images.
 #
 # @see https://github.com/libvips/ruby-vips
diff --git a/app/logical/media_file/ugoira.rb b/app/logical/media_file/ugoira.rb
index b7977f55c..c56e05130 100644
--- a/app/logical/media_file/ugoira.rb
+++ b/app/logical/media_file/ugoira.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A MediaFile for a Pixiv ugoira file.
 #
 # A Pixiv ugoira is an animation format that consists of a zip file containing
diff --git a/app/logical/media_file/video.rb b/app/logical/media_file/video.rb
index a24477b03..8a4c8f159 100644
--- a/app/logical/media_file/video.rb
+++ b/app/logical/media_file/video.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A MediaFile for a webm or mp4 video. Uses ffmpeg to generate preview
 # thumbnails.
 #
diff --git a/app/logical/moderator/dashboard/queries/artist.rb b/app/logical/moderator/dashboard/queries/artist.rb
index c9e6f030e..baa949db9 100644
--- a/app/logical/moderator/dashboard/queries/artist.rb
+++ b/app/logical/moderator/dashboard/queries/artist.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/comment.rb b/app/logical/moderator/dashboard/queries/comment.rb
index adf50d17c..c2d7ed463 100644
--- a/app/logical/moderator/dashboard/queries/comment.rb
+++ b/app/logical/moderator/dashboard/queries/comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/mod_action.rb b/app/logical/moderator/dashboard/queries/mod_action.rb
index 9cd2d57dc..0fa619a83 100644
--- a/app/logical/moderator/dashboard/queries/mod_action.rb
+++ b/app/logical/moderator/dashboard/queries/mod_action.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/note.rb b/app/logical/moderator/dashboard/queries/note.rb
index 5979eeaa8..11310819b 100644
--- a/app/logical/moderator/dashboard/queries/note.rb
+++ b/app/logical/moderator/dashboard/queries/note.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/post_appeal.rb b/app/logical/moderator/dashboard/queries/post_appeal.rb
index c0d929f78..de9f08af5 100644
--- a/app/logical/moderator/dashboard/queries/post_appeal.rb
+++ b/app/logical/moderator/dashboard/queries/post_appeal.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/post_flag.rb b/app/logical/moderator/dashboard/queries/post_flag.rb
index 9bc1152e0..09a3ce943 100644
--- a/app/logical/moderator/dashboard/queries/post_flag.rb
+++ b/app/logical/moderator/dashboard/queries/post_flag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/tag.rb b/app/logical/moderator/dashboard/queries/tag.rb
index 82cc2a575..cf69dd45d 100644
--- a/app/logical/moderator/dashboard/queries/tag.rb
+++ b/app/logical/moderator/dashboard/queries/tag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/upload.rb b/app/logical/moderator/dashboard/queries/upload.rb
index 21089c4db..a4c37b8ed 100644
--- a/app/logical/moderator/dashboard/queries/upload.rb
+++ b/app/logical/moderator/dashboard/queries/upload.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/user_feedback.rb b/app/logical/moderator/dashboard/queries/user_feedback.rb
index 81a4a195d..bbacab8ed 100644
--- a/app/logical/moderator/dashboard/queries/user_feedback.rb
+++ b/app/logical/moderator/dashboard/queries/user_feedback.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/queries/wiki_page.rb b/app/logical/moderator/dashboard/queries/wiki_page.rb
index 8af4e0558..76aa984f0 100644
--- a/app/logical/moderator/dashboard/queries/wiki_page.rb
+++ b/app/logical/moderator/dashboard/queries/wiki_page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries
diff --git a/app/logical/moderator/dashboard/report.rb b/app/logical/moderator/dashboard/report.rb
index 972fe665f..4a4d6fb88 100644
--- a/app/logical/moderator/dashboard/report.rb
+++ b/app/logical/moderator/dashboard/report.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     class Report
diff --git a/app/logical/moderator/ip_addr_search.rb b/app/logical/moderator/ip_addr_search.rb
index ac1eb2073..26f3032c6 100644
--- a/app/logical/moderator/ip_addr_search.rb
+++ b/app/logical/moderator/ip_addr_search.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   class IpAddrSearch
     attr_reader :params
diff --git a/app/logical/nico_seiga_api_client.rb b/app/logical/nico_seiga_api_client.rb
index 5979c85fc..f89a4895c 100644
--- a/app/logical/nico_seiga_api_client.rb
+++ b/app/logical/nico_seiga_api_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for the NicoSeiga XML API.
 class NicoSeigaApiClient
   extend Memoist
diff --git a/app/logical/note_sanitizer.rb b/app/logical/note_sanitizer.rb
index 82ee9e12b..ab5b612a9 100644
--- a/app/logical/note_sanitizer.rb
+++ b/app/logical/note_sanitizer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Sanitizes the HTML used in notes. Only safe HTML tags, HTML attributes, and
 # CSS properties are allowed.
 module NoteSanitizer
diff --git a/app/logical/pagination_extension.rb b/app/logical/pagination_extension.rb
index 8a8c83424..ee4722ead 100644
--- a/app/logical/pagination_extension.rb
+++ b/app/logical/pagination_extension.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A mixin that adds a `#paginate` method to an ActiveRecord relation.
 #
 # There are two pagination techniques. The first is page-based (numbered):
diff --git a/app/logical/parameter_builder.rb b/app/logical/parameter_builder.rb
index 2787a5915..0dec3d891 100644
--- a/app/logical/parameter_builder.rb
+++ b/app/logical/parameter_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ParameterBuilder
   def self.serial_parameters(only_string, object)
     only_array = split_only_string(only_string)
diff --git a/app/logical/pixiv_ajax_client.rb b/app/logical/pixiv_ajax_client.rb
index 1dbf5c0af..b6f438c48 100644
--- a/app/logical/pixiv_ajax_client.rb
+++ b/app/logical/pixiv_ajax_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A client for Pixiv's AJAX API.
 #
 # Notes on the API:
diff --git a/app/logical/post_pruner.rb b/app/logical/post_pruner.rb
index d29d1fd99..569910ecd 100644
--- a/app/logical/post_pruner.rb
+++ b/app/logical/post_pruner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Delete posts that were unapproved after three days.
 module PostPruner
   module_function
diff --git a/app/logical/post_query_builder.rb b/app/logical/post_query_builder.rb
index 2e00515ce..ba498a985 100644
--- a/app/logical/post_query_builder.rb
+++ b/app/logical/post_query_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "strscan"
 
 # A PostQueryBuilder represents a post search. It contains all logic for parsing
diff --git a/app/logical/post_search_context.rb b/app/logical/post_search_context.rb
index b0675ff87..2bc7cd90d 100644
--- a/app/logical/post_search_context.rb
+++ b/app/logical/post_search_context.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A PostSearchContext handles navigating to the next or previous post in a
 # search. This is used in the search navbar above or below posts.
 #
diff --git a/app/logical/post_sets/post.rb b/app/logical/post_sets/post.rb
index 72473a68d..dd58d0b29 100644
--- a/app/logical/post_sets/post.rb
+++ b/app/logical/post_sets/post.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A PostSet is a set of posts returned by a search.  This contains helper
 # methods used on the post index page.
 #
diff --git a/app/logical/rate_limiter.rb b/app/logical/rate_limiter.rb
index bde280be3..8693c22c0 100644
--- a/app/logical/rate_limiter.rb
+++ b/app/logical/rate_limiter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A RateLimiter handles HTTP rate limits for controller actions. Rate limits are
 # based on the user, the user's IP, and the controller action.
 #
diff --git a/app/logical/recommender_service.rb b/app/logical/recommender_service.rb
index d2ce85452..564151522 100644
--- a/app/logical/recommender_service.rb
+++ b/app/logical/recommender_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for the post recommendation service. The recommendation service
 # is a separate Python microservice that generates recommended posts for users
 # and posts. This client merely fetches the pre-generated recommendations from
diff --git a/app/logical/related_tag_calculator.rb b/app/logical/related_tag_calculator.rb
index ad5a9d0fd..fff7bd5d3 100644
--- a/app/logical/related_tag_calculator.rb
+++ b/app/logical/related_tag_calculator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Calculate the tags similar to a given tag. Two tags are similar if they have
 # nearly the same set of posts, and nearly the same size.
 #
diff --git a/app/logical/related_tag_query.rb b/app/logical/related_tag_query.rb
index 735179749..a77719682 100644
--- a/app/logical/related_tag_query.rb
+++ b/app/logical/related_tag_query.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Handle finding related tags by the {RelatedTagsController}. Used for finding
 # related tags when tagging a post.
 class RelatedTagQuery
diff --git a/app/logical/reportbooru_service.rb b/app/logical/reportbooru_service.rb
index e1efef532..2c56368bf 100644
--- a/app/logical/reportbooru_service.rb
+++ b/app/logical/reportbooru_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An API client for the Reportbooru service. Reportbooru tracks post view
 # counts, post search counts, and missed search counts.
 #
diff --git a/app/logical/routes.rb b/app/logical/routes.rb
index ab14ce619..a65cd1bd3 100644
--- a/app/logical/routes.rb
+++ b/app/logical/routes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Allow Rails URL helpers to be used outside of views.
 #
 # @example
diff --git a/app/logical/sandbox.rb b/app/logical/sandbox.rb
index 99c9d938d..11166c76c 100644
--- a/app/logical/sandbox.rb
+++ b/app/logical/sandbox.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Run a program inside an isolated sandbox, much like a Docker container. Inside the sandbox,
 # the program doesn't have network access, can't see other programs, and can only see read-only
 # OS directories like /usr and /lib. It can only communicate by reading from stdin and printing
diff --git a/app/logical/seccomp.rb b/app/logical/seccomp.rb
index a141cf1d2..445953b33 100644
--- a/app/logical/seccomp.rb
+++ b/app/logical/seccomp.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This is a wrapper around seccomp, a Linux kernel feature used to limit the
 # system calls the current process is allowed to make. This is used for
 # sandboxing code when processing user-uploaded files.
diff --git a/app/logical/server_status.rb b/app/logical/server_status.rb
index 09a71a487..db22a6617 100644
--- a/app/logical/server_status.rb
+++ b/app/logical/server_status.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Returns status information about the running server, including software
 # versions, basic load info, and Redis and Postgres info.
 #
diff --git a/app/logical/session_loader.rb b/app/logical/session_loader.rb
index 636d6b550..74db0c2c7 100644
--- a/app/logical/session_loader.rb
+++ b/app/logical/session_loader.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Loads the current user from their session cookies or API key. Used by the
 # ApplicationController to set the CurrentUser global early during the HTTP
 # request cycle.
diff --git a/app/logical/set_diff.rb b/app/logical/set_diff.rb
index 3b3c602a2..16c2e5575 100644
--- a/app/logical/set_diff.rb
+++ b/app/logical/set_diff.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Calculate a diff between two sets of strings. Used to calculate diffs between
 # artist URLs and between other names. Tries to compare each set to detect which
 # strings were added, which were removed, and which were changed.
diff --git a/app/logical/sources/error.rb b/app/logical/sources/error.rb
index e88b014fc..79ca185ee 100644
--- a/app/logical/sources/error.rb
+++ b/app/logical/sources/error.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources
   class Error < StandardError
   end
diff --git a/app/logical/sources/strategies.rb b/app/logical/sources/strategies.rb
index a312ad5d5..f2699738e 100644
--- a/app/logical/sources/strategies.rb
+++ b/app/logical/sources/strategies.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources
   module Strategies
     def self.all
diff --git a/app/logical/sources/strategies/art_station.rb b/app/logical/sources/strategies/art_station.rb
index 4703956e7..dc0e7ac54 100644
--- a/app/logical/sources/strategies/art_station.rb
+++ b/app/logical/sources/strategies/art_station.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Page URLs:
 #
 # * https://www.artstation.com/artwork/04XA4
diff --git a/app/logical/sources/strategies/base.rb b/app/logical/sources/strategies/base.rb
index 6fe42e0aa..a060c70b8 100644
--- a/app/logical/sources/strategies/base.rb
+++ b/app/logical/sources/strategies/base.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This is a collection of strategies for extracting information about a
 # resource. At a minimum it tries to extract the artist name and a canonical
 # URL to download the image from. But it can also be used to normalize a URL
diff --git a/app/logical/sources/strategies/deviant_art.rb b/app/logical/sources/strategies/deviant_art.rb
index 900bef666..791a1f527 100644
--- a/app/logical/sources/strategies/deviant_art.rb
+++ b/app/logical/sources/strategies/deviant_art.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Asset URLs:
 #
 ## NORMALIZABLE
diff --git a/app/logical/sources/strategies/fanbox.rb b/app/logical/sources/strategies/fanbox.rb
index 6d5fbf824..1b2c80fd4 100644
--- a/app/logical/sources/strategies/fanbox.rb
+++ b/app/logical/sources/strategies/fanbox.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs #############################################################
 #
 # * OLD DOMAIN
diff --git a/app/logical/sources/strategies/foundation.rb b/app/logical/sources/strategies/foundation.rb
index fe9df3503..9666db76f 100644
--- a/app/logical/sources/strategies/foundation.rb
+++ b/app/logical/sources/strategies/foundation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs
 # * https://f8n-ipfs-production.imgix.net/QmX4MotNAAj9Rcyew43KdgGDxU1QtXemMHoUTNacMLLSjQ/nft.png
 #
diff --git a/app/logical/sources/strategies/hentai_foundry.rb b/app/logical/sources/strategies/hentai_foundry.rb
index 405506f98..8baa11c7b 100644
--- a/app/logical/sources/strategies/hentai_foundry.rb
+++ b/app/logical/sources/strategies/hentai_foundry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs
 #
 # * https://pictures.hentai-foundry.com/a/Afrobull/795025/Afrobull-795025-kuroeda.png
diff --git a/app/logical/sources/strategies/lofter.rb b/app/logical/sources/strategies/lofter.rb
index 0e12b582b..810afdd77 100644
--- a/app/logical/sources/strategies/lofter.rb
+++ b/app/logical/sources/strategies/lofter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs
 #
 # # sample
diff --git a/app/logical/sources/strategies/mastodon.rb b/app/logical/sources/strategies/mastodon.rb
index 714c0dc05..71b683805 100644
--- a/app/logical/sources/strategies/mastodon.rb
+++ b/app/logical/sources/strategies/mastodon.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLS:
 # * https://img.pawoo.net/media_attachments/files/001/297/997/small/c4272a09570757c2.png
 # * https://img.pawoo.net/media_attachments/files/001/297/997/original/c4272a09570757c2.png
diff --git a/app/logical/sources/strategies/moebooru.rb b/app/logical/sources/strategies/moebooru.rb
index 9c94a3a5c..573c20fa4 100644
--- a/app/logical/sources/strategies/moebooru.rb
+++ b/app/logical/sources/strategies/moebooru.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Original images:
 #
 # * https://yande.re/image/b4b1d11facd1700544554e4805d47bb6/.png
diff --git a/app/logical/sources/strategies/newgrounds.rb b/app/logical/sources/strategies/newgrounds.rb
index 5bd00fa7c..d777d30fb 100644
--- a/app/logical/sources/strategies/newgrounds.rb
+++ b/app/logical/sources/strategies/newgrounds.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image Urls
 # * https://art.ngfiles.com/images/1254000/1254722_natthelich_pandora.jpg
 # * https://art.ngfiles.com/images/1033000/1033622_natthelich_fire-emblem-marth-plus-progress-pic.png?f1569487181
diff --git a/app/logical/sources/strategies/nico_seiga.rb b/app/logical/sources/strategies/nico_seiga.rb
index 666f860f1..b19200a4b 100644
--- a/app/logical/sources/strategies/nico_seiga.rb
+++ b/app/logical/sources/strategies/nico_seiga.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Direct URL
 # * https://lohas.nicoseiga.jp/o/971eb8af9bbcde5c2e51d5ef3a2f62d6d9ff5552/1589933964/3583893
 # * http://lohas.nicoseiga.jp/priv/3521156?e=1382558156&h=f2e089256abd1d453a455ec8f317a6c703e2cedf
diff --git a/app/logical/sources/strategies/nijie.rb b/app/logical/sources/strategies/nijie.rb
index d5cfd0b0c..cb554cdb5 100644
--- a/app/logical/sources/strategies/nijie.rb
+++ b/app/logical/sources/strategies/nijie.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs:
 #
 # * https://pic03.nijie.info/nijie_picture/28310_20131101215959.jpg (page: https://www.nijie.info/view.php?id=64240)
diff --git a/app/logical/sources/strategies/null.rb b/app/logical/sources/strategies/null.rb
index 86ff2e530..df5cf1b07 100644
--- a/app/logical/sources/strategies/null.rb
+++ b/app/logical/sources/strategies/null.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources
   module Strategies
     class Null < Base
diff --git a/app/logical/sources/strategies/pixiv.rb b/app/logical/sources/strategies/pixiv.rb
index af7650438..578e15160 100644
--- a/app/logical/sources/strategies/pixiv.rb
+++ b/app/logical/sources/strategies/pixiv.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Pixiv
 #
 # * https://i.pximg.net/img-original/img/2014/10/03/18/10/20/46324488_p0.png
diff --git a/app/logical/sources/strategies/plurk.rb b/app/logical/sources/strategies/plurk.rb
index 8401d8b63..b75e98f59 100644
--- a/app/logical/sources/strategies/plurk.rb
+++ b/app/logical/sources/strategies/plurk.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLs
 #
 # * https://images.plurk.com/5wj6WD0r6y4rLN0DL3sqag.jpg
diff --git a/app/logical/sources/strategies/skeb.rb b/app/logical/sources/strategies/skeb.rb
index 6f12e0209..d8e37aa51 100644
--- a/app/logical/sources/strategies/skeb.rb
+++ b/app/logical/sources/strategies/skeb.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLS
 ## Non-watermarked:
 # * https://skeb.imgix.net/requests/199886_0?bg=%23fff&auto=format&w=800&s=5a6a908ab964fcdfc4713fad179fe715
diff --git a/app/logical/sources/strategies/stash.rb b/app/logical/sources/strategies/stash.rb
index 76b5cf2c7..82c6ec528 100644
--- a/app/logical/sources/strategies/stash.rb
+++ b/app/logical/sources/strategies/stash.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Page URLs:
 # * https://sta.sh/0wxs31o7nn2 (single image)
 # * https://sta.sh/21leo8mz87ue (folder)
diff --git a/app/logical/sources/strategies/tumblr.rb b/app/logical/sources/strategies/tumblr.rb
index 5355f3c64..bf3cde66d 100644
--- a/app/logical/sources/strategies/tumblr.rb
+++ b/app/logical/sources/strategies/tumblr.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # https://marmaladica.tumblr.com/post/188237914346/saved
 # https://66.media.tumblr.com/2c6f55531618b4335c67e29157f5c1fc/tumblr_pz4a44xdVj1ssucdno1_1280.png
 # https://66.media.tumblr.com/11700cab20d65d5a6acc470e284dbd3a/tumblr_pz4a44xdVj1ssucdno2_1280.png
diff --git a/app/logical/sources/strategies/twitter.rb b/app/logical/sources/strategies/twitter.rb
index bc86bd851..ef9ab265b 100644
--- a/app/logical/sources/strategies/twitter.rb
+++ b/app/logical/sources/strategies/twitter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources::Strategies
   class Twitter < Base
     PAGE = %r{\Ahttps?://(?:mobile\.)?twitter\.com}i
diff --git a/app/logical/sources/strategies/weibo.rb b/app/logical/sources/strategies/weibo.rb
index fea8b0f55..7887d7db9 100644
--- a/app/logical/sources/strategies/weibo.rb
+++ b/app/logical/sources/strategies/weibo.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Image URLS
 # * http://ww1.sinaimg.cn/large/69917555gw1f6ggdghk28j20c87lbhdt.jpg
 # * https://wx1.sinaimg.cn/large/002NQ2vhly1gqzqfk1agfj62981aw4qr02.jpg (more than 32 characters in hash)
diff --git a/app/logical/spam_detector.rb b/app/logical/spam_detector.rb
index b327af704..286c5d222 100644
--- a/app/logical/spam_detector.rb
+++ b/app/logical/spam_detector.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Detects whether a dmail, comment, or forum post seems like spam. Autobans
 # users who receive more than 10 spam reports in an hour. Uses the Akismet spam
 # detection service.
diff --git a/app/logical/sqs_service.rb b/app/logical/sqs_service.rb
index 39088a406..4ac6fa6f9 100644
--- a/app/logical/sqs_service.rb
+++ b/app/logical/sqs_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A wrapper for the Amazon SQS API. Used by the PostArchive and PoolArchive
 # service to record post and pool versions.
 #
diff --git a/app/logical/storage_manager.rb b/app/logical/storage_manager.rb
index 8a2a8a4a0..53b314fd0 100644
--- a/app/logical/storage_manager.rb
+++ b/app/logical/storage_manager.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # StorageManager is an abstract superclass that defines a simple interface for
 # storing files on local or remote backends. All image files stored by Danbooru
 # are handled by a StorageManager.
diff --git a/app/logical/storage_manager/local.rb b/app/logical/storage_manager/local.rb
index c79a990b0..0bea843b9 100644
--- a/app/logical/storage_manager/local.rb
+++ b/app/logical/storage_manager/local.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A StorageManager that stores files on the local filesystem.
 class StorageManager::Local < StorageManager
   DEFAULT_PERMISSIONS = 0o644
diff --git a/app/logical/storage_manager/mirror.rb b/app/logical/storage_manager/mirror.rb
index b7dbcc24c..7554a24a3 100644
--- a/app/logical/storage_manager/mirror.rb
+++ b/app/logical/storage_manager/mirror.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A StorageManager that mirrors files across multiple storage backends.
 class StorageManager::Mirror < StorageManager
   attr_reader :services
diff --git a/app/logical/storage_manager/null.rb b/app/logical/storage_manager/null.rb
index 916bf8252..cb887c977 100644
--- a/app/logical/storage_manager/null.rb
+++ b/app/logical/storage_manager/null.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A null StorageManager that doesn't store files at all. Used for testing or
 # disabling backups.
 class StorageManager::Null < StorageManager
diff --git a/app/logical/storage_manager/rclone.rb b/app/logical/storage_manager/rclone.rb
index 715a0f542..de2ffc249 100644
--- a/app/logical/storage_manager/rclone.rb
+++ b/app/logical/storage_manager/rclone.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A StorageManager that stores file on remote filesystem using rclone. Rclone
 # can store files on most cloud storage systems. Requires the `rclone` binary to
 # be installed and configured.
diff --git a/app/logical/table_builder.rb b/app/logical/table_builder.rb
index 6e909fbb0..654c663f6 100644
--- a/app/logical/table_builder.rb
+++ b/app/logical/table_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A helper class for building HTML tables. Used in views.
 #
 # @example
diff --git a/app/logical/tag_category.rb b/app/logical/tag_category.rb
index 0cea52ec9..a484af35a 100644
--- a/app/logical/tag_category.rb
+++ b/app/logical/tag_category.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Utility methods for working with tag categories (general, character,
 # copyright, artist, meta).
 
diff --git a/app/logical/tag_mover.rb b/app/logical/tag_mover.rb
index 624fd508a..9b439b9e3 100644
--- a/app/logical/tag_mover.rb
+++ b/app/logical/tag_mover.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Rename a tag and move everything associated with it. Used when renaming or
 # aliasing a tag in a bulk update request. Moves everything associated with the
 # tag, including aliases, implications, *_(cosplay) and *_(style) tags, artist
diff --git a/app/logical/tag_name_validator.rb b/app/logical/tag_name_validator.rb
index de50d0bdd..08c8a58f5 100644
--- a/app/logical/tag_name_validator.rb
+++ b/app/logical/tag_name_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Define a custom validator for tag names. Tags must be plain ASCII, no spaces,
 # no redundant underscores, no conflicts with metatags, and can't begin with
 # certain special characters.
diff --git a/app/logical/tag_relationship_retirement_service.rb b/app/logical/tag_relationship_retirement_service.rb
index d088ced37..0092acd1a 100644
--- a/app/logical/tag_relationship_retirement_service.rb
+++ b/app/logical/tag_relationship_retirement_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Removes inactive aliases and implications. 'Inactive' means aliases to empty
 # tags, implications from empty tags, and gentag and artist aliases that
 # haven't had any new posts in the last two years.
diff --git a/app/logical/twitter_api_client.rb b/app/logical/twitter_api_client.rb
index c75bcc861..9e52b055f 100644
--- a/app/logical/twitter_api_client.rb
+++ b/app/logical/twitter_api_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A simple Twitter API client that can authenticate to Twitter and fetch tweets by ID.
 # @see https://developer.twitter.com/en/docs/getting-started
 class TwitterApiClient
diff --git a/app/logical/upload_limit.rb b/app/logical/upload_limit.rb
index 845f69e94..639e09c4f 100644
--- a/app/logical/upload_limit.rb
+++ b/app/logical/upload_limit.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Calculates a user's upload limit:
 #
 # * Each status:pending post takes up one upload slot.
diff --git a/app/logical/upload_service.rb b/app/logical/upload_service.rb
index 9e694cd64..84cbabdac 100644
--- a/app/logical/upload_service.rb
+++ b/app/logical/upload_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A service object for uploading an image.
 class UploadService
   attr_reader :params, :post, :upload
diff --git a/app/logical/upload_service/controller_helper.rb b/app/logical/upload_service/controller_helper.rb
index f0c9b70e5..677fe2c6f 100644
--- a/app/logical/upload_service/controller_helper.rb
+++ b/app/logical/upload_service/controller_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadService
   module ControllerHelper
     def self.prepare(url: nil, file: nil, ref: nil)
diff --git a/app/logical/upload_service/preprocessor.rb b/app/logical/upload_service/preprocessor.rb
index c9d397299..c38e31fef 100644
--- a/app/logical/upload_service/preprocessor.rb
+++ b/app/logical/upload_service/preprocessor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadService
   class Preprocessor
     extend Memoist
diff --git a/app/logical/upload_service/replacer.rb b/app/logical/upload_service/replacer.rb
index 20bb3a01c..bd544fa2e 100644
--- a/app/logical/upload_service/replacer.rb
+++ b/app/logical/upload_service/replacer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadService
   class Replacer
     extend Memoist
diff --git a/app/logical/upload_service/utils.rb b/app/logical/upload_service/utils.rb
index 8e57127f5..97ddce849 100644
--- a/app/logical/upload_service/utils.rb
+++ b/app/logical/upload_service/utils.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadService
   module Utils
     module_function
diff --git a/app/logical/user_agent.rb b/app/logical/user_agent.rb
index 4548d3467..db19f450d 100644
--- a/app/logical/user_agent.rb
+++ b/app/logical/user_agent.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Parses a user agent string and tries to determine whether it's a known bot or a known web browser.
 #
 # @see https://developers.whatismybrowser.com/
diff --git a/app/logical/user_deletion.rb b/app/logical/user_deletion.rb
index 2e0779d85..244fd3a06 100644
--- a/app/logical/user_deletion.rb
+++ b/app/logical/user_deletion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Delete a user's account. Deleting an account really just deactivates the
 # account, it doesn't fully delete the user from the database. It wipes their
 # username, password, account settings, favorites, and saved searches, and logs
diff --git a/app/logical/user_name_validator.rb b/app/logical/user_name_validator.rb
index 06e052d88..e55687103 100644
--- a/app/logical/user_name_validator.rb
+++ b/app/logical/user_name_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Define a custom validator for user names.
 #
 # @example
diff --git a/app/logical/user_promotion.rb b/app/logical/user_promotion.rb
index 17f159e02..a80a0c1ee 100644
--- a/app/logical/user_promotion.rb
+++ b/app/logical/user_promotion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Promotes the user to a higher level, or grants them approver or unlimited
 # uploader privileges. Also validates that the promotion is allowed, gives the
 # user a feedback, sends them a notification dmail, and creates a mod action for
diff --git a/app/logical/user_verifier.rb b/app/logical/user_verifier.rb
index f2b26031f..bbfd9abf4 100644
--- a/app/logical/user_verifier.rb
+++ b/app/logical/user_verifier.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Checks whether a new account requires verification. An account requires
 # verification if the IP is a proxy, or the IP is under a partial (signup) IP
 # ban, or it was used to create another account recently.
diff --git a/app/logical/validating_socket.rb b/app/logical/validating_socket.rb
index 8055f924c..f673b745c 100644
--- a/app/logical/validating_socket.rb
+++ b/app/logical/validating_socket.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A TCPSocket wrapper that disallows connections to local or private IPs. Used
 # by {Danbooru::Http} to prevent server-side request forgery (SSRF) attacks. For
 # example, if we try to download an image from http://example.com/image.jpg, but
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
index c5ac3f494..ae19ae2c1 100644
--- a/app/mailers/application_mailer.rb
+++ b/app/mailers/application_mailer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # The base class for emails sent by Danbooru.
 #
 # @see https://guides.rubyonrails.org/action_mailer_basics.html
diff --git a/app/mailers/user_mailer.rb b/app/mailers/user_mailer.rb
index f27be833d..7dec38cab 100644
--- a/app/mailers/user_mailer.rb
+++ b/app/mailers/user_mailer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserMailer < ApplicationMailer
   helper :application
   helper :users
diff --git a/app/models/api_key.rb b/app/models/api_key.rb
index e0296f35a..aab57fffb 100644
--- a/app/models/api_key.rb
+++ b/app/models/api_key.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApiKey < ApplicationRecord
   attribute :permitted_ip_addresses, :ip_address, array: true
   attribute :last_ip_address, :ip_address
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
index dc0296360..ce83135e6 100644
--- a/app/models/application_record.rb
+++ b/app/models/application_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
 
diff --git a/app/models/artist.rb b/app/models/artist.rb
index c5ccc2746..d11cf46d4 100644
--- a/app/models/artist.rb
+++ b/app/models/artist.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Artist < ApplicationRecord
   extend Memoist
   class RevertError < StandardError; end
diff --git a/app/models/artist_commentary.rb b/app/models/artist_commentary.rb
index 551ffb30e..8c4cbfd33 100644
--- a/app/models/artist_commentary.rb
+++ b/app/models/artist_commentary.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistCommentary < ApplicationRecord
   class RevertError < StandardError; end
 
diff --git a/app/models/artist_commentary_version.rb b/app/models/artist_commentary_version.rb
index 93a2e36a7..ec63655b1 100644
--- a/app/models/artist_commentary_version.rb
+++ b/app/models/artist_commentary_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistCommentaryVersion < ApplicationRecord
   belongs_to :post
   belongs_to_updater
diff --git a/app/models/artist_url.rb b/app/models/artist_url.rb
index 6caf2faab..21815f2de 100644
--- a/app/models/artist_url.rb
+++ b/app/models/artist_url.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistUrl < ApplicationRecord
   before_validation :initialize_normalized_url, on: :create
   before_validation :normalize
diff --git a/app/models/artist_version.rb b/app/models/artist_version.rb
index e78395703..58e09a639 100644
--- a/app/models/artist_version.rb
+++ b/app/models/artist_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistVersion < ApplicationRecord
   array_attribute :urls
   array_attribute :other_names
diff --git a/app/models/ban.rb b/app/models/ban.rb
index c3c80bf85..115a9618c 100644
--- a/app/models/ban.rb
+++ b/app/models/ban.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Ban < ApplicationRecord
   attribute :duration, :interval
 
diff --git a/app/models/bulk_update_request.rb b/app/models/bulk_update_request.rb
index 7b3d8e134..35caa9063 100644
--- a/app/models/bulk_update_request.rb
+++ b/app/models/bulk_update_request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BulkUpdateRequest < ApplicationRecord
   STATUSES = %w[pending approved rejected processing failed]
 
diff --git a/app/models/comment.rb b/app/models/comment.rb
index 47237df12..9f2b09a11 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Comment < ApplicationRecord
   belongs_to :post
   belongs_to :creator, class_name: "User"
diff --git a/app/models/comment_vote.rb b/app/models/comment_vote.rb
index 1428a8292..809ff4ffe 100644
--- a/app/models/comment_vote.rb
+++ b/app/models/comment_vote.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentVote < ApplicationRecord
   attr_accessor :updater
 
diff --git a/app/models/dmail.rb b/app/models/dmail.rb
index 0a44e58b6..8fdb661cd 100644
--- a/app/models/dmail.rb
+++ b/app/models/dmail.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Dmail < ApplicationRecord
   validate :validate_sender_is_not_limited, on: :create
   validates :title, presence: true, length: { maximum: 200 }, if: :title_changed?
diff --git a/app/models/dtext_link.rb b/app/models/dtext_link.rb
index 81ef5141a..87af5dcf7 100644
--- a/app/models/dtext_link.rb
+++ b/app/models/dtext_link.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DtextLink < ApplicationRecord
   belongs_to :model, polymorphic: true
   belongs_to :linked_wiki, primary_key: :title, foreign_key: :link_target, class_name: "WikiPage", optional: true
diff --git a/app/models/email_address.rb b/app/models/email_address.rb
index d84033932..0f0b7f39f 100644
--- a/app/models/email_address.rb
+++ b/app/models/email_address.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailAddress < ApplicationRecord
   belongs_to :user, inverse_of: :email_address
 
diff --git a/app/models/favorite.rb b/app/models/favorite.rb
index 732e071cc..0c7a32219 100644
--- a/app/models/favorite.rb
+++ b/app/models/favorite.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Favorite < ApplicationRecord
   belongs_to :post, counter_cache: :fav_count
   belongs_to :user, counter_cache: :favorite_count
diff --git a/app/models/favorite_group.rb b/app/models/favorite_group.rb
index eedde972d..4363f130a 100644
--- a/app/models/favorite_group.rb
+++ b/app/models/favorite_group.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoriteGroup < ApplicationRecord
   belongs_to :creator, class_name: "User"
 
diff --git a/app/models/forum_post.rb b/app/models/forum_post.rb
index fa8872e78..50ca429ad 100644
--- a/app/models/forum_post.rb
+++ b/app/models/forum_post.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPost < ApplicationRecord
   attr_readonly :topic_id
 
diff --git a/app/models/forum_post_vote.rb b/app/models/forum_post_vote.rb
index 87fc0f652..739b1d2cc 100644
--- a/app/models/forum_post_vote.rb
+++ b/app/models/forum_post_vote.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPostVote < ApplicationRecord
   belongs_to :creator, class_name: "User"
   belongs_to :forum_post
diff --git a/app/models/forum_topic.rb b/app/models/forum_topic.rb
index 05de1643d..76056a957 100644
--- a/app/models/forum_topic.rb
+++ b/app/models/forum_topic.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumTopic < ApplicationRecord
   CATEGORIES = {
     0 => "General",
diff --git a/app/models/forum_topic_visit.rb b/app/models/forum_topic_visit.rb
index 2384659b0..06cf8e856 100644
--- a/app/models/forum_topic_visit.rb
+++ b/app/models/forum_topic_visit.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumTopicVisit < ApplicationRecord
   belongs_to :user
   belongs_to :forum_topic
diff --git a/app/models/ip_address.rb b/app/models/ip_address.rb
index e46729406..b25b7345e 100644
--- a/app/models/ip_address.rb
+++ b/app/models/ip_address.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpAddress < ApplicationRecord
   belongs_to :model, polymorphic: true
   belongs_to :user
diff --git a/app/models/ip_ban.rb b/app/models/ip_ban.rb
index c8ee577a2..4091014c4 100644
--- a/app/models/ip_ban.rb
+++ b/app/models/ip_ban.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpBan < ApplicationRecord
   belongs_to :creator, class_name: "User"
 
diff --git a/app/models/ip_geolocation.rb b/app/models/ip_geolocation.rb
index 2712395c1..46f0eb4c9 100644
--- a/app/models/ip_geolocation.rb
+++ b/app/models/ip_geolocation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An IpGeolocation contains metadata associated with an IP address, primarily geolocation data.
 
 class IpGeolocation < ApplicationRecord
diff --git a/app/models/media_asset.rb b/app/models/media_asset.rb
index cb5a11e08..ced1351bc 100644
--- a/app/models/media_asset.rb
+++ b/app/models/media_asset.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MediaAsset < ApplicationRecord
   class Error < StandardError; end
 
diff --git a/app/models/media_metadata.rb b/app/models/media_metadata.rb
index dc7021cf4..23c8d99d0 100644
--- a/app/models/media_metadata.rb
+++ b/app/models/media_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # MediaMetadata represents the EXIF and other metadata associated with a
 # MediaAsset (an uploaded image or video file). The `metadata` field contains a
 # JSON hash of the file's metadata as returned by ExifTool.
diff --git a/app/models/mod_action.rb b/app/models/mod_action.rb
index 2ba3df909..d1090da0b 100644
--- a/app/models/mod_action.rb
+++ b/app/models/mod_action.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModAction < ApplicationRecord
   belongs_to :creator, :class_name => "User"
 
diff --git a/app/models/moderation_report.rb b/app/models/moderation_report.rb
index a5884939b..0e658ec31 100644
--- a/app/models/moderation_report.rb
+++ b/app/models/moderation_report.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModerationReport < ApplicationRecord
   MODEL_TYPES = %w[Dmail Comment ForumPost]
 
diff --git a/app/models/news_update.rb b/app/models/news_update.rb
index f6b3f706a..2bb0b9a5b 100644
--- a/app/models/news_update.rb
+++ b/app/models/news_update.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewsUpdate < ApplicationRecord
   belongs_to :creator, class_name: "User"
   belongs_to_updater
diff --git a/app/models/note.rb b/app/models/note.rb
index 36094f28e..ef4a5e9b7 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Note < ApplicationRecord
   class RevertError < StandardError; end
 
diff --git a/app/models/note_version.rb b/app/models/note_version.rb
index b3c653dc3..94d1366cf 100644
--- a/app/models/note_version.rb
+++ b/app/models/note_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NoteVersion < ApplicationRecord
   belongs_to :post
   belongs_to :note
diff --git a/app/models/pixiv_ugoira_frame_data.rb b/app/models/pixiv_ugoira_frame_data.rb
index 89b7d97b0..e9a872474 100644
--- a/app/models/pixiv_ugoira_frame_data.rb
+++ b/app/models/pixiv_ugoira_frame_data.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PixivUgoiraFrameData < ApplicationRecord
   belongs_to :post, optional: true, foreign_key: :md5, primary_key: :md5
   belongs_to :media_asset, foreign_key: :md5, primary_key: :md5
diff --git a/app/models/pool.rb b/app/models/pool.rb
index f8da79b7c..dc5e61d94 100644
--- a/app/models/pool.rb
+++ b/app/models/pool.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Pool < ApplicationRecord
   class RevertError < StandardError; end
   POOL_ORDER_LIMIT = 1000
diff --git a/app/models/pool_version.rb b/app/models/pool_version.rb
index bf008a429..2ce03400f 100644
--- a/app/models/pool_version.rb
+++ b/app/models/pool_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolVersion < ApplicationRecord
   belongs_to :updater, :class_name => "User"
   belongs_to :pool
diff --git a/app/models/post.rb b/app/models/post.rb
index 4e89dbf9f..5640391bd 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Post < ApplicationRecord
   class RevertError < StandardError; end
   class DeletionError < StandardError; end
diff --git a/app/models/post_appeal.rb b/app/models/post_appeal.rb
index 581ab828b..0939aacb2 100644
--- a/app/models/post_appeal.rb
+++ b/app/models/post_appeal.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostAppeal < ApplicationRecord
   belongs_to :creator, :class_name => "User"
   belongs_to :post
diff --git a/app/models/post_approval.rb b/app/models/post_approval.rb
index 06b5ee7e5..74a847779 100644
--- a/app/models/post_approval.rb
+++ b/app/models/post_approval.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostApproval < ApplicationRecord
   belongs_to :user
   belongs_to :post, inverse_of: :approvals
diff --git a/app/models/post_disapproval.rb b/app/models/post_disapproval.rb
index 8c66a3759..757718895 100644
--- a/app/models/post_disapproval.rb
+++ b/app/models/post_disapproval.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostDisapproval < ApplicationRecord
   DELETION_THRESHOLD = 1.month
   REASONS = %w[breaks_rules poor_quality disinterest]
diff --git a/app/models/post_event.rb b/app/models/post_event.rb
index 09cd5a022..6ae0cd6dc 100644
--- a/app/models/post_event.rb
+++ b/app/models/post_event.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostEvent
   include ActiveModel::Model
   include ActiveModel::Serializers::JSON
diff --git a/app/models/post_flag.rb b/app/models/post_flag.rb
index b151773d1..4ef091839 100644
--- a/app/models/post_flag.rb
+++ b/app/models/post_flag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostFlag < ApplicationRecord
   module Reasons
     UNAPPROVED = "Unapproved in three days"
diff --git a/app/models/post_replacement.rb b/app/models/post_replacement.rb
index 245cdd309..62ed62450 100644
--- a/app/models/post_replacement.rb
+++ b/app/models/post_replacement.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostReplacement < ApplicationRecord
   belongs_to :post
   belongs_to :creator, class_name: "User"
diff --git a/app/models/post_version.rb b/app/models/post_version.rb
index a1a72b574..e6259dad5 100644
--- a/app/models/post_version.rb
+++ b/app/models/post_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVersion < ApplicationRecord
   class RevertError < StandardError; end
   extend Memoist
diff --git a/app/models/post_vote.rb b/app/models/post_vote.rb
index 36e73605f..8ffb3f9f3 100644
--- a/app/models/post_vote.rb
+++ b/app/models/post_vote.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVote < ApplicationRecord
   attr_accessor :updater
 
diff --git a/app/models/rate_limit.rb b/app/models/rate_limit.rb
index 4f6824c8d..6745ce4fd 100644
--- a/app/models/rate_limit.rb
+++ b/app/models/rate_limit.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RateLimit < ApplicationRecord
   scope :expired, -> { where("updated_at < ?", 1.hour.ago) }
 
diff --git a/app/models/saved_search.rb b/app/models/saved_search.rb
index 6af795447..501ae8173 100644
--- a/app/models/saved_search.rb
+++ b/app/models/saved_search.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SavedSearch < ApplicationRecord
   REDIS_EXPIRY = 1.hour
   QUERY_LIMIT = 1000
diff --git a/app/models/tag.rb b/app/models/tag.rb
index 9ccfa309c..dae7bfae7 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tag < ApplicationRecord
   ABBREVIATION_REGEXP = /([a-z0-9])[a-z0-9']*($|[^a-z0-9']+)/
 
diff --git a/app/models/tag_alias.rb b/app/models/tag_alias.rb
index 5b76473bb..3019a433c 100644
--- a/app/models/tag_alias.rb
+++ b/app/models/tag_alias.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagAlias < TagRelationship
   # Validate that the alias doesn't exist yet when it's created or when a BUR
   # is requested, but not when a BUR is approved (to allow failed BURs to be reapproved)
diff --git a/app/models/tag_implication.rb b/app/models/tag_implication.rb
index d8892cd2b..28c2feb9a 100644
--- a/app/models/tag_implication.rb
+++ b/app/models/tag_implication.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagImplication < TagRelationship
   MINIMUM_TAG_COUNT = 10
   MINIMUM_TAG_PERCENTAGE = 0.0001
diff --git a/app/models/tag_relationship.rb b/app/models/tag_relationship.rb
index f1124cae3..d1114de31 100644
--- a/app/models/tag_relationship.rb
+++ b/app/models/tag_relationship.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagRelationship < ApplicationRecord
   STATUSES = %w[active deleted retired]
 
diff --git a/app/models/upload.rb b/app/models/upload.rb
index 069d2949d..ae7b22c29 100644
--- a/app/models/upload.rb
+++ b/app/models/upload.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Upload < ApplicationRecord
   class Error < StandardError; end
 
diff --git a/app/models/user.rb b/app/models/user.rb
index 74b21d966..27f80d6c6 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class User < ApplicationRecord
   class PrivilegeError < StandardError; end
 
diff --git a/app/models/user_event.rb b/app/models/user_event.rb
index 3894251f9..12dc03f1b 100644
--- a/app/models/user_event.rb
+++ b/app/models/user_event.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A UserEvent is used to track important events related to a user's account,
 # such as signups, logins, password changes, etc. A UserEvent is associated
 # with a UserSession, which contains the IP and browser information associated
diff --git a/app/models/user_feedback.rb b/app/models/user_feedback.rb
index 809d37dc5..fef58502d 100644
--- a/app/models/user_feedback.rb
+++ b/app/models/user_feedback.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserFeedback < ApplicationRecord
   self.table_name = "user_feedback"
 
diff --git a/app/models/user_name_change_request.rb b/app/models/user_name_change_request.rb
index d87b457e6..a26935947 100644
--- a/app/models/user_name_change_request.rb
+++ b/app/models/user_name_change_request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserNameChangeRequest < ApplicationRecord
   belongs_to :user
   belongs_to :approver, class_name: "User", optional: true
diff --git a/app/models/user_session.rb b/app/models/user_session.rb
index 7044426b3..ee5adaff7 100644
--- a/app/models/user_session.rb
+++ b/app/models/user_session.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A UserSession contains browser and IP metadata associated with a UserEvent. This
 # includes the user's session ID from their session cookie, their IP address,
 # and their browser user agent. This is used to track logins and other events.
diff --git a/app/models/user_upgrade.rb b/app/models/user_upgrade.rb
index 4857fbeda..46dee3845 100644
--- a/app/models/user_upgrade.rb
+++ b/app/models/user_upgrade.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserUpgrade < ApplicationRecord
   belongs_to :recipient, class_name: "User"
   belongs_to :purchaser, class_name: "User"
diff --git a/app/models/wiki_page.rb b/app/models/wiki_page.rb
index ab7906a0c..d8e7fe620 100644
--- a/app/models/wiki_page.rb
+++ b/app/models/wiki_page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WikiPage < ApplicationRecord
   class RevertError < StandardError; end
 
diff --git a/app/models/wiki_page_version.rb b/app/models/wiki_page_version.rb
index 962441097..64d9ca5f5 100644
--- a/app/models/wiki_page_version.rb
+++ b/app/models/wiki_page_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WikiPageVersion < ApplicationRecord
   array_attribute :other_names
   belongs_to :wiki_page
diff --git a/app/policies/api_key_policy.rb b/app/policies/api_key_policy.rb
index 44e9178f6..b422ee2b3 100644
--- a/app/policies/api_key_policy.rb
+++ b/app/policies/api_key_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApiKeyPolicy < ApplicationPolicy
   def new?
     !user.is_anonymous?
diff --git a/app/policies/application_policy.rb b/app/policies/application_policy.rb
index 6775f45ab..81bbb2797 100644
--- a/app/policies/application_policy.rb
+++ b/app/policies/application_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationPolicy
   attr_reader :user, :record
 
diff --git a/app/policies/artist_commentary_policy.rb b/app/policies/artist_commentary_policy.rb
index 2a88a9311..c59b0eec6 100644
--- a/app/policies/artist_commentary_policy.rb
+++ b/app/policies/artist_commentary_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistCommentaryPolicy < ApplicationPolicy
   def create_or_update?
     unbanned?
diff --git a/app/policies/artist_policy.rb b/app/policies/artist_policy.rb
index cd9f4b914..a0519cc2b 100644
--- a/app/policies/artist_policy.rb
+++ b/app/policies/artist_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistPolicy < ApplicationPolicy
   def ban?
     user.is_admin? && !record.is_banned?
diff --git a/app/policies/artist_version_policy.rb b/app/policies/artist_version_policy.rb
index 347e5689e..4322f10a7 100644
--- a/app/policies/artist_version_policy.rb
+++ b/app/policies/artist_version_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArtistVersionPolicy < ApplicationPolicy
   def can_view_banned?
     policy(Artist).can_view_banned?
diff --git a/app/policies/ban_policy.rb b/app/policies/ban_policy.rb
index 554e82c5b..60c2f8765 100644
--- a/app/policies/ban_policy.rb
+++ b/app/policies/ban_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BanPolicy < ApplicationPolicy
   def bannable?
     user.is_moderator? && (record.user.blank? || (record.user.level < user.level))
diff --git a/app/policies/bulk_update_request_policy.rb b/app/policies/bulk_update_request_policy.rb
index 83c91d947..c8246987a 100644
--- a/app/policies/bulk_update_request_policy.rb
+++ b/app/policies/bulk_update_request_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BulkUpdateRequestPolicy < ApplicationPolicy
   def create?
     unbanned? && (record.forum_topic.blank? || policy(record.forum_topic).reply?)
diff --git a/app/policies/comment_policy.rb b/app/policies/comment_policy.rb
index b832ee294..1acbd6b15 100644
--- a/app/policies/comment_policy.rb
+++ b/app/policies/comment_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentPolicy < ApplicationPolicy
   def create?
     unbanned?
diff --git a/app/policies/comment_vote_policy.rb b/app/policies/comment_vote_policy.rb
index a2389fd1c..d3ce8fe7b 100644
--- a/app/policies/comment_vote_policy.rb
+++ b/app/policies/comment_vote_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentVotePolicy < ApplicationPolicy
   def create?
     unbanned? && !record.comment.is_deleted?
diff --git a/app/policies/delayed_job_policy.rb b/app/policies/delayed_job_policy.rb
index a064c3c54..bcfdd6e0b 100644
--- a/app/policies/delayed_job_policy.rb
+++ b/app/policies/delayed_job_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DelayedJobPolicy < ApplicationPolicy
   def update?
     user.is_admin?
diff --git a/app/policies/dmail_policy.rb b/app/policies/dmail_policy.rb
index 29585b438..0cc6121a9 100644
--- a/app/policies/dmail_policy.rb
+++ b/app/policies/dmail_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DmailPolicy < ApplicationPolicy
   def create?
     unbanned?
diff --git a/app/policies/email_address_policy.rb b/app/policies/email_address_policy.rb
index 2f8ee8da2..114d7ecea 100644
--- a/app/policies/email_address_policy.rb
+++ b/app/policies/email_address_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailAddressPolicy < ApplicationPolicy
   def index?
     user.is_moderator?
diff --git a/app/policies/favorite_group_policy.rb b/app/policies/favorite_group_policy.rb
index 8926a1f8b..b201ab70a 100644
--- a/app/policies/favorite_group_policy.rb
+++ b/app/policies/favorite_group_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoriteGroupPolicy < ApplicationPolicy
   def show?
     record.creator_id == user.id || record.is_public
diff --git a/app/policies/favorite_policy.rb b/app/policies/favorite_policy.rb
index 4c3a5aef2..ae3c09560 100644
--- a/app/policies/favorite_policy.rb
+++ b/app/policies/favorite_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FavoritePolicy < ApplicationPolicy
   def create?
     unbanned? && user.is_member?
diff --git a/app/policies/forum_post_policy.rb b/app/policies/forum_post_policy.rb
index 30952650e..355877613 100644
--- a/app/policies/forum_post_policy.rb
+++ b/app/policies/forum_post_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPostPolicy < ApplicationPolicy
   def index?
     true
diff --git a/app/policies/forum_post_vote_policy.rb b/app/policies/forum_post_vote_policy.rb
index f5b83030e..7d5621c86 100644
--- a/app/policies/forum_post_vote_policy.rb
+++ b/app/policies/forum_post_vote_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumPostVotePolicy < ApplicationPolicy
   def create?
     unbanned? && policy(record.forum_post).votable?
diff --git a/app/policies/forum_topic_policy.rb b/app/policies/forum_topic_policy.rb
index 849b6e86d..82539b7c0 100644
--- a/app/policies/forum_topic_policy.rb
+++ b/app/policies/forum_topic_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ForumTopicPolicy < ApplicationPolicy
   def index?
     true
diff --git a/app/policies/ip_address_policy.rb b/app/policies/ip_address_policy.rb
index 209ccb541..279875ddd 100644
--- a/app/policies/ip_address_policy.rb
+++ b/app/policies/ip_address_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpAddressPolicy < ApplicationPolicy
   def index?
     user.is_moderator?
diff --git a/app/policies/ip_ban_policy.rb b/app/policies/ip_ban_policy.rb
index c10665b50..c1d7d4538 100644
--- a/app/policies/ip_ban_policy.rb
+++ b/app/policies/ip_ban_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpBanPolicy < ApplicationPolicy
   def create?
     user.is_moderator?
diff --git a/app/policies/ip_geolocation_policy.rb b/app/policies/ip_geolocation_policy.rb
index bd269f3ee..0a0a7492d 100644
--- a/app/policies/ip_geolocation_policy.rb
+++ b/app/policies/ip_geolocation_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IpGeolocationPolicy < ApplicationPolicy
   def index?
     user.is_moderator?
diff --git a/app/policies/media_asset_policy.rb b/app/policies/media_asset_policy.rb
index ebef2da96..636cd1431 100644
--- a/app/policies/media_asset_policy.rb
+++ b/app/policies/media_asset_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MediaAssetPolicy < ApplicationPolicy
   def index?
     true
diff --git a/app/policies/media_metadata_policy.rb b/app/policies/media_metadata_policy.rb
index fe0039160..4b10943ee 100644
--- a/app/policies/media_metadata_policy.rb
+++ b/app/policies/media_metadata_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MediaMetadataPolicy < ApplicationPolicy
   def index?
     true
diff --git a/app/policies/mod_action_policy.rb b/app/policies/mod_action_policy.rb
index 8972a4bae..730794f65 100644
--- a/app/policies/mod_action_policy.rb
+++ b/app/policies/mod_action_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModActionPolicy < ApplicationPolicy
   def api_attributes
     super + [:category_id]
diff --git a/app/policies/moderation_report_policy.rb b/app/policies/moderation_report_policy.rb
index 2b1430a6b..be2d041ef 100644
--- a/app/policies/moderation_report_policy.rb
+++ b/app/policies/moderation_report_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModerationReportPolicy < ApplicationPolicy
   def index?
     !user.is_anonymous?
diff --git a/app/policies/modqueue_policy.rb b/app/policies/modqueue_policy.rb
index 22ab3b828..7501f0388 100644
--- a/app/policies/modqueue_policy.rb
+++ b/app/policies/modqueue_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ModqueuePolicy < ApplicationPolicy
   def index?
     user.is_approver?
diff --git a/app/policies/news_update_policy.rb b/app/policies/news_update_policy.rb
index de059be33..888d8c16d 100644
--- a/app/policies/news_update_policy.rb
+++ b/app/policies/news_update_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewsUpdatePolicy < ApplicationPolicy
   def index?
     user.is_admin?
diff --git a/app/policies/nil_class_policy.rb b/app/policies/nil_class_policy.rb
index 8bce8769e..a307b1f66 100644
--- a/app/policies/nil_class_policy.rb
+++ b/app/policies/nil_class_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NilClassPolicy < ApplicationPolicy
   def index?
     false
diff --git a/app/policies/note_policy.rb b/app/policies/note_policy.rb
index 24921c54e..bcf99eab9 100644
--- a/app/policies/note_policy.rb
+++ b/app/policies/note_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NotePolicy < ApplicationPolicy
   def revert?
     update?
diff --git a/app/policies/password_policy.rb b/app/policies/password_policy.rb
index 3c34af574..67257d6af 100644
--- a/app/policies/password_policy.rb
+++ b/app/policies/password_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PasswordPolicy < ApplicationPolicy
   def update?
     record.id == user.id || user.is_owner?
diff --git a/app/policies/pool_policy.rb b/app/policies/pool_policy.rb
index 7cf10061d..34c1c5783 100644
--- a/app/policies/pool_policy.rb
+++ b/app/policies/pool_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PoolPolicy < ApplicationPolicy
   def gallery?
     index?
diff --git a/app/policies/post_appeal_policy.rb b/app/policies/post_appeal_policy.rb
index fa18feaf1..c59082472 100644
--- a/app/policies/post_appeal_policy.rb
+++ b/app/policies/post_appeal_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostAppealPolicy < ApplicationPolicy
   def edit?
     update?
diff --git a/app/policies/post_approval_policy.rb b/app/policies/post_approval_policy.rb
index de762f9d1..bb39f3b4e 100644
--- a/app/policies/post_approval_policy.rb
+++ b/app/policies/post_approval_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostApprovalPolicy < ApplicationPolicy
   def create?
     user.is_approver?
diff --git a/app/policies/post_disapproval_policy.rb b/app/policies/post_disapproval_policy.rb
index cf2416ebe..49fa56916 100644
--- a/app/policies/post_disapproval_policy.rb
+++ b/app/policies/post_disapproval_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostDisapprovalPolicy < ApplicationPolicy
   def create?
     user.is_approver?
diff --git a/app/policies/post_flag_policy.rb b/app/policies/post_flag_policy.rb
index 937439bbc..50daea170 100644
--- a/app/policies/post_flag_policy.rb
+++ b/app/policies/post_flag_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostFlagPolicy < ApplicationPolicy
   def edit?
     update?
diff --git a/app/policies/post_policy.rb b/app/policies/post_policy.rb
index ae2592e42..9141e993f 100644
--- a/app/policies/post_policy.rb
+++ b/app/policies/post_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostPolicy < ApplicationPolicy
   def show_seq?
     true
diff --git a/app/policies/post_replacement_policy.rb b/app/policies/post_replacement_policy.rb
index 302bff637..f5ad74e8a 100644
--- a/app/policies/post_replacement_policy.rb
+++ b/app/policies/post_replacement_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostReplacementPolicy < ApplicationPolicy
   def create?
     user.is_moderator?
diff --git a/app/policies/post_version_policy.rb b/app/policies/post_version_policy.rb
index 199cf100b..5c7f414ec 100644
--- a/app/policies/post_version_policy.rb
+++ b/app/policies/post_version_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVersionPolicy < ApplicationPolicy
   def undo?
     unbanned? && record.version > 1 && record.post.present? && policy(record.post).visible?
diff --git a/app/policies/post_vote_policy.rb b/app/policies/post_vote_policy.rb
index 4a89d6b8f..ce7cd84ee 100644
--- a/app/policies/post_vote_policy.rb
+++ b/app/policies/post_vote_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostVotePolicy < ApplicationPolicy
   def create?
     unbanned? && user.is_member?
diff --git a/app/policies/rate_limit_policy.rb b/app/policies/rate_limit_policy.rb
index 9970ac553..67132edd4 100644
--- a/app/policies/rate_limit_policy.rb
+++ b/app/policies/rate_limit_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RateLimitPolicy < ApplicationPolicy
   def index?
     true
diff --git a/app/policies/saved_search_policy.rb b/app/policies/saved_search_policy.rb
index d43298575..b3d1ea48a 100644
--- a/app/policies/saved_search_policy.rb
+++ b/app/policies/saved_search_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SavedSearchPolicy < ApplicationPolicy
   def index?
     !user.is_anonymous?
diff --git a/app/policies/tag_alias_policy.rb b/app/policies/tag_alias_policy.rb
index 15ed6acb3..f03831723 100644
--- a/app/policies/tag_alias_policy.rb
+++ b/app/policies/tag_alias_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagAliasPolicy < ApplicationPolicy
   def destroy?
     user.is_admin?
diff --git a/app/policies/tag_implication_policy.rb b/app/policies/tag_implication_policy.rb
index e46a89fce..b3a4b15aa 100644
--- a/app/policies/tag_implication_policy.rb
+++ b/app/policies/tag_implication_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagImplicationPolicy < ApplicationPolicy
   def destroy?
     user.is_admin?
diff --git a/app/policies/tag_policy.rb b/app/policies/tag_policy.rb
index 88a48c10a..563279321 100644
--- a/app/policies/tag_policy.rb
+++ b/app/policies/tag_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TagPolicy < ApplicationPolicy
   def can_change_category?
     user.is_admin? ||
diff --git a/app/policies/upload_policy.rb b/app/policies/upload_policy.rb
index a5c7f7211..e0c065647 100644
--- a/app/policies/upload_policy.rb
+++ b/app/policies/upload_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadPolicy < ApplicationPolicy
   def show?
     record.is_completed? || user.is_admin? || record.uploader_id == user.id
diff --git a/app/policies/user_event_policy.rb b/app/policies/user_event_policy.rb
index ddc8b240e..7d508318c 100644
--- a/app/policies/user_event_policy.rb
+++ b/app/policies/user_event_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserEventPolicy < ApplicationPolicy
   def index?
     user.is_moderator?
diff --git a/app/policies/user_feedback_policy.rb b/app/policies/user_feedback_policy.rb
index 64c1d34f8..4c07fb414 100644
--- a/app/policies/user_feedback_policy.rb
+++ b/app/policies/user_feedback_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserFeedbackPolicy < ApplicationPolicy
   def create?
     unbanned? && user.is_gold? && record.user_id != user.id
diff --git a/app/policies/user_name_change_request_policy.rb b/app/policies/user_name_change_request_policy.rb
index e278018c4..1d3782a36 100644
--- a/app/policies/user_name_change_request_policy.rb
+++ b/app/policies/user_name_change_request_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserNameChangeRequestPolicy < ApplicationPolicy
   def index?
     !user.is_anonymous?
diff --git a/app/policies/user_policy.rb b/app/policies/user_policy.rb
index 75ae4deb5..4e68aa840 100644
--- a/app/policies/user_policy.rb
+++ b/app/policies/user_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserPolicy < ApplicationPolicy
   def create?
     true
diff --git a/app/policies/user_session_policy.rb b/app/policies/user_session_policy.rb
index db6a26d38..8e627e001 100644
--- a/app/policies/user_session_policy.rb
+++ b/app/policies/user_session_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserSessionPolicy < ApplicationPolicy
   def index?
     user.is_admin?
diff --git a/app/policies/user_upgrade_policy.rb b/app/policies/user_upgrade_policy.rb
index a81e80c50..641af6045 100644
--- a/app/policies/user_upgrade_policy.rb
+++ b/app/policies/user_upgrade_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserUpgradePolicy < ApplicationPolicy
   def create?
     !user.is_anonymous?
diff --git a/app/policies/wiki_page_policy.rb b/app/policies/wiki_page_policy.rb
index 81b897fcc..919406d6a 100644
--- a/app/policies/wiki_page_policy.rb
+++ b/app/policies/wiki_page_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WikiPagePolicy < ApplicationPolicy
   def update?
     unbanned? && (can_edit_locked? || !record.is_locked?)
diff --git a/app/presenters/post_presenter.rb b/app/presenters/post_presenter.rb
index a2f6c3667..53b22c727 100644
--- a/app/presenters/post_presenter.rb
+++ b/app/presenters/post_presenter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostPresenter
   attr_reader :pool, :next_post_in_pool
 
diff --git a/app/presenters/tag_set_presenter.rb b/app/presenters/tag_set_presenter.rb
index 86df658a5..e893b8f90 100644
--- a/app/presenters/tag_set_presenter.rb
+++ b/app/presenters/tag_set_presenter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # rdoc
 #   A tag set represents a set of tags that are displayed together.
 #   This class makes it easy to fetch the categories for all the
diff --git a/app/presenters/user_presenter.rb b/app/presenters/user_presenter.rb
index a7e30acba..52e7f5539 100644
--- a/app/presenters/user_presenter.rb
+++ b/app/presenters/user_presenter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserPresenter
   attr_reader :user