Enable frozen string literals.

Make all string literals immutable by default.

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.
 #

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

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

app/logical/autocomplete_service.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Autocomplete tags, usernames, pools, and more.
 #
 # @example

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.
 #

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

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

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.
 #

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

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

app/logical/concerns/array_attribute.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ArrayAttribute
   extend ActiveSupport::Concern
 

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

app/logical/concerns/has_bit_flags.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module HasBitFlags
   extend ActiveSupport::Concern
 

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.

app/logical/concerns/normalizable.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Normalizable
   extend ActiveSupport::Concern
 

app/logical/concerns/searchable.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Searchable
   extend ActiveSupport::Concern
 

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.

app/logical/d_text.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'cgi'
 require 'uri'
 

app/logical/danbooru/helpers.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   module Helpers
     module_function

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"

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

app/logical/danbooru/http/cache.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Cache < HTTP::Feature

app/logical/danbooru/http/html_adapter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class HtmlAdapter < HTTP::MimeType::Adapter

app/logical/danbooru/http/logger.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Logger < HTTP::Feature

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

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.
 #

app/logical/danbooru/http/session.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class Session < HTTP::Feature

app/logical/danbooru/http/spoof_referrer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class SpoofReferrer < HTTP::Feature

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.
 #

app/logical/danbooru/http/xml_adapter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class Http
     class XmlAdapter < HTTP::MimeType::Adapter

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

app/logical/danbooru/message_verifier.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Danbooru
   class MessageVerifier
     attr_reader :purpose, :secret, :verifier

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

app/logical/danbooru_maintenance.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DanbooruMaintenance
   module_function
 

app/logical/deep_danbooru_client.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeepDanbooruClient
   attr_reader :http
 

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

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

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

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

app/logical/discord_slash_command/count_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class CountCommand < DiscordSlashCommand
     self.name = "count"

app/logical/discord_slash_command/post_embed.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostEmbed
     attr_reader :post, :command

app/logical/discord_slash_command/posts_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class PostsCommand < DiscordSlashCommand
     extend Memoist

app/logical/discord_slash_command/random_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class RandomCommand < DiscordSlashCommand
     self.name = "random"

app/logical/discord_slash_command/tagme_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TagmeCommand < DiscordSlashCommand
     self.name = "tagme"

app/logical/discord_slash_command/time_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class TimeCommand < DiscordSlashCommand
     self.name = "time"

app/logical/discord_slash_command/wiki_command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DiscordSlashCommand
   class WikiCommand < DiscordSlashCommand
     extend Memoist

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
 

app/logical/dtext_input.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # A custom SimpleForm input for DText fields.
 #
 # Usage:

app/logical/duration_parser.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'abbrev'
 
 module DurationParser

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

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,

app/logical/ffmpeg.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "shellwords"
 
 # A wrapper for the ffmpeg command.

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

app/logical/image_proxy.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ImageProxy
   class Error < StandardError; end
 

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"

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.
 #

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.
 #

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

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.

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
 #

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

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

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.
 #

app/logical/moderator/dashboard/queries/artist.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/comment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/mod_action.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/note.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/post_appeal.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/post_flag.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/tag.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/upload.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/user_feedback.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/queries/wiki_page.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     module Queries

app/logical/moderator/dashboard/report.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   module Dashboard
     class Report

app/logical/moderator/ip_addr_search.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moderator
   class IpAddrSearch
     attr_reader :params

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

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

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):

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)

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:

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

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

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.
 #

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.
 #

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.
 #

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

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.
 #

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

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.
 #

app/logical/routes.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Allow Rails URL helpers to be used outside of views.
 #
 # @example

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

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.

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.
 #

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.

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.

app/logical/sources/error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources
   class Error < StandardError
   end

app/logical/sources/strategies.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sources
   module Strategies
     def self.all

app/logical/sources/strategies/art_station.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Page URLs:
 #
 # * https://www.artstation.com/artwork/04XA4

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

app/logical/sources/strategies/deviant_art.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Asset URLs:
 #
 ## NORMALIZABLE