Inherit errors from StandardError instead of Exception.

app/models/artist.rb

@@ -1,6 +1,6 @@
 class Artist < ApplicationRecord
   extend Memoist
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
 
   attr_accessor :url_string_changed
   array_attribute :other_names

app/models/artist_commentary.rb

@@ -1,5 +1,5 @@
 class ArtistCommentary < ApplicationRecord
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
 
   attr_accessor :remove_commentary_tag, :remove_commentary_request_tag, :remove_commentary_check_tag, :remove_partial_commentary_tag
   attr_accessor :add_commentary_tag, :add_commentary_request_tag, :add_commentary_check_tag, :add_partial_commentary_tag

app/models/comment_vote.rb

@@ -1,5 +1,5 @@
 class CommentVote < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   belongs_to :comment
   belongs_to :user

app/models/favorite.rb

@@ -1,5 +1,5 @@
 class Favorite < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   belongs_to :post
   belongs_to :user

app/models/note.rb

@@ -1,5 +1,5 @@
 class Note < ApplicationRecord
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
 
   attr_accessor :html_id
   belongs_to :post

app/models/pool.rb

@@ -1,5 +1,5 @@
 class Pool < ApplicationRecord
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
   POOL_ORDER_LIMIT = 1000
 
   array_attribute :post_ids, parse: /\d+/, cast: :to_i

app/models/pool_version.rb

@@ -1,5 +1,5 @@
 class PoolVersion < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   belongs_to :pool
   belongs_to_updater

app/models/post.rb

@@ -1,12 +1,12 @@
 require 'danbooru/has_bit_flags'
 
 class Post < ApplicationRecord
-  class ApprovalError < Exception; end
-  class DisapprovalError < Exception; end
-  class RevertError < Exception; end
-  class SearchError < Exception; end
-  class DeletionError < Exception; end
-  class TimeoutError < Exception; end
+  class ApprovalError < StandardError; end
+  class DisapprovalError < StandardError; end
+  class RevertError < StandardError; end
+  class SearchError < StandardError; end
+  class DeletionError < StandardError; end
+  class TimeoutError < StandardError; end
 
   # Tags to copy when copying notes.
   NOTE_COPY_TAGS = %w[translated partially_translated check_translation translation_request reverse_translation]

app/models/post_appeal.rb

@@ -1,5 +1,5 @@
 class PostAppeal < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   MAX_APPEALS_PER_DAY = 1
 

app/models/post_archive.rb

@@ -1,5 +1,5 @@
 class PostArchive < ApplicationRecord
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
   extend Memoist
 
   belongs_to :post

app/models/post_flag.rb

@@ -1,5 +1,5 @@
 class PostFlag < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   module Reasons
     UNAPPROVED = "Unapproved in three days"

app/models/post_vote.rb

@@ -1,5 +1,5 @@
 class PostVote < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   belongs_to :post
   belongs_to :user

app/models/upload.rb

@@ -1,7 +1,7 @@
 require "tmpdir"
 
 class Upload < ApplicationRecord
-  class Error < Exception; end
+  class Error < StandardError; end
 
   class FileValidator < ActiveModel::Validator
     def validate(record)

app/models/user.rb

@@ -2,8 +2,8 @@ require 'digest/sha1'
 require 'danbooru/has_bit_flags'
 
 class User < ApplicationRecord
-  class Error < Exception; end
-  class PrivilegeError < Exception; end
+  class Error < StandardError; end
+  class PrivilegeError < StandardError; end
 
   module Levels
     ANONYMOUS = 0

app/models/wiki_page.rb

@@ -1,5 +1,5 @@
 class WikiPage < ApplicationRecord
-  class RevertError < Exception; end
+  class RevertError < StandardError; end
 
   META_WIKIS = ["list_of_", "tag_group:", "pool_group:", "howto:", "about:", "help:", "template:"]