Correct validators so that existing error messages would look correct (#3668)

app/models/account.rb

@@ -57,7 +57,8 @@ class Account < ApplicationRecord
   validates :username, uniqueness: { scope: :domain, case_sensitive: true }, if: -> { !local? && username_changed? }
 
   # Local user validations
-  validates :username, format: { with: /\A[a-z0-9_]+\z/i }, uniqueness: { scope: :domain, case_sensitive: false }, length: { maximum: 30 }, unreserved: true, if: -> { local? && username_changed? }
+  validates :username, format: { with: /\A[a-z0-9_]+\z/i }, uniqueness: { scope: :domain, case_sensitive: false }, length: { maximum: 30 }, if: -> { local? && username_changed? }
+  validates_with UnreservedUsernameValidator, if: -> { local? && username_changed? }
   validates :display_name, length: { maximum: 30 }, if: -> { local? && display_name_changed? }
   validates :note, length: { maximum: 160 }, if: -> { local? && note_changed? }
 

app/models/user.rb

@@ -47,7 +47,7 @@ class User < ApplicationRecord
   accepts_nested_attributes_for :account
 
   validates :locale, inclusion: I18n.available_locales.map(&:to_s), if: :locale?
-  validates :email, email: true, if: :email_changed?
+  validates_with BlacklistedEmailValidator, if: :email_changed?
 
   scope :recent,    -> { order(id: :desc) }
   scope :admins,    -> { where(admin: true) }

app/validators/blacklisted_email_validator.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-class EmailValidator < ActiveModel::EachValidator
-  def validate_each(record, attribute, value)
-    record.errors.add(attribute, I18n.t('users.invalid_email')) if blocked_email?(value)
+class BlacklistedEmailValidator < ActiveModel::Validator
+  def validate(user)
+    user.errors.add(:email, I18n.t('users.invalid_email')) if blocked_email?(user.email)
   end
 
   private

app/validators/unreserved_username_validator.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class UnreservedUsernameValidator < ActiveModel::Validator
+  def validate(account)
+    return if account.username.nil?
+    account.errors.add(:username, I18n.t('accounts.reserved_username')) if reserved_username?(account.username)
+  end
+
+  private
+
+  def reserved_username?(value)
+    return false unless Setting.reserved_usernames
+    Setting.reserved_usernames.include?(value.downcase)
+  end
+end

app/validators/unreserved_validator.rb

@@ -1,15 +0,0 @@
-# frozen_string_literal: true
-
-class UnreservedValidator < ActiveModel::EachValidator
-  def validate_each(record, attribute, value)
-    return if value.nil?
-    record.errors.add(attribute, I18n.t('accounts.reserved_username')) if reserved_username?(value)
-  end
-
-  private
-
-  def reserved_username?(value)
-    return false unless Setting.reserved_usernames
-    Setting.reserved_usernames.include?(value.downcase)
-  end
-end