Fix crash when saving invalid domain name (mastodon#11528)

Fix mastodon#7629

Author: Gargron

app/models/account_domain_block.rb

@@ -15,7 +15,7 @@ class AccountDomainBlock < ApplicationRecord
   include DomainNormalizable
 
   belongs_to :account
-  validates :domain, presence: true, uniqueness: { scope: :account_id }
+  validates :domain, presence: true, uniqueness: { scope: :account_id }, domain: true
 
   after_commit :remove_blocking_cache
   after_commit :remove_relationship_cache

app/models/concerns/domain_normalizable.rb

@@ -4,7 +4,7 @@ module DomainNormalizable
   extend ActiveSupport::Concern
 
   included do
-    before_validation :normalize_domain
+    before_save :normalize_domain
   end
 
   private

app/models/domain_allow.rb

@@ -13,7 +13,7 @@
 class DomainAllow < ApplicationRecord
   include DomainNormalizable
 
-  validates :domain, presence: true, uniqueness: true
+  validates :domain, presence: true, uniqueness: true, domain: true
 
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
 

app/models/domain_block.rb

@@ -19,7 +19,7 @@ class DomainBlock < ApplicationRecord
 
   enum severity: [:silence, :suspend, :noop]
 
-  validates :domain, presence: true, uniqueness: true
+  validates :domain, presence: true, uniqueness: true, domain: true
 
   has_many :accounts, foreign_key: :domain, primary_key: :domain
   delegate :count, to: :accounts, prefix: true

app/models/email_domain_block.rb

@@ -12,7 +12,7 @@
 class EmailDomainBlock < ApplicationRecord
   include DomainNormalizable
 
-  validates :domain, presence: true, uniqueness: true
+  validates :domain, presence: true, uniqueness: true, domain: true
 
   def self.block?(email)
     _, domain = email.split('@', 2)

app/validators/domain_validator.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class DomainValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if value.blank?
+
+    record.errors.add(attribute, I18n.t('domain_validator.invalid_domain')) unless compliant?(value)
+  end
+
+  private
+
+  def compliant?(value)
+    Addressable::URI.new.tap { |uri| uri.host = value }
+  rescue Addressable::URI::InvalidURIError
+    false
+  end
+end

config/locales/en.yml

@@ -629,6 +629,8 @@ en:
     people:
       one: "%{count} person"
       other: "%{count} people"
+  domain_validator:
+    invalid_domain: is not a valid domain name
   errors:
     '403': You don't have permission to view this page.
     '404': The page you are looking for isn't here.