Make custom emoji domains case insensitive #9351 (#9474)

* Make custom emoji domains case sensitive #9351

* Fixup style in downcase_domain to comply with codeclimate.

* switch if! to unless

* Don't use transactions, operate in batches.

Also revert spurious schema change.

app/models/custom_emoji.rb

@@ -31,6 +31,8 @@ class CustomEmoji < ApplicationRecord
 
   has_attached_file :image, styles: { static: { format: 'png', convert_options: '-coalesce -strip' } }
 
+  before_validation :downcase_domain
+
   validates_attachment :image, content_type: { content_type: 'image/png' }, presence: true, size: { less_than: LIMIT }
   validates :shortcode, uniqueness: { scope: :domain }, format: { with: /\A#{SHORTCODE_RE_FRAGMENT}\z/ }, length: { minimum: 2 }
 
@@ -73,4 +75,8 @@ class CustomEmoji < ApplicationRecord
   def remove_entity_cache
     Rails.cache.delete(EntityCache.instance.to_key(:emoji, shortcode, domain))
   end
+
+  def downcase_domain
+    self.domain = domain.downcase unless domain.nil?
+  end
 end

app/models/custom_emoji_filter.rb

@@ -26,7 +26,7 @@ class CustomEmojiFilter
     when 'remote'
       CustomEmoji.remote
     when 'by_domain'
-      CustomEmoji.where(domain: value)
+      CustomEmoji.where(domain: value.downcase)
     when 'shortcode'
       CustomEmoji.search(value)
     else

db/migrate/20181207011115_downcase_custom_emoji_domains.rb

@@ -0,0 +1,7 @@
+class DowncaseCustomEmojiDomains < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def change
+    CustomEmoji.in_batches.update_all('domain = lower(domain)')
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_12_04_215309) do
+ActiveRecord::Schema.define(version: 2018_12_07_011115) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"

spec/models/custom_emoji_spec.rb

@@ -75,4 +75,13 @@ RSpec.describe CustomEmoji, type: :model do
       end
     end
   end
+
+  describe 'pre_validation' do
+    let(:custom_emoji) { Fabricate(:custom_emoji, domain: 'wWw.MaStOdOn.CoM') }
+
+    it 'should downcase' do
+      custom_emoji.valid?
+      expect(custom_emoji.domain).to eq('www.mastodon.com')
+    end
+  end
 end