Merge branch 'refactor/user_default_preferred_language' into 'master'

Refactor user default preferred_language

See merge request gitlab-org/gitlab!71125

app/models/user.rb

@@ -455,7 +455,7 @@ class User < ApplicationRecord
   def preferred_language
     read_attribute('preferred_language') ||
       I18n.default_locale.to_s.presence_in(Gitlab::I18n.available_locales) ||
-      'en'
+      default_preferred_language
   end
 
   def active_for_authentication?
@@ -2004,6 +2004,11 @@ class User < ApplicationRecord
 
   private
 
+  # To enable JiHu repository to modify the default language options
+  def default_preferred_language
+    'en'
+  end
+
   def notification_email_verified
     return if notification_email.blank? || temp_oauth_email?
 

spec/models/user_spec.rb

@@ -343,8 +343,9 @@ RSpec.describe User do
 
         it 'falls back to english when I18n.default_locale is not an available language' do
           I18n.default_locale = :kl
+          default_preferred_language = user.send(:default_preferred_language)
 
-          expect(user.preferred_language).to eq 'en'
+          expect(user.preferred_language).to eq default_preferred_language
         end
       end
     end