KB Prep: Refactor & backport User#locale method

app/models/user.rb

@@ -930,6 +930,11 @@ try to find correct name
     firstname.blank? && lastname.blank?
   end
 
+  # get locale of user or system if user's own is not set
+  def locale
+    preferences.fetch(:locale) { Setting.get('locale_default') }
+  end
+
   private
 
   def check_name

db/migrate/20190328000000_rename_locale_on_users.rb

@@ -0,0 +1,16 @@
+class RenameLocaleOnUsers < ActiveRecord::Migration[5.1]
+  def up
+    return if !Setting.find_by(name: 'system_init_done')
+    return if ActiveRecord::Base.connection.columns('users').map(&:name).exclude?('locale')
+
+    ActiveRecord::Migration.rename_column(:users, :locale, :_locale)
+    ObjectManager::Attribute.find_by(name: 'locale').update(name: '_locale')
+  end
+
+  def down
+    return if ActiveRecord::Base.connection.columns('users').map(&:name).exclude?('_locale')
+
+    ActiveRecord::Migration.rename_column(:users, :_locale, :locale)
+    ObjectManager::Attribute.find_by(name: '_locale').update(name: 'locale')
+  end
+end

spec/db/migrate/rename_locale_on_users_spec.rb

@@ -0,0 +1,43 @@
+require 'rails_helper'
+
+RSpec.describe RenameLocaleOnUsers, type: :db_migration do
+  context 'when custom OMA attribute #locale exists', db_strategy: :reset do
+    before do
+      ObjectManager::Attribute.add(
+        force:         true,
+        object:        'User',
+        name:          'locale',
+        display:       'Locale',
+        data_type:     'select',
+        data_option:   {
+          'default' => '',
+          'options' => {},
+        },
+        active:        true,
+        position:      20,
+        to_migrate:    true,
+        created_by_id: 1,
+        updated_by_id: 1,
+      )
+
+      ObjectManager::Attribute.migration_execute
+    end
+
+    it 'renames #locale' do
+      expect { migrate }
+        .to change { ActiveRecord::Base.connection.columns('users').map(&:name) }
+        .to not_include('locale')
+        .and include('_locale')
+
+      expect(ObjectManager::Attribute.exists?(name: 'locale')).to be(false)
+      expect(ObjectManager::Attribute.exists?(name: '_locale')).to be(true)
+    end
+  end
+
+  context 'when no #locale attribute exists' do
+    it 'makes no changes to the "users" table' do
+      expect { migrate }
+        .not_to change { ActiveRecord::Base.connection.columns('users') }
+    end
+  end
+end

spec/models/user_spec.rb

@@ -595,6 +595,27 @@ RSpec.describe User, type: :model do
         end
       end
     end
+
+    describe '#locale' do
+      subject(:user) { create(:user, preferences: preferences) }
+
+      context 'with no #preferences[:locale]' do
+        let(:preferences) { {} }
+        before { Setting.set('locale_default', 'foo') }
+
+        it 'returns the system-wide default locale' do
+          expect(user.locale).to eq('foo')
+        end
+      end
+
+      context 'with a #preferences[:locale]' do
+        let(:preferences) { { locale: 'bar' } }
+
+        it 'returns the user’s configured locale' do
+          expect(user.locale).to eq('bar')
+        end
+      end
+    end
   end
 
   describe 'Attributes:' do