Allow internal users to switch their current study group

app/models/internal_user.rb

@@ -37,8 +37,4 @@ class InternalUser < User
   def displayname
     name
   end
-
-  def current_study_group_id
-    study_groups.find_by(external_id: nil)&.id
-  end
 end

spec/factories/shared_traits.rb

@@ -30,7 +30,7 @@ FactoryBot.define do
       end
 
       user.study_group_memberships.update(role: 'teacher') if evaluator.teacher_in_study_group
-      user.store_current_study_group_id(user.study_group_memberships.first)
+      user.store_current_study_group_id(user.study_group_memberships.first.study_group_id)
     end
   end
 end