Extract event delete logic to Event.batch_delete

app/models/event.rb

@@ -21,6 +21,10 @@ def self.with_teacher(username)
     filter(:teacher_ids.pg_array.contains([username]))
   end
 
+  def self.batch_delete(ids)
+    where(id: ids, deleted: false).update(deleted: true, applied_schedule_exception_ids: nil)
+  end
+
   def period
     Period.new(starts_at, ends_at)
   end

app/roles/planned_timetable_slot.rb

@@ -19,7 +19,7 @@ def generate_events(faculty_semester, semester_period)
   def clear_extra_events(planned_events)
     all_events = Event.where(timetable_slot_id: id, deleted: false)
     extra_events = filter_extra_events(all_events, planned_events)
-    Event.where(id: extra_events.map(&:id), deleted: false).update(deleted: true, applied_schedule_exception_ids: nil)
+    Event.batch_delete(extra_events.map(&:id))
   end
 
   private

spec/models/event_spec.rb

@@ -73,4 +73,29 @@ def with_teacher(person_id)
 
   end
 
+  describe '.batch_delete' do
+    let!(:event) { Fabricate(:event, applied_schedule_exception_ids: [42]) }
+
+    it 'sets deleted flag for given events' do
+      expect {
+        described_class.batch_delete([event.id])
+        event.refresh
+      }.to change(event, :deleted).from(false).to(true)
+    end
+
+    it 'does not mark other events' do
+      expect {
+        described_class.batch_delete([])
+        event.refresh
+      }.not_to change(event, :deleted).from(false)
+    end
+
+    it 'cleans applied_schedule_exception_ids for given events' do
+      expect {
+        described_class.batch_delete([event.id])
+        event.refresh
+      }.to change(event, :applied_schedule_exception_ids).from([42]).to(nil)
+    end
+  end
+
 end