added Meta class to Item() model to test for duplicate item/list entries

src/apps/dashboard/models.py

@@ -7,6 +7,8 @@ class List(models.Model):
     
 
 class Item(models.Model):
-    text = models.TextField(default='')
+    text = models.TextField(default="")
     list = models.ForeignKey(List, default=None, on_delete=models.CASCADE)
 
+    class Meta:
+        unique_together = ("list", "text")

src/apps/dashboard/tests/test_models.py

@@ -46,3 +46,17 @@ class ListAndItemModelsTest(TestCase):
     def test_get_absolute_url(self):
         mylist = List.objects.create()
         self.assertEqual(mylist.get_absolute_url(), f"/apps/dashboard/{mylist.id}/")
+
+    def test_duplicate_items_are_invalid(self):
+        mylist = List.objects.create()
+        Item.objects.create(list=mylist, text="jklol")
+        with self.assertRaises(ValidationError):
+            item = Item(list=mylist, text="jklol")
+            item.full_clean()
+
+    def test_still_can_save_same_item_to_different_lists(self):
+        list1 = List.objects.create()
+        list2 = List.objects.create()
+        Item.objects.create(list=list1, text="nojk")
+        item = Item(list=list2, text="nojk")
+        item.full_clean() # should not raise