Add a None check before using property values, with tests

src/shop/models.py

@@ -615,7 +615,7 @@ def labels(self) -> list:
                 "text": "Bundle",
             })
 
-        if self.stock_amount is not None:
+        if self.left_in_stock is not None:
             if self.left_in_stock < 1 or not self.is_time_available:
                 labels.insert(0, {
                     "type": "sold_out",
@@ -631,11 +631,12 @@ def labels(self) -> list:
                     "text": f"Only {self.left_in_stock} left!",
                 })
 
-        if self.available_for_days < 20:
-            labels.append({
-                "type": "ending_soon",
-                "text": f"Sales end in {self.available_for_days} days!",
-            })
+        if self.available_for_days is not None:
+            if self.available_for_days > 0 and self.available_for_days < 20:
+                labels.append({
+                    "type": "ending_soon",
+                    "text": f"Sales end in {self.available_for_days} days!",
+                })
 
         return labels
 

src/shop/tests.py

@@ -151,12 +151,29 @@ def test_labels_for_product_with_stock_below_or_equal_to_10(self):
 
     def test_labels_for_product_ending_within_20_days(self):
         """Test the product returns a 'ending_soon' label object."""
+        # Without upper availability
         available_in = DateTimeTZRange(
             lower=timezone.now(),
-            upper=timezone.now() + timezone.timedelta(6),
+            upper=None,
+        )
+        product = ProductFactory(available_in=available_in)
+
+        assert len(product.labels) == 0
+
+        # Without lower availability
+        available_in = DateTimeTZRange(
+            lower=None,
+            upper=timezone.now(),
         )
+        product = ProductFactory(available_in=available_in)
+
+        assert len(product.labels) == 0
 
         # With stock
+        available_in = DateTimeTZRange(
+            lower=timezone.now(),
+            upper=timezone.now() + timezone.timedelta(6),
+        )
         product = ProductFactory(stock_amount=11, available_in=available_in)
 
         result = product.labels[0]