[FIX] sale_loyalty_delivery: default sequence if no reward line

The commit: https://github.com/odoo/odoo/commit/58a88b7731ace08ca106f3df47dd455520136248
prevents the deletion of a 'free shipping' line
if it is not the last one in the cart.

The fix: https://github.com/odoo/odoo/commit/7004b17ee5433e3b14561358348b42326f549261
calculates the sequence of the 'free shipping' line
so that it is the last one in the cart.

Issue:
In case we have enough points to get the 'free shipping' reward
without the actual products in the cart,
if we want to delete the product, we raise an error.

Cause:
It is no longer possible to calculate the free shipping sequence
as this is based on the non-reward lines (and we have just deleted this line).

Solution:
We have to add a default value for the sequence
in case the 'free shipping' is the last item in the cart.

opw-3269594

closes odoo/odoo#120749

X-original-commit: 67b3f6dee2e108c32ec561ed32734a147299d8d8
Signed-off-by: Lefebvre Thomas (thle) <thle@odoo.com>

addons/sale_loyalty_delivery/models/sale_order.py

@@ -30,7 +30,7 @@ class SaleOrder(models.Model):
             'product_uom': reward.discount_line_product_id.uom_id.id,
             'order_id': self.id,
             'is_reward_line': True,
-            'sequence': max(self.order_line.filtered(lambda x: not x.is_reward_line).mapped('sequence')) + 1,
+            'sequence': max(self.order_line.filtered(lambda x: not x.is_reward_line).mapped('sequence'), default=0) + 1,
             'tax_id': [(Command.CLEAR, 0, 0)] + [(Command.LINK, tax.id, False) for tax in taxes],
         }]
 

addons/sale_loyalty_delivery/tests/test_free_shipping_reward.py

@@ -277,3 +277,43 @@ class TestSaleCouponProgramRules(TestSaleCouponCommon):
         self._auto_rewards(order, programs)
         # 872.73 - (20% of 1 iPad) = 872.73 - 58.18 = 814.55
         self.assertAlmostEqual(order.amount_untaxed, 1105.46, 2, "One large cabinet should be discounted by 20%")
+
+    def test_free_shipping_reward_last_line(self):
+        """
+            The free shipping reward cannot be removed if it is the last item in the sale order.
+            However, we calculate its sequence so that it is the last item in the sale order.
+            This can create an error if a default sequence is not determined.
+        """
+        self.immediate_promotion_program.active = False
+        # Create a loyalty program
+        loyalty_program = self.env['loyalty.program'].create({
+            'name': 'GIFT Free Shipping',
+            'program_type': 'loyalty',
+            'applies_on': 'both',
+            'trigger': 'auto',
+            'rule_ids': [(0, 0, {
+                    'reward_point_mode': 'money',
+                    'reward_point_amount': 1,
+                })],
+            'reward_ids': [(0, 0, {
+                'reward_type': 'shipping',
+                'required_points': 100,
+            })],
+        })
+        # Add points to a partner to trigger the promotion
+        loyalty_card = self.env['loyalty.card'].create({
+            'program_id': loyalty_program.id,
+            'partner_id': self.steve.id,
+            'points': 250,
+        })
+        order = self.env['sale.order'].create({
+            'partner_id': self.steve.id,
+        })
+        # Check if we can claim the free shipping reward
+        order._update_programs_and_rewards()
+        claimable_rewards = order._get_claimable_rewards()
+        self.assertEqual(len(claimable_rewards), 1)
+        # Try to apply the loyalty card to the sale order
+        self._apply_promo_code(order, loyalty_card.code)
+        # Check if there is an error in the sequence
+        # via `_apply_program_reward` in `apply_promo_code` method