[IMP] product_contract: consider recurrence in SO lines amounts

Prior to f50e15d and the introduction of "sale.order.line.contract.mixin"
the recurrence on a SO line used to be the quantity, thus the recurrence impacted the amounts of the line.
Now that the recurrence is a separated field, we need to add it explicitly to the computation of the amounts.

Author: qgroulard

product_contract/models/sale_order_line.py

@@ -278,3 +278,28 @@ def _get_contract_name_format(self):
             - Date: {date_text}
             """
         )
+
+    def _prepare_base_line_for_taxes_computation(self, **kwargs):
+        """
+        This is the base method for all line amounts computations.
+        For 'is_contract' lines, we multiply the quantity by the recurrence.
+        """
+        self.ensure_one()
+        if self.is_contract:
+            return self.env["account.tax"]._prepare_base_line_for_taxes_computation(
+                self,
+                **{
+                    "tax_ids": self.tax_id,
+                    "quantity": self.product_uom_qty * self.recurrence_number,
+                    "partner_id": self.order_id.partner_id,
+                    "currency_id": self.order_id.currency_id
+                    or self.order_id.company_id.currency_id,
+                    "rate": self.order_id.currency_rate,
+                    **kwargs,
+                },
+            )
+        return super()._prepare_base_line_for_taxes_computation(**kwargs)
+
+    @api.depends("recurrence_number")
+    def _compute_amount(self):
+        return super()._compute_amount()

product_contract/tests/test_sale_order.py

@@ -615,3 +615,26 @@ def test_order_line_date_start_confirm(self):
             sale.order_line.contract_id.contract_line_ids.date_start,
             fields.Date.to_date("2025-02-28"),
         )
+
+    def test_compute_amount(self):
+        """
+        Check that recurrence is taken into account in line amounts.
+        """
+        tax = self.env["account.tax"].create(
+            {
+                "name": "10% tax",
+                "amount_type": "percent",
+                "amount": 10,
+            }
+        )
+        self.order_line1.update(
+            {
+                "price_unit": 100,
+                "product_uom_qty": 10,
+                "recurrence_number": 24,
+                "tax_id": [(4, tax.id)],
+            }
+        )
+        self.assertEqual(self.order_line1.price_subtotal, 24000)
+        self.assertEqual(self.order_line1.price_tax, 2400)
+        self.assertEqual(self.order_line1.price_total, 26400)

product_contract/views/sale_order.xml

@@ -121,7 +121,7 @@
                     domain="[('contract_id','=',contract_id)]"
                     optional="hide"
                 />
-                <field name="recurrence_number" optional="hide" />
+                <field name="recurrence_number" optional="show" />
                 <field name="recurrence_interval" optional="hide" />
                 <field name="recurring_interval" optional="hide" />
                 <field name="recurring_rule_type" optional="hide" />