sale_triple_discount: Consolidate discount in std field

Until now, the triple discount feature did use the standard Odoo field
as the first discount field, adding only extra fields for the second
and the third discount. This implied we had to override any function
using discount to consider the other discounts properly.

By adding an extra field discount1 to store the first discount, it allows
to redefine the standard discount field to a computed field that will
consolidate the triple discount from the other fields, and avoid the
need to redefine anything relying on the discount field as it will
already consider the triple discounts.

Author: grindtildeath

sale_triple_discount/migrations/16.0.2.0.0/post-migrate.py

@@ -0,0 +1,23 @@
+# Copyright 2024 Camptocamp SA
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+
+import openupgrade
+
+
+@openupgrade.logging()
+def compute_discount(env):
+    env["sale.order.line"].search(
+        [
+            "|",
+            "|",
+            ("discount1", "!=", 0),
+            ("discount2", "!=", 0),
+            ("discount3", "!=", 0),
+        ]
+    )
+    env["sale.order.line"]._compute_discount()
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    compute_discount(env)

sale_triple_discount/migrations/16.0.2.0.0/pre-migrate.py

@@ -0,0 +1,29 @@
+# Copyright 2024 Camptocamp SA
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+import openupgrade
+
+
+def migrate_discount_to_discount1():
+    openupgrade.add_fields(
+        [
+            (
+                "discount1",
+                "sale.order.line",
+                "sale_order_line",
+                "float",
+                "numeric",
+                "sale_triple_discount",
+                0.0,
+            )
+        ]
+    )
+    openupgrade.logged_query(
+        """
+        UPDATE sale_order_line
+        SET discount1 = discount;
+        """
+    )
+
+
+def migrate(cr, version):
+    migrate_discount_to_discount1()

sale_triple_discount/models/sale_order_line.py

@@ -11,6 +11,11 @@
 class SaleOrderLine(models.Model):
     _inherit = "sale.order.line"
 
+    discount1 = fields.Float(
+        string="Disc. 1 (%)",
+        digits="Discount",
+        default=0.0,
+    )
     discount2 = fields.Float(
         string="Disc. 2 (%)",
         digits="Discount",
@@ -62,16 +67,27 @@ def _multiplicative_discount(self):
 
     @api.model
     def _discount_fields(self):
-        return ["discount", "discount2", "discount3"]
+        return ["discount1", "discount2", "discount3"]
 
-    @api.depends("discount2", "discount3", "discounting_type")
-    def _compute_amount(self):
-        prev_values = self.triple_discount_preprocess()
-        res = super()._compute_amount()
-        self.triple_discount_postprocess(prev_values)
-        return res
+    # pylint: disable=W8110
+    @api.depends("discount1", "discount2", "discount3", "discounting_type")
+    def _compute_discount(self):
+        super()._compute_discount()
+        for line in self:
+            # Reset discount if not done in super
+            if not (
+                line.order_id.pricelist_id
+                and line.order_id.pricelist_id.discount_policy == "without_discount"
+            ):
+                line.discount = 0.0
+            line.discount += line._get_final_discount()
 
     _sql_constraints = [
+        (
+            "discount1_limit",
+            "CHECK (discount1 <= 100.0)",
+            "Discount 1 must be lower or equal than 100%.",
+        ),
         (
             "discount2_limit",
             "CHECK (discount2 <= 100.0)",
@@ -90,51 +106,14 @@ def _prepare_invoice_line(self, **kwargs):
         more discount fields to the invoice lines
         """
         res = super()._prepare_invoice_line(**kwargs)
-        res.update({"discount2": self.discount2, "discount3": self.discount3})
+        if self.discounting_type == "multiplicative":
+            res.update(
+                {
+                    "discount1": self.discount1,
+                    "discount2": self.discount2,
+                    "discount3": self.discount3,
+                }
+            )
+        else:
+            res.update({"discount1": self.discount})
         return res
-
-    def triple_discount_preprocess(self):
-        """Prepare data for post processing.
-
-        Save the values of the discounts in a dictionary,
-        to be restored in postprocess.
-        Resetting every discount except the main one to 0.0 avoids issues if
-        this method is called multiple times.
-        Updating the cache provides consistency through re-computations."""
-        prev_values = dict()
-        self.invalidate_cache(fnames=self._discount_fields(), ids=self.ids)
-        for line in self:
-            prev_values[line] = {
-                fname: line[fname] for fname in self._discount_fields()
-            }
-
-            vals = {fname: 0 for fname in self._discount_fields()}
-            vals["discount"] = line._get_final_discount()
-
-            line._cache.update(vals)
-        return prev_values
-
-    @api.model
-    def triple_discount_postprocess(self, prev_values):
-        """Restore the discounts of the lines in the dictionary prev_values.
-        Updating the cache provides consistency through re-computations."""
-        self.invalidate_cache(
-            fnames=self._discount_fields(),
-            ids=[line.id for line in list(prev_values.keys())],
-        )
-        for line, prev_vals_dict in list(prev_values.items()):
-            line.update(prev_vals_dict)
-
-    def _convert_to_tax_base_line_dict(self):
-        self.ensure_one()
-        return self.env["account.tax"]._convert_to_tax_base_line_dict(
-            self,
-            partner=self.order_id.partner_id,
-            currency=self.order_id.currency_id,
-            product=self.product_id,
-            taxes=self.tax_id,
-            price_unit=self.price_unit,
-            quantity=self.product_uom_qty,
-            discount=self._get_final_discount(),
-            price_subtotal=self.price_subtotal,
-        )

sale_triple_discount/tests/test_sale_triple_discount.py

@@ -51,8 +51,8 @@ def setUpClass(cls):
 
     def test_01_sale_order_classic_discount(self):
         """Tests with single discount"""
-        self.so_line1.discount = 50.0
-        self.so_line2.discount = 75.0
+        self.so_line1.discount1 = 50.0
+        self.so_line2.discount1 = 75.0
         self.assertAlmostEqual(self.so_line1.price_subtotal, 300.0)
         self.assertAlmostEqual(self.so_line2.price_subtotal, 150.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 450.0)
@@ -65,19 +65,22 @@ def test_02_sale_order_simple_triple_discount(self):
         """Tests on a single line"""
         self.so_line2.unlink()
         # Divide by two on every discount:
-        self.so_line1.discount = 50.0
+        self.so_line1.discount1 = 50.0
         self.so_line1.discount2 = 50.0
         self.so_line1.discount3 = 50.0
+        self.assertAlmostEqual(self.so_line1.discount, 87.5)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 75.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 75.0)
         self.assertAlmostEqual(self.order.amount_tax, 11.25)
         # Unset first discount:
-        self.so_line1.discount = 0.0
+        self.so_line1.discount1 = 0.0
+        self.assertAlmostEqual(self.so_line1.discount, 75)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 150.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 150.0)
         self.assertAlmostEqual(self.order.amount_tax, 22.5)
         # Set a charge instead:
         self.so_line1.discount2 = -50.0
+        self.assertAlmostEqual(self.so_line1.discount, 25)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 450.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 450.0)
         self.assertAlmostEqual(self.order.amount_tax, 67.5)
@@ -88,10 +91,11 @@ def test_02_sale_order_simple_triple_discount(self):
             67.5,
         )
         # set discount_type to additive
-        self.so_line1.discount = 10.0
+        self.so_line1.discount1 = 10.0
         self.so_line1.discount2 = 10.0
         self.so_line1.discount3 = 10.0
         self.so_line1.discounting_type = "additive"
+        self.assertAlmostEqual(self.so_line1.discount, 30.0)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 420.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 420.0)
         self.assertAlmostEqual(self.order.amount_tax, 63.0)
@@ -102,47 +106,54 @@ def test_02_sale_order_simple_triple_discount(self):
             63.0,
         )
         # set discount over 100%
-        self.so_line1.discount = 30.0
+        self.so_line1.discount1 = 30.0
         self.so_line1.discount2 = 70.0
         self.so_line1.discount3 = 50.0
+        self.assertAlmostEqual(self.so_line1.discount, 100.0)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 0.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 0.0)
         self.assertAlmostEqual(self.order.amount_tax, 0.0)
         # set discount_type to multiplicative
-        self.so_line1.discount = 50.0
+        self.so_line1.discount1 = 50.0
         self.so_line1.discount2 = 50.0
         self.so_line1.discount3 = 50.0
         self.so_line1.discounting_type = "multiplicative"
+        self.assertAlmostEqual(self.so_line1.discount, 87.5)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 75.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 75.0)
         self.assertAlmostEqual(self.order.amount_tax, 11.25)
 
     def test_03_sale_order_complex_triple_discount(self):
         """Tests on multiple lines"""
-        self.so_line1.discount = 50.0
+        self.so_line1.discount1 = 50.0
         self.so_line1.discount2 = 50.0
         self.so_line1.discount3 = 50.0
+        self.assertAlmostEqual(self.so_line1.discount, 87.5)
         self.assertAlmostEqual(self.so_line1.price_subtotal, 75.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 675.0)
         self.assertAlmostEqual(self.order.amount_tax, 101.25)
         # additive discount
         self.so_line2.discount3 = 50.0
+        self.assertAlmostEqual(self.so_line2.discount, 50.0)
         self.assertAlmostEqual(self.so_line2.price_subtotal, 300.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 375.0)
         self.assertAlmostEqual(self.order.amount_tax, 56.25)
         self.so_line2.discounting_type = "additive"
         self.so_line2.discount2 = 10.0
+        self.assertAlmostEqual(self.so_line2.discount, 60.0)
         self.assertAlmostEqual(self.so_line2.price_subtotal, 240.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 315.0)
         self.assertAlmostEqual(self.order.amount_tax, 47.25)
         # multiplicative discount
         self.so_line2.discount2 = 0.0
         self.so_line2.discount3 = 50.0
+        self.assertAlmostEqual(self.so_line2.discount, 50.0)
         self.assertAlmostEqual(self.so_line2.price_subtotal, 300.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 375.0)
         self.assertAlmostEqual(self.order.amount_tax, 56.25)
         self.so_line2.discounting_type = "multiplicative"
         self.so_line2.discount2 = 10.0
+        self.assertAlmostEqual(self.so_line1.discount, 60.0)
         self.assertAlmostEqual(self.so_line2.price_subtotal, 270.0)
         self.assertAlmostEqual(self.order.amount_untaxed, 345.0)
         self.assertAlmostEqual(self.order.amount_tax, 51.75)
@@ -155,6 +166,7 @@ def test_04_sale_order_triple_discount_invoicing(self):
         self.so_line1.discount3 = 50.0
         self.so_line2.discount3 = 50.0
         self.order.action_confirm()
+        # FIXME: AFAIK this is another module messing and shouldn't be in this test
         if self.order.state == "waiting_approval":
             self.order.action_approve()
             self.assertAlmostEqual(self.order.state, "approved")
@@ -164,6 +176,9 @@ def test_04_sale_order_triple_discount_invoicing(self):
         self.assertAlmostEqual(
             self.so_line1.discount, invoice.invoice_line_ids[0].discount
         )
+        self.assertAlmostEqual(
+            self.so_line1.discount1, invoice.invoice_line_ids[0].discount1
+        )
         self.assertAlmostEqual(
             self.so_line1.discount2, invoice.invoice_line_ids[0].discount2
         )
@@ -173,6 +188,9 @@ def test_04_sale_order_triple_discount_invoicing(self):
         self.assertAlmostEqual(
             self.so_line1.price_subtotal, invoice.invoice_line_ids[0].price_subtotal
         )
+        self.assertAlmostEqual(
+            self.so_line2.discount, invoice.invoice_line_ids[1].discount
+        )
         self.assertAlmostEqual(
             self.so_line2.discount3, invoice.invoice_line_ids[1].discount3
         )
@@ -184,7 +202,7 @@ def test_04_sale_order_triple_discount_invoicing(self):
     def test_05_round_globally(self):
         """Tests on multiple lines when 'round_globally' is active"""
         self.env.user.company_id.tax_calculation_rounding_method = "round_globally"
-        self.so_line1.discount = 50.0
+        self.so_line1.discount1 = 50.0
         self.so_line1.discount2 = 50.0
         self.so_line1.discount3 = 50.0
         self.assertEqual(self.so_line1.price_subtotal, 75.0)
@@ -197,11 +215,11 @@ def test_05_round_globally(self):
 
     def test_06_discount_0(self):
         self.so_line1.discounting_type = "additive"
-        self.so_line1.discount = 0.0
+        self.so_line1.discount1 = 0.0
         self.so_line1.discount2 = 0.0
         self.so_line1.discount3 = 0.0
         self.so_line2.discounting_type = "additive"
-        self.so_line2.discount = 0.0
+        self.so_line2.discount1 = 0.0
         self.so_line2.discount2 = 0.0
         self.so_line2.discount3 = 0.0
         self.assertAlmostEqual(self.so_line1.price_subtotal, 600.0)