[FIX] sale_stock_return_request: Fix tests

Previously, they were tricking how stock works, and an update over Odoo
has revealed the trick, so let's do things properly, adjusting the
method to do the deliveries, and changing quantities to the proper ones.

Fixes OCA#3936

Author: pedrobaeza

sale_stock_return_request/tests/test_stock_return_request.py

@@ -1,4 +1,5 @@
 # Copyright 2019 Tecnativa - David Vidal
+# Copyright 2025 Tecnativa - Pedro M. Baeza
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
 from odoo import Command
@@ -53,48 +54,27 @@ def setUpClass(cls):
         # Confirm all the sale orders
         for order in cls.sale_orders:
             order.action_confirm()
-        # Adjust quants to avoid reservation quircks
-        quant_lot_1 = cls.env["stock.quant"].search(
-            [
-                ("product_id", "=", cls.prod_3.id),
-                ("lot_id", "=", cls.prod_3_lot1.id),
-                ("location_id", "=", cls.wh1.lot_stock_id.id),
-            ]
-        )
-        quant_lot_2 = cls.env["stock.quant"].search(
-            [
-                ("product_id", "=", cls.prod_3.id),
-                ("lot_id", "=", cls.prod_3_lot2.id),
-                ("location_id", "=", cls.wh1.lot_stock_id.id),
-            ]
-        )
-        quant_lot_1.reserved_quantity = 90.0
-        quant_lot_2.reserved_quantity = 10.0
         # Deliver products. For each picking:
-        # 10 units of TSTPROD3LOT0001 -> -20 units of 90 already existing
-        # 2 units of TSTPROD3LOT0002 -> -4 units of 10 already existing
+        # 10 units of TSTPROD3LOT0001 -> -20 units of 70 already existing
+        # 4 units of TSTPROD3LOT0002 -> -8 units of 0 already existing
         for picking in cls.sale_orders.mapped("picking_ids"):
-            for ml in picking.move_line_ids:
-                ml.write(
-                    {
-                        "lot_id": cls.prod_3_lot1.id,
-                        "quantity": 10.0,
-                    }
-                )
-                ml.create(
-                    {
-                        "move_id": ml.move_id.id,
-                        "picking_id": ml.picking_id.id,
-                        "location_id": ml.location_id.id,
-                        "location_dest_id": ml.location_dest_id.id,
-                        "product_uom_id": ml.product_uom_id.id,
-                        "product_id": cls.prod_3.id,
-                        "lot_id": cls.prod_3_lot2.id,
-                        "quantity": 4.0,
-                    }
-                )
+            picking.move_line_ids.unlink()
+            move = picking.move_ids
+            vals = {
+                "move_id": move.id,
+                "picking_id": picking.id,
+                "location_id": move.location_id.id,
+                "location_dest_id": move.location_dest_id.id,
+                "product_uom_id": move.product_uom.id,
+                "product_id": move.product_id.id,
+                "lot_id": cls.prod_3_lot1.id,
+                "quantity": 10.0,
+            }
+            cls.env["stock.move.line"].create(vals)
+            vals["lot_id"] = cls.prod_3_lot2.id
+            vals["quantity"] = 4
+            cls.env["stock.move.line"].create(vals)
             picking.button_validate()
-        quant_lot_1.reserved_quantity = quant_lot_2.reserved_quantity = 0.0
 
     def test_01_return_sale_stock_from_customer(self):
         """Return stock from customer and the corresponding
@@ -140,16 +120,16 @@ def test_01_return_sale_stock_from_customer(self):
         self.assertTrue(
             all([True if x == "done" else False for x in pickings.mapped("state")])
         )
-        # For lot TSTPROD3LOT0001 we had 70 units
+        # For lot TSTPROD3LOT0001 we had 50 units
         prod_3_qty_lot_1 = self.prod_3.with_context(
             location=self.wh1.lot_stock_id.id, lot_id=self.prod_3_lot1.id
         ).qty_available
-        # For lot TSTPROD3LOT0002 we had 2 units
+        # For lot TSTPROD3LOT0002 we had -8 units
         prod_3_qty_lot_2 = self.prod_3.with_context(
             location=self.wh1.lot_stock_id.id, lot_id=self.prod_3_lot2.id
         ).qty_available
-        self.assertAlmostEqual(prod_3_qty_lot_1, 82.0)
-        self.assertAlmostEqual(prod_3_qty_lot_2, 6.0)
+        self.assertAlmostEqual(prod_3_qty_lot_1, 62.0)
+        self.assertAlmostEqual(prod_3_qty_lot_2, -4.0)
         # There were 28 units in the sale orders.
         self.assertAlmostEqual(
             sum(sale_orders.mapped("order_line.qty_delivered")), 12.0