sale_by_packaging: fix can_be_sold update on pkg type change

This shouldn't be required due to the compute method.
However, we experienced some cases where nested form inside the product
form fails to update the flag without this onchange.

Author: henrybackman

sale_by_packaging/models/product_packaging.py

@@ -26,6 +26,14 @@ def _compute_can_be_sold(self):
         for record in self:
             record.can_be_sold = record.packaging_type_id.can_be_sold
 
+    # This shouldn't be required due to the compute method.
+    # However, we experienced some cases where nested form inside the product
+    # form fails to update the flag without this onchange.
+    @api.onchange("packaging_type_id")
+    def _onchange_packaging_type(self):
+        for record in self:
+            record.can_be_sold = record.packaging_type_id.can_be_sold
+
     def write(self, vals):
         if "active" in vals and vals["active"] is False:
             vals["can_be_sold"] = False

sale_by_packaging/tests/test_packaging_type_can_be_sold.py

@@ -1,6 +1,8 @@
 # Copyright 2020 Camptocamp SA
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+
 from odoo.exceptions import ValidationError
+from odoo.tests.common import Form
 
 from .common import Common
 
@@ -43,3 +45,18 @@ def test_product_packaging_can_be_sold(self):
         # Changing the can_be_sold on the packaging_type does not update the packaging
         self.packaging_type_cannot_be_sold.can_be_sold = True
         self.assertEqual(self.packaging_cannot_be_sold.can_be_sold, False)
+
+
+class TestPackagingForm(Common):
+    def test_packaging_can_be_sold_default_product_form(self):
+        pkg_type_cannot_be_sold = self.packaging_type_cannot_be_sold.copy()
+        pkg_type_can_be_sold = self.packaging_type_pl.copy()
+        with Form(
+            self.env["product.packaging"],
+            view="product_packaging_type.view_product_packaging_add_type_form",
+        ) as pkg:
+            pkg.packaging_type_id = pkg_type_can_be_sold
+            self.assertTrue(pkg.can_be_sold)
+            pkg.packaging_type_id = pkg_type_cannot_be_sold
+            self.assertFalse(pkg.can_be_sold)
+            pkg.product_id = self.product