Refactoring to use constrain instead of write

commown_devices/models/crm_lead.py

@@ -32,15 +32,11 @@ def action_generate_picking(self):
             "context": {"default_lead_id": self.id},
         }
 
-    @api.multi
-    def write(self, values):
-        res = super().write(values)
-        stage_id = values.get("stage_id")
-        if stage_id:
-            stage = self.env["crm.stage"].browse(stage_id)
-            if "[stock: check-has-picking]" in stage.name:
+    @api.constrains("stage_id")
+    def _check_picking_on_stage_change(self):
+        if self.stage_id.name:
+            if "[stock: check-has-picking]" in self.stage_id.name:
                 self.action_check_waiting_picking()
-        return res
 
     def action_check_waiting_picking(self):
         if self.so_line_id.product_id.product_tmpl_id.storable_product_id:

commown_devices/tests/test_crm_lead.py

@@ -1,5 +1,5 @@
 from odoo import fields
-from odoo.exceptions import UserError
+from odoo.exceptions import UserError, ValidationError
 
 from .common import DeviceAsAServiceTC
 
@@ -21,9 +21,10 @@ def test_picking_confirmation_on_delivery(self):
 
         # Should not be able to put the lead to a "go" column without a picking:
         stage = self.env["crm.stage"].create({"name": "GO [stock: check-has-picking]"})
-        with self.assertRaises(UserError) as err:
-            lead.stage_id = stage.id
-        self.assertEqual("Lead has no assigned picking.", err.exception.name)
+        with self.assertRaises(ValidationError):
+            with self.assertRaises(UserError) as err:
+                lead.stage_id = stage.id
+            self.assertEqual("Lead has no assigned picking.", err.exception.name)
 
         picking = lead.contract_id.send_device(quant)
         self.assertEqual(picking.mapped("move_lines.product_qty"), [1.0])