[FIX] shopfloor, checkout: ability to recover/restart

If the user starts to process a line, and for whatever reason he
stops there and restarts the scenario from the beginning, he should
still be able to find/recover the previous line.

For that purpose we are using the `shopfloor_user_id` field on move
lines (already used to manage currently processed lines in the Zone
picking and Location content transfer scenarios).

shopfloor/services/checkout.py

@@ -296,13 +296,16 @@ def _select_lines(self, lines):
             if line.shopfloor_checkout_done:
                 continue
             line.qty_done = line.product_uom_qty
+            line.shopfloor_user_id = self.env.user
 
         picking = lines.mapped("picking_id")
         other_lines = picking.move_line_ids - lines
         self._deselect_lines(other_lines)
 
     def _deselect_lines(self, lines):
-        lines.filtered(lambda l: not l.shopfloor_checkout_done).qty_done = 0
+        lines.filtered(lambda l: not l.shopfloor_checkout_done).write(
+            {"qty_done": 0, "shopfloor_user_id": False}
+        )
 
     def scan_line(self, picking_id, barcode):
         """Scan move lines of the stock picking
@@ -598,7 +601,9 @@ def _switch_line_qty_done(self, picking, selected_lines, switch_lines):
 
     @staticmethod
     def _filter_lines_unpacked(move_line):
-        return move_line.qty_done == 0 and not move_line.shopfloor_checkout_done
+        return (
+            move_line.qty_done == 0 or move_line.shopfloor_user_id
+        ) and not move_line.shopfloor_checkout_done
 
     @staticmethod
     def _filter_lines_to_pack(move_line):

shopfloor/tests/test_checkout_scan.py

@@ -128,3 +128,34 @@ def test_scan_document_error_location_several_pickings(self):
                 " or select a transfer manually.",
             },
         )
+
+    def test_scan_document_recover(self):
+        """If the user starts to process a line, and for whatever reason he
+        stops there and restarts the scenario from the beginning, he should
+        still be able to find the previous line.
+        """
+        picking = self._create_picking()
+        self._fill_stock_for_moves(picking.move_lines, in_package=True)
+        picking.action_assign()
+        package = picking.move_line_ids.package_id
+        # The user selects a line, then stops working in the middle of the process
+        response = self.service.dispatch(
+            "scan_document", params={"barcode": package.name}
+        )
+        data = response["data"]["select_line"]
+        self.assertEqual(data["picking"]["move_line_count"], 2)
+        self.assertEqual(len(data["picking"]["move_lines"]), 2)
+        self.assertFalse(picking.move_line_ids.shopfloor_user_id)
+        response = self.service.dispatch(
+            "select_line", params={"picking_id": picking.id, "package_id": package.id},
+        )
+        self.assertTrue(all(l.qty_done for l in picking.move_line_ids))
+        self.assertEqual(picking.move_line_ids.shopfloor_user_id, self.env.user)
+        # He restarts the scenario and try to select again the previous line
+        # to continue its job
+        response = self.service.dispatch(
+            "scan_document", params={"barcode": package.name}
+        )
+        data = response["data"]["select_line"]
+        self.assertEqual(data["picking"]["move_line_count"], 2)
+        self.assertEqual(len(data["picking"]["move_lines"]), 2)  # Lines found