test(picklist): add test for reserved qty after partial delivery

erpnext/stock/doctype/pick_list/test_pick_list.py

@@ -645,6 +645,46 @@ class TestPickList(IntegrationTestCase):
 				if dn_item.item_code == "_Test Item 2":
 					self.assertEqual(dn_item.qty, 2)
 
+	def test_picklist_reserved_qty_validation(self):
+		from erpnext.selling.doctype.sales_order.test_sales_order import make_sales_order
+
+		warehouse = "_Test Warehouse - _TC"
+		test_stock_item = "_Test Stock Item"
+
+		# Ensure stock item exists
+		if not frappe.db.exists("Item", test_stock_item):
+			create_item(
+				item_code=test_stock_item,
+				is_stock_item=1,
+			)
+
+		# Add initial stock qty
+		make_stock_entry(item_code=test_stock_item, to_warehouse=warehouse, qty=15)
+
+		# Create SO for 10 qty
+		sales_order_1 = make_sales_order(item_code=test_stock_item, warehouse=warehouse, qty=10)
+
+		# Create and Submit picklist for SO
+		picklist_1 = create_pick_list(sales_order_1.name)
+		picklist_1.submit()
+
+		# Create DN for 5 qty
+		dn = create_delivery_note(picklist_1.name)
+		dn.items[0].qty = 5
+		dn.save()
+		dn.submit()
+
+		# Verify partly delivered state
+		picklist_1.reload()
+		self.assertEqual(picklist_1.status, "Partly Delivered")
+
+		# Create another SO (10 qty)
+		sales_order_2 = make_sales_order(item_code=test_stock_item, warehouse=warehouse, qty=10)
+
+		# Expected pick qty = 5
+		picklist_2 = create_pick_list(sales_order_2.name)
+		self.assertEqual(picklist_2.locations[0].qty, 5)
+
 	def test_picklist_with_multi_uom(self):
 		warehouse = "_Test Warehouse - _TC"
 		item = make_item(properties={"uoms": [dict(uom="Box", conversion_factor=24)]}).name