test: add test for validating sales invoice qty after return

erpnext/stock/doctype/delivery_note/test_delivery_note.py

@@ -6,7 +6,7 @@ import json
 from collections import defaultdict
 
 import frappe
-from frappe.tests import IntegrationTestCase
+from frappe.tests import IntegrationTestCase, change_settings
 from frappe.utils import add_days, cstr, flt, getdate, nowdate, nowtime, today
 
 from erpnext.accounts.doctype.account.test_account import get_inventory_account
@@ -1023,6 +1023,30 @@ class TestDeliveryNote(IntegrationTestCase):
 		self.assertEqual(dn2.per_billed, 100)
 		self.assertEqual(dn2.status, "Completed")
 
+	@change_settings("Accounts Settings", {"delete_linked_ledger_entries": True})
+	def test_sales_invoice_qty_after_return(self):
+		from erpnext.stock.doctype.delivery_note.delivery_note import make_sales_return
+
+		dn = create_delivery_note(qty=10)
+
+		dnr1 = make_sales_return(dn.name)
+		dnr1.get("items")[0].qty = -3
+		dnr1.save().submit()
+
+		dnr2 = make_sales_return(dn.name)
+		dnr2.get("items")[0].qty = -2
+		dnr2.save().submit()
+
+		si = make_sales_invoice(dn.name)
+		si.save().submit()
+
+		self.assertEqual(si.get("items")[0].qty, 5)
+
+		si.reload().cancel().delete()
+		dnr1.reload().cancel().delete()
+		dnr2.reload().cancel().delete()
+		dn.reload().cancel().delete()
+
 	def test_dn_billing_status_case3(self):
 		# SO -> DN1 -> SI and SO -> SI and SO -> DN2
 		from erpnext.selling.doctype.sales_order.sales_order import make_delivery_note