fix: Discount and taxes in return document should follow the referenc…

…e document (#41911)

* fix: Discount and taxes in return document should follow the reference document

* fix: Ignore Pricing rule on debit/credit note if created against PI/SI with test cases

* fix: linter issue

erpnext/accounts/doctype/pricing_rule/test_pricing_rule.py

@@ -6,7 +6,9 @@
 
 import frappe
 
+from erpnext.accounts.doctype.purchase_invoice.test_purchase_invoice import make_purchase_invoice
 from erpnext.accounts.doctype.sales_invoice.test_sales_invoice import create_sales_invoice
+from erpnext.controllers.sales_and_purchase_return import make_return_doc
 from erpnext.selling.doctype.sales_order.test_sales_order import make_sales_order
 from erpnext.stock.doctype.item.test_item import make_item
 from erpnext.stock.get_item_details import get_item_details
@@ -1311,6 +1313,69 @@ def test_validation_on_mixed_condition_with_recursion(self):
 		pricing_rule.is_recursive = True
 		self.assertRaises(frappe.ValidationError, pricing_rule.save)
 
+	def test_ignore_pricing_rule_for_credit_note(self):
+		frappe.delete_doc_if_exists("Pricing Rule", "_Test Pricing Rule")
+		pricing_rule = make_pricing_rule(
+			discount_percentage=20,
+			selling=1,
+			buying=1,
+			priority=1,
+			title="_Test Pricing Rule",
+		)
+
+		si = create_sales_invoice(do_not_submit=True, customer="_Test Customer 1", qty=1)
+		item = si.items[0]
+		si.submit()
+		self.assertEqual(item.discount_percentage, 20)
+		self.assertEqual(item.rate, 80)
+
+		# change discount on pricing rule
+		pricing_rule.discount_percentage = 30
+		pricing_rule.save()
+
+		credit_note = make_return_doc(si.doctype, si.name)
+		credit_note.save()
+		self.assertEqual(credit_note.ignore_pricing_rule, 1)
+		self.assertEqual(credit_note.pricing_rules, [])
+		self.assertEqual(credit_note.items[0].discount_percentage, 20)
+		self.assertEqual(credit_note.items[0].rate, 80)
+		self.assertEqual(credit_note.items[0].pricing_rules, None)
+
+		credit_note.delete()
+		si.cancel()
+
+	def test_ignore_pricing_rule_for_debit_note(self):
+		frappe.delete_doc_if_exists("Pricing Rule", "_Test Pricing Rule")
+		pricing_rule = make_pricing_rule(
+			discount_percentage=20,
+			buying=1,
+			priority=1,
+			title="_Test Pricing Rule",
+		)
+
+		pi = make_purchase_invoice(do_not_submit=True, supplier="_Test Supplier 1", qty=1)
+		item = pi.items[0]
+		pi.submit()
+		self.assertEqual(item.discount_percentage, 20)
+		self.assertEqual(item.rate, 40)
+
+		# change discount on pricing rule
+		pricing_rule.discount_percentage = 30
+		pricing_rule.save()
+
+		# create debit note from purchase invoice
+		debit_note = make_return_doc(pi.doctype, pi.name)
+		debit_note.save()
+
+		self.assertEqual(debit_note.ignore_pricing_rule, 1)
+		self.assertEqual(debit_note.pricing_rules, [])
+		self.assertEqual(debit_note.items[0].discount_percentage, 20)
+		self.assertEqual(debit_note.items[0].rate, 40)
+		self.assertEqual(debit_note.items[0].pricing_rules, None)
+
+		debit_note.delete()
+		pi.cancel()
+
 
 test_dependencies = ["Campaign"]
 

erpnext/controllers/accounts_controller.py

@@ -85,7 +85,6 @@ class InvalidQtyError(frappe.ValidationError):
 	"brand",
 	"stock_uom",
 	"is_fixed_asset",
-	"item_tax_rate",
 	"pricing_rules",
 	"weight_per_unit",
 	"weight_uom",
@@ -743,7 +742,6 @@ def set_missing_item_details(self, for_validate=False):
 						args["is_subcontracted"] = self.is_subcontracted
 
 					ret = get_item_details(args, self, for_validate=for_validate, overwrite_warehouse=False)
-
 					for fieldname, value in ret.items():
 						if item.meta.get_field(fieldname) and value is not None:
 							if item.get(fieldname) is None or fieldname in force_item_fields:
@@ -753,7 +751,10 @@ def set_missing_item_details(self, for_validate=False):
 								fieldname
 							):
 								item.set(fieldname, value)
-
+							elif fieldname == "item_tax_rate" and not (
+								self.get("is_return") and self.get("return_against")
+							):
+								item.set(fieldname, value)
 							elif fieldname == "serial_no":
 								# Ensure that serial numbers are matched against Stock UOM
 								item_conversion_factor = item.get("conversion_factor") or 1.0

erpnext/controllers/sales_and_purchase_return.py

@@ -319,6 +319,8 @@ def make_return_doc(doctype: str, source_name: str, target_doc=None, return_agai
 	def set_missing_values(source, target):
 		doc = frappe.get_doc(target)
 		doc.is_return = 1
+		doc.ignore_pricing_rule = 1
+		doc.pricing_rules = []
 		doc.return_against = source.name
 		doc.set_warehouse = ""
 		if doctype == "Sales Invoice" or doctype == "POS Invoice":
@@ -478,6 +480,7 @@ def update_serial_batch_no(source_doc, target_doc, source_parent, item_details,
 
 	def update_item(source_doc, target_doc, source_parent):
 		target_doc.qty = -1 * source_doc.qty
+		target_doc.pricing_rules = None
 		if doctype in ["Purchase Receipt", "Subcontracting Receipt"]:
 			returned_qty_map = get_returned_qty_map_for_row(
 				source_parent.name, source_parent.supplier, source_doc.name, doctype

erpnext/controllers/taxes_and_totals.py

@@ -93,6 +93,9 @@ def calculate_tax_withholding_net_total(self):
 			self.doc.base_tax_withholding_net_total = sum_base_net_amount
 
 	def validate_item_tax_template(self):
+		if self.doc.get("is_return") and self.doc.get("return_against"):
+			return
+
 		for item in self._items:
 			if item.item_code and item.get("item_tax_template"):
 				item_doc = frappe.get_cached_doc("Item", item.item_code)
@@ -242,7 +245,6 @@ def initialize_taxes(self):
 				"tax_fraction_for_current_item",
 				"grand_total_fraction_for_current_item",
 			]
-
 			if tax.charge_type != "Actual" and not (
 				self.discount_amount_applied and self.doc.apply_discount_on == "Grand Total"
 			):

erpnext/public/js/controllers/transaction.js

@@ -1988,6 +1988,8 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 		let item_rates = {};
 		let item_tax_templates = {};
 
+		if (me.frm.doc.is_return && me.frm.doc.return_against) return;
+
 		$.each(this.frm.doc.items || [], function(i, item) {
 			if (item.item_code) {
 				// Use combination of name and item code in case same item is added multiple times