fix: calculate weighted average rate for customer provided items in subcontracting inward order

(cherry picked from commit 37ee560)

Author: ljain112

erpnext/controllers/subcontracting_inward_controller.py

@@ -720,6 +720,7 @@ def update_inward_order_received_items_for_raw_materials_receipt(self):
 				item.db_set("scio_detail", scio_rm.name)
 
 		if data:
+			precision = self.precision("customer_provided_item_cost", "items")
 			result = frappe.get_all(
 				"Subcontracting Inward Order Received Item",
 				filters={
@@ -734,10 +735,17 @@ def update_inward_order_received_items_for_raw_materials_receipt(self):
 			table = frappe.qb.DocType("Subcontracting Inward Order Received Item")
 			case_expr_qty, case_expr_rate = Case(), Case()
 			for d in result:
-				d.received_qty += (
-					data[d.name].transfer_qty if self._action == "submit" else -data[d.name].transfer_qty
+				current_qty = flt(data[d.name].transfer_qty) * (1 if self._action == "submit" else -1)
+				current_rate = flt(data[d.name].rate)
+
+				# Calculate weighted average rate
+				old_total = d.rate * d.received_qty
+				current_total = current_rate * current_qty
+
+				d.received_qty = d.received_qty + current_qty
+				d.rate = (
+					flt((old_total + current_total) / d.received_qty, precision) if d.received_qty else 0.0
 				)
-				d.rate += data[d.name].rate if self._action == "submit" else -data[d.name].rate
 
 				if not d.required_qty and not d.received_qty:
 					deleted_docs.append(d.name)

erpnext/subcontracting/doctype/subcontracting_inward_order/test_subcontracting_inward_order.py

@@ -51,6 +51,49 @@ def test_customer_provided_item_cost_field(self):
 		for item in rm_in.get("items"):
 			self.assertEqual(item.customer_provided_item_cost, 15)
 
+	def test_customer_provided_item_cost_with_multiple_receipts(self):
+		"""
+		Validate that rate is calculated correctly (Weighted Average) when multiple receipts
+		occur for the same SCIO Received Item.
+		"""
+		so, scio = create_so_scio()
+		rm_item = "Basic RM"
+
+		# Receipt 1: 5 Qty @ Unit Cost 10
+		rm_in_1 = frappe.new_doc("Stock Entry").update(scio.make_rm_stock_entry_inward())
+		rm_in_1.items = [item for item in rm_in_1.items if item.item_code == rm_item]
+		rm_in_1.items[0].qty = 5
+		rm_in_1.items[0].basic_rate = 10
+		rm_in_1.items[0].transfer_qty = 5
+		rm_in_1.submit()
+
+		scio.reload()
+		received_item = next(item for item in scio.received_items if item.rm_item_code == rm_item)
+		self.assertEqual(received_item.rate, 10)
+
+		# Receipt 2: 5 Qty @ Unit Cost 20
+		rm_in_2 = frappe.new_doc("Stock Entry").update(scio.make_rm_stock_entry_inward())
+		rm_in_2.items = [item for item in rm_in_2.items if item.item_code == rm_item]
+		rm_in_2.items[0].qty = 5
+		rm_in_2.items[0].basic_rate = 20
+		rm_in_2.items[0].transfer_qty = 5
+		rm_in_2.save()
+		rm_in_2.submit()
+
+		# Check 2: Rate should be Weighted Average
+		# (5 * 10 + 5 * 20) / 10 = 150 / 10 = 15
+		scio.reload()
+		received_item = next(item for item in scio.received_items if item.rm_item_code == rm_item)
+		self.assertEqual(received_item.rate, 15)
+
+		# Cancel Receipt 2: Rate should revert to original
+		# (15 * 10 - 20 * 5) / 5 = 50 / 5 = 10
+		rm_in_2.cancel()
+		scio.reload()
+		received_item = next(item for item in scio.received_items if item.rm_item_code == rm_item)
+		self.assertEqual(received_item.received_qty, 5)
+		self.assertEqual(received_item.rate, 10)
+
 	def test_add_extra_customer_provided_item(self):
 		so, scio = create_so_scio()