refactor: Made changes suggested by mentor and simplified logic

erpnext/buying/doctype/purchase_order/purchase_order.py

@@ -469,8 +469,7 @@ def on_submit(self):
 		if self.is_against_so():
 			self.update_status_updater()
 
-		is_scpo_from_mr = self.is_subcontracted and all([item.material_request for item in self.items])
-		self.update_prevdoc_status(source_field="fg_item_qty" if is_scpo_from_mr else None)
+		self.update_prevdoc_status()
 		if not self.is_subcontracted or self.is_old_subcontracting_flow:
 			self.update_requested_qty()
 

erpnext/controllers/buying_controller.py

@@ -149,17 +149,7 @@ def set_missing_values(self, for_validate=False):
 		self.set_missing_item_details(for_validate)
 
 	def set_supplier_from_item_default(self):
-		is_scpo_from_mr = False
-		if self.doctype == "Purchase Order":
-			is_scpo_from_mr = all([item.material_request for item in self.items])
-
-		is_default_supplier_passed = bool(frappe.flags.args.default_supplier) if frappe.flags.args else False
-
-		if (
-			self.meta.get_field("supplier") and not self.supplier and is_default_supplier_passed
-			if is_scpo_from_mr
-			else True
-		):
+		if self.meta.get_field("supplier") and not self.supplier:
 			for d in self.get("items"):
 				supplier = frappe.db.get_value(
 					"Item Default", {"parent": d.item_code, "company": self.company}, "default_supplier"

erpnext/controllers/status_updater.py

@@ -171,11 +171,7 @@ class StatusUpdater(Document):
 	Installation Note: Update Installed Qty, Update Percent Qty and Validate over installation
 	"""
 
-	def update_prevdoc_status(self, source_field=None):
-		if source_field:
-			for item in self.status_updater:
-				item.update({"source_field": source_field})
-
+	def update_prevdoc_status(self):
 		self.update_qty()
 		self.validate_qty()
 
@@ -425,6 +421,13 @@ def _update_children(self, args, update_modified):
 			if d.doctype != args["source_dt"]:
 				continue
 
+			if (
+				hasattr(d, "material_request")
+				and frappe.db.get_value("Material Request", d.material_request, "material_request_type")
+				== "Subcontracting"
+			):
+				args.update({"source_field": "fg_item_qty"})
+
 			self._update_modified(args, update_modified)
 
 			# updates qty in the child table

erpnext/stock/doctype/material_request/material_request.py

@@ -398,15 +398,16 @@ def update_item(obj, target, source_parent):
 		if sc_bom := get_subcontracting_boms_for_finished_goods(target.fg_item):
 			target.item_code = sc_bom.service_item
 			target.uom = sc_bom.service_item_uom
-			target.conversion_factor = frappe.db.get_value(
-				"UOM Conversion Detail",
-				{"parent": sc_bom.service_item, "uom": sc_bom.service_item_uom},
-				"conversion_factor",
+			target.conversion_factor = (
+				frappe.db.get_value(
+					"UOM Conversion Detail",
+					{"parent": sc_bom.service_item, "uom": sc_bom.service_item_uom},
+					"conversion_factor",
+				)
+				or 1
 			)
 			target.qty = target.fg_item_qty * sc_bom.conversion_factor
-			target.stock_qty = target.qty / sc_bom.conversion_factor
-		else:
-			target.uom = "Nos"
+			target.stock_qty = target.qty * target.conversion_factor
 
 
 def get_list_context(context=None):
@@ -466,6 +467,22 @@ def select_item(d):
 
 		return qty < d.stock_qty and child_filter
 
+	def generate_field_map():
+		field_map = [
+			["name", "material_request_item"],
+			["parent", "material_request"],
+			["sales_order", "sales_order"],
+			["sales_order_item", "sales_order_item"],
+			["wip_composite_asset", "wip_composite_asset"],
+		]
+
+		if is_subcontracted:
+			field_map.extend([["item_code", "fg_item"], ["qty", "fg_item_qty"]])
+		else:
+			field_map.extend([["uom", "stock_uom"], ["uom", "uom"]])
+
+		return field_map
+
 	doclist = get_mapped_doc(
 		"Material Request",
 		source_name,
@@ -479,21 +496,7 @@ def select_item(d):
 			},
 			"Material Request Item": {
 				"doctype": "Purchase Order Item",
-				"field_map": [
-					item
-					for item in [
-						["name", "material_request_item"],
-						["parent", "material_request"],
-						["qty", "fg_item_qty"] if is_subcontracted else [],
-						["item_code", "fg_item"] if is_subcontracted else [],
-						["uom", "stock_uom"] if not is_subcontracted else [],
-						["uom", "uom"] if not is_subcontracted else [],
-						["sales_order", "sales_order"],
-						["sales_order_item", "sales_order_item"],
-						["wip_composite_asset", "wip_composite_asset"],
-					]
-					if item
-				],  # this list comprehension will remove all empty lists
+				"field_map": generate_field_map(),
 				"field_no_map": ["item_code", "item_name", "qty"] if is_subcontracted else [],
 				"postprocess": update_item,
 				"condition": select_item,