fix(meta): ensure that insert_after is always considered when sorti…

…ng fields (frappe#18682)

* fix(meta): ensure that `insert_after` is always considered when sorting fields

* test: add nosemgrep to comment

Co-authored-by: Dany Roberts <danyrt@wahni.com>
(cherry picked from commit cb7d25a)

frappe/custom/doctype/custom_field/test_custom_field.py

@@ -2,15 +2,14 @@
 # License: MIT. See LICENSE
 
 import frappe
+from frappe.custom.doctype.custom_field.custom_field import create_custom_fields
 from frappe.tests.utils import FrappeTestCase
 
 test_records = frappe.get_test_records("Custom Field")
 
 
 class TestCustomField(FrappeTestCase):
 	def test_create_custom_fields(self):
-		from .custom_field import create_custom_fields
-
 		create_custom_fields(
 			{
 				"Address": [
@@ -37,3 +36,48 @@ def test_create_custom_fields(self):
 		self.assertTrue(frappe.db.exists("Custom Field", "Address-_test_custom_field_1"))
 		self.assertTrue(frappe.db.exists("Custom Field", "Address-_test_custom_field_2"))
 		self.assertTrue(frappe.db.exists("Custom Field", "Contact-_test_custom_field_2"))
+
+	def test_custom_field_sorting(self):
+		try:
+			custom_fields = {
+				"ToDo": [
+					{"fieldname": "a_test_field", "insert_after": "b_test_field"},
+					{"fieldname": "b_test_field", "insert_after": "status"},
+					{"fieldname": "c_test_field", "insert_after": "unknown_custom_field"},
+					{"fieldname": "d_test_field", "insert_after": "status"},
+				]
+			}
+
+			create_custom_fields(custom_fields, ignore_validate=True)
+
+			fields = frappe.get_meta("ToDo", cached=False).fields
+
+			for i, field in enumerate(fields):
+				if field.fieldname == "b_test_field":
+					self.assertEqual(fields[i - 1].fieldname, "status")
+
+				if field.fieldname == "d_test_field":
+					self.assertEqual(fields[i - 1].fieldname, "a_test_field")
+
+			self.assertEqual(fields[-1].fieldname, "c_test_field")
+
+		finally:
+			frappe.db.delete(
+				"Custom Field",
+				{
+					"dt": "ToDo",
+					"fieldname": (
+						"in",
+						(
+							"a_test_field",
+							"b_test_field",
+							"c_test_field",
+							"d_test_field",
+						),
+					),
+				},
+			)
+
+			# undo changes commited by DDL
+			# nosemgrep
+			frappe.db.commit()

frappe/model/meta.py

@@ -140,10 +140,13 @@ def process(self):
 			self.init_field_map()
 			return
 
-		self.add_custom_fields()
+		has_custom_fields = self.add_custom_fields()
 		self.apply_property_setters()
 		self.init_field_map()
-		self.sort_fields()
+
+		if has_custom_fields:
+			self.sort_fields()
+
 		self.get_valid_columns()
 		self.set_custom_permissions()
 		self.add_custom_links_and_actions()
@@ -319,7 +322,7 @@ def get_list_fields(self):
 		return list_fields
 
 	def get_custom_fields(self):
-		return [d for d in self.fields if d.get("is_custom_field")]
+		return [d for d in self.fields if getattr(d, "is_custom_field", False)]
 
 	def get_title_field(self):
 		"""Return the title field of this doctype,
@@ -358,17 +361,20 @@ def add_custom_fields(self):
 		if not frappe.db.table_exists("Custom Field"):
 			return
 
-		custom_fields = frappe.db.sql(
-			"""
-			SELECT * FROM `tabCustom Field`
-			WHERE dt = %s AND docstatus < 2
-		""",
-			(self.name,),
-			as_dict=1,
+		custom_fields = frappe.db.get_values(
+			"Custom Field",
+			filters={"dt": self.name},
+			fieldname="*",
+			as_dict=True,
+			order_by="idx",
 			update={"is_custom_field": 1},
 		)
 
+		if not custom_fields:
+			return
+
 		self.extend("fields", custom_fields)
+		return True
 
 	def apply_property_setters(self):
 		"""
@@ -452,43 +458,33 @@ def init_field_map(self):
 		self._fields = {field.fieldname: field for field in self.fields}
 
 	def sort_fields(self):
-		"""sort on basis of insert_after"""
-		custom_fields = sorted(self.get_custom_fields(), key=lambda df: df.idx)
+		"""Sort custom fields on the basis of insert_after"""
 
-		if custom_fields:
-			newlist = []
+		field_order = []
+		insert_after_map = {}
 
-			# if custom field is at top
-			# insert_after is false
-			for c in list(custom_fields):
-				if not c.insert_after:
-					newlist.append(c)
-					custom_fields.pop(custom_fields.index(c))
+		for field in self.fields:
+			if not getattr(field, "is_custom_field", False):
+				field_order.append(field.fieldname)
 
-			# standard fields
-			newlist += [df for df in self.get("fields") if not df.get("is_custom_field")]
+			elif insert_after := getattr(field, "insert_after", None):
+				insert_after_map.setdefault(insert_after, []).append(field.fieldname)
 
-			newlist_fieldnames = [df.fieldname for df in newlist]
-			for i in range(2):
-				for df in list(custom_fields):
-					if df.insert_after in newlist_fieldnames:
-						cf = custom_fields.pop(custom_fields.index(df))
-						idx = newlist_fieldnames.index(df.insert_after)
-						newlist.insert(idx + 1, cf)
-						newlist_fieldnames.insert(idx + 1, cf.fieldname)
+			else:
+				# if custom field is at the top, insert after is None
+				field_order.insert(0, field.fieldname)
 
-				if not custom_fields:
-					break
+		if insert_after_map:
+			_update_field_order_based_on_insert_after(field_order, insert_after_map)
 
-			# worst case, add remaining custom fields to last
-			if custom_fields:
-				newlist += custom_fields
+		sorted_fields = []
 
-			# renum idx
-			for i, f in enumerate(newlist):
-				f.idx = i + 1
+		for idx, fieldname in enumerate(field_order, 1):
+			field = self._fields[fieldname]
+			field.idx = idx
+			sorted_fields.append(field)
 
-			self.fields = newlist
+		self.fields = sorted_fields
 
 	def set_custom_permissions(self):
 		"""Reset `permissions` with Custom DocPerm if exists"""
@@ -809,3 +805,28 @@ def is_internal(field):
 		frappe.db.sql_ddl(f"ALTER TABLE `tab{doctype}` {columns_to_remove}")
 
 	return DROPPED_COLUMNS
+
+
+def _update_field_order_based_on_insert_after(field_order, insert_after_map):
+	"""Update the field order based on insert_after_map"""
+
+	retry_field_insertion = True
+
+	while retry_field_insertion:
+		retry_field_insertion = False
+
+		for fieldname in list(insert_after_map):
+			if fieldname not in field_order:
+				continue
+
+			custom_field_index = field_order.index(fieldname)
+			for custom_field_name in insert_after_map.pop(fieldname):
+				custom_field_index += 1
+				field_order.insert(custom_field_index, custom_field_name)
+
+			retry_field_insertion = True
+
+	if insert_after_map:
+		# insert_after is an invalid fieldname, add these fields to the end
+		for fields in insert_after_map.values():
+			field_order.extend(fields)