Fix a false negative for too-many-arguments and positional-only and keyword-only arguments

doc/whatsnew/fragments/8667.false_negative

@@ -0,0 +1,3 @@
+Fix a false negative for ``too-many-arguments`` by considering positional-only and keyword-only parameters.
+
+Closes #8667

pylint/checkers/design_analysis.py

@@ -506,7 +506,7 @@ def visit_functiondef(self, node: nodes.FunctionDef) -> None:
         # init branch and returns counters
         self._returns.append(0)
         # check number of arguments
-        args = node.args.args
+        args = node.args.args + node.args.posonlyargs + node.args.kwonlyargs
         ignored_argument_names = self.linter.config.ignored_argument_names
         if args is not None:
             ignored_args_num = 0

pylint/config/argument.py

@@ -229,6 +229,7 @@ class _StoreArgument(_BaseStoreArgument):
     https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument
     """
 
+    # pylint: disable-next=too-many-arguments
     def __init__(
         self,
         *,
@@ -306,6 +307,7 @@ class _DeprecationArgument(_Argument):
     https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument
     """
 
+    # pylint: disable-next=too-many-arguments
     def __init__(
         self,
         *,
@@ -354,6 +356,7 @@ class _ExtendArgument(_DeprecationArgument):
     https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument
     """
 
+    # pylint: disable-next=too-many-arguments
     def __init__(
         self,
         *,
@@ -398,6 +401,7 @@ class _StoreOldNamesArgument(_DeprecationArgument):
     https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument
     """
 
+    # pylint: disable-next=too-many-arguments
     def __init__(
         self,
         *,
@@ -435,6 +439,7 @@ class _StoreNewNamesArgument(_DeprecationArgument):
     https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument
     """
 
+    # pylint: disable-next=too-many-arguments
     def __init__(
         self,
         *,

tests/functional/n/non_ascii_name/non_ascii_name_pos_and_kwonly_function.py

@@ -4,7 +4,7 @@
 This test is 3.8+ as the columns are not correctly identified
 by the ast parser < 3.8
 """
-# pylint: disable=unused-argument
+# pylint: disable=unused-argument,too-many-arguments
 
 
 def name(

tests/functional/t/too/too_many_arguments.py

@@ -30,3 +30,8 @@ def func_call():
     partial_func = partial(root_function, 1, 2, 3)
     partial_func()
     return root_function(1, 2, 3)
+
+
+# +1: [too-many-arguments]
+def name1(param1, param2, param3, /, param4, param5, *args, param6="apple", **kwargs):
+    return param1, param2, param3, param4, param5, param6, args, kwargs

tests/functional/t/too/too_many_arguments.txt

@@ -1 +1,2 @@
 too-many-arguments:3:0:3:19:stupid_function:Too many arguments (9/5):UNDEFINED
+too-many-arguments:36:0:36:9:name1:Too many arguments (6/5):UNDEFINED