Add members to ParamSpec stub (#2371)

ChangeLog

@@ -22,6 +22,10 @@ What's New in astroid 3.0.3?
 ============================
 Release date: TBA
 
+* Fix ``no-member`` false positives for ``args`` and ``kwargs`` on ``ParamSpec`` under Python 3.12.
+
+  Closes pylint-dev/pylint#9401
+
 
 What's New in astroid 3.0.2?
 ============================

astroid/brain/brain_typing.py

@@ -437,7 +437,13 @@ def _typing_transform():
     class Generic:
         @classmethod
         def __class_getitem__(cls, item):  return cls
-    class ParamSpec: ...
+    class ParamSpec:
+        @property
+        def args(self):
+            return ParamSpecArgs(self)
+        @property
+        def kwargs(self):
+            return ParamSpecKwargs(self)
     class ParamSpecArgs: ...
     class ParamSpecKwargs: ...
     class TypeAlias: ...

tests/brain/test_brain.py

@@ -678,6 +678,19 @@ def test_typing_no_duplicates_2(self):
         )
         assert len(node.inferred()) == 1
 
+    @test_utils.require_version(minver="3.10")
+    def test_typing_param_spec(self):
+        node = builder.extract_node(
+            """
+        from typing import ParamSpec
+
+        P = ParamSpec("P")
+        """
+        )
+        inferred = next(node.targets[0].infer())
+        assert next(inferred.igetattr("args")) is not None
+        assert next(inferred.igetattr("kwargs")) is not None
+
     def test_collections_generic_alias_slots(self):
         """Test slots for a class which is a subclass of a generic alias type."""
         node = builder.extract_node(