[Backport maintenance/2.13.x] Fix issues with typing_extensions.TypeVar

ChangeLog

@@ -12,6 +12,8 @@ What's New in astroid 2.13.4?
 =============================
 Release date: TBA
 
+* Fix issues with ``typing_extensions.TypeVar``.
+
 
 
 What's New in astroid 2.13.3?

astroid/brain/brain_namedtuple_enum.py

@@ -40,7 +40,15 @@
     "enum.IntFlag",
 }
 ENUM_QNAME: Final[str] = "enum.Enum"
-TYPING_NAMEDTUPLE_BASENAMES: Final[set[str]] = {"NamedTuple", "typing.NamedTuple"}
+TYPING_NAMEDTUPLE_QUALIFIED: Final = {
+    "typing.NamedTuple",
+    "typing_extensions.NamedTuple",
+}
+TYPING_NAMEDTUPLE_BASENAMES: Final = {
+    "NamedTuple",
+    "typing.NamedTuple",
+    "typing_extensions.NamedTuple",
+}
 
 
 def _infer_first(node, context):
@@ -542,7 +550,7 @@ def infer_typing_namedtuple(
     except (InferenceError, StopIteration) as exc:
         raise UseInferenceDefault from exc
 
-    if func.qname() != "typing.NamedTuple":
+    if func.qname() not in TYPING_NAMEDTUPLE_QUALIFIED:
         raise UseInferenceDefault
 
     if len(node.args) != 2:

astroid/brain/brain_typing.py

@@ -6,6 +6,7 @@
 
 from __future__ import annotations
 
+import sys
 import typing
 from collections.abc import Iterator
 from functools import partial
@@ -34,9 +35,18 @@
 from astroid.nodes.scoped_nodes import ClassDef, FunctionDef
 from astroid.util import Uninferable
 
-TYPING_NAMEDTUPLE_BASENAMES = {"NamedTuple", "typing.NamedTuple"}
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
 TYPING_TYPEVARS = {"TypeVar", "NewType"}
-TYPING_TYPEVARS_QUALIFIED = {"typing.TypeVar", "typing.NewType"}
+TYPING_TYPEVARS_QUALIFIED: Final = {
+    "typing.TypeVar",
+    "typing.NewType",
+    "typing_extensions.TypeVar",
+}
+TYPING_TYPEDDICT_QUALIFIED: Final = {"typing.TypedDict", "typing_extensions.TypedDict"}
 TYPING_TYPE_TEMPLATE = """
 class Meta(type):
     def __getitem__(self, item):
@@ -186,7 +196,7 @@ def _looks_like_typedDict(  # pylint: disable=invalid-name
     node: FunctionDef | ClassDef,
 ) -> bool:
     """Check if node is TypedDict FunctionDef."""
-    return node.qname() in {"typing.TypedDict", "typing_extensions.TypedDict"}
+    return node.qname() in TYPING_TYPEDDICT_QUALIFIED
 
 
 def infer_old_typedDict(  # pylint: disable=invalid-name

requirements_test_brain.txt

@@ -9,3 +9,4 @@ types-python-dateutil
 six
 types-six
 urllib3
+typing_extensions>=4.4.0

tests/unittest_brain.py

@@ -66,6 +66,15 @@
 except ImportError:
     HAS_SIX = False
 
+try:
+    import typing_extensions  # pylint: disable=unused-import
+
+    HAS_TYPING_EXTENSIONS = True
+    HAS_TYPING_EXTENSIONS_TYPEVAR = hasattr(typing_extensions, "TypeVar")
+except ImportError:
+    HAS_TYPING_EXTENSIONS = False
+    HAS_TYPING_EXTENSIONS_TYPEVAR = False
+
 
 def assertEqualMro(klass: ClassDef, expected_mro: list[str]) -> None:
     """Check mro names."""
@@ -2148,6 +2157,29 @@ class A:
         assert inferred.value == 42
 
 
+@pytest.mark.skipif(
+    not HAS_TYPING_EXTENSIONS,
+    reason="These tests require the typing_extensions library",
+)
+class TestTypingExtensions:
+    @staticmethod
+    @pytest.mark.skipif(
+        not HAS_TYPING_EXTENSIONS_TYPEVAR,
+        reason="Need typing_extensions>=4.4.0 to test TypeVar",
+    )
+    def test_typing_extensions_types() -> None:
+        ast_nodes = builder.extract_node(
+            """
+        from typing_extensions import TypeVar
+        TypeVar('MyTypeVar', int, float, complex) #@
+        TypeVar('AnyStr', str, bytes) #@
+        """
+        )
+        for node in ast_nodes:
+            inferred = next(node.infer())
+            assert isinstance(inferred, nodes.ClassDef)
+
+
 class ReBrainTest(unittest.TestCase):
     def test_regex_flags(self) -> None:
         names = [name for name in dir(re) if name.isupper()]