[Backport maintenance/2.15.x] Fix a crash when inferring a typing.TypeVar call. (#2254)

* Fix a crash when inferring a `typing.TypeVar` call. (#2239)

Closes pylint-dev/pylint#8802

(cherry picked from commit 89dfb48)

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---------

Co-authored-by: Mark Byrne <31762852+mbyrnepr2@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

ChangeLog

@@ -18,6 +18,15 @@ Release date: TBA
 
 
 
+What's New in astroid 2.15.7?
+=============================
+Release date: 2023-07-08
+
+* Fix a crash when inferring a ``typing.TypeVar`` call.
+
+  Closes pylint-dev/pylint#8802
+
+
 What's New in astroid 2.15.6?
 =============================
 Release date: 2023-07-08

astroid/brain/brain_typing.py

@@ -121,7 +121,9 @@ def looks_like_typing_typevar_or_newtype(node) -> bool:
     return False
 
 
-def infer_typing_typevar_or_newtype(node, context_itton=None):
+def infer_typing_typevar_or_newtype(
+    node: Call, context_itton: context.InferenceContext | None = None
+) -> Iterator[ClassDef]:
     """Infer a typing.TypeVar(...) or typing.NewType(...) call."""
     try:
         func = next(node.func.infer(context=context_itton))
@@ -137,7 +139,14 @@ def infer_typing_typevar_or_newtype(node, context_itton=None):
         raise UseInferenceDefault
 
     typename = node.args[0].as_string().strip("'")
-    node = extract_node(TYPING_TYPE_TEMPLATE.format(typename))
+    node = ClassDef(
+        name=typename,
+        lineno=node.lineno,
+        col_offset=node.col_offset,
+        parent=node.parent,
+        end_lineno=node.end_lineno,
+        end_col_offset=node.end_col_offset,
+    )
     return node.infer(context=context_itton)
 
 

tests/brain/test_typing.py

@@ -0,0 +1,27 @@
+# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
+# For details: https://github.com/PyCQA/astroid/blob/main/LICENSE
+# Copyright (c) https://github.com/PyCQA/astroid/blob/main/CONTRIBUTORS.txt
+# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
+# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
+# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt
+
+from astroid import builder, nodes
+
+
+def test_infer_typevar() -> None:
+    """
+    Regression test for: https://github.com/pylint-dev/pylint/issues/8802
+
+    Test that an inferred `typing.TypeVar()` call produces a `nodes.ClassDef`
+    node.
+    """
+    assign_node = builder.extract_node(
+        """
+    from typing import TypeVar
+    MyType = TypeVar('My.Type')
+    """
+    )
+    call = assign_node.value
+    inferred = next(call.infer())
+    assert isinstance(inferred, nodes.ClassDef)
+    assert inferred.name == "My.Type"