.github/workflows/third_party.yml

@@ -343,6 +343,33 @@ jobs:
             --force-dep "typing-extensions @ file://$(pwd)/../typing-extensions-latest" \
             -- -q --nomemory --notimingintensive
 
+
+  litestar:
+    name: litestar tests
+    needs: skip-schedule-on-fork
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+    steps:
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Checkout litestar
+        run: git clone --depth=1 https://github.com/litestar-org/litestar.git || git clone --depth=1 https://github.com/litestar-org/litestar.git
+      - name: Checkout typing_extensions
+        uses: actions/checkout@v4
+        with:
+          path: typing-extensions-latest
+      - name: Install uv
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+      - name: Run litestar tests
+        run: uv run --with=../typing-extensions-latest -- python -m pytest tests/unit/test_typing.py tests/unit/test_dto
+        working-directory: litestar
+
   create-issue-on-failure:
     name: Create an issue if daily tests failed
     runs-on: ubuntu-latest

CHANGELOG.md

@@ -1,3 +1,13 @@
+# Release 4.13.2 (April 10, 2025)
+
+- Fix `TypeError` when taking the union of `typing_extensions.TypeAliasType` and a
+  `typing.TypeAliasType` on Python 3.12 and 3.13.
+  Patch by [Joren Hammudoglu](https://github.com/jorenham).
+- Backport from CPython PR [#132160](https://github.com/python/cpython/pull/132160)
+  to avoid having user arguments shadowed in generated `__new__` by
+  `@typing_extensions.deprecated`.
+  Patch by [Victorien Plot](https://github.com/Viicos).
+
 # Release 4.13.1 (April 3, 2025)
 
 Bugfixes:

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "flit_core.buildapi"
 # Project metadata
 [project]
 name = "typing_extensions"
-version = "4.13.1"
+version = "4.13.2"
 description = "Backported and Experimental Type Hints for Python 3.8+"
 readme = "README.md"
 requires-python = ">=3.8"

src/test_typing_extensions.py

@@ -707,6 +707,25 @@ class Child(Base, Mixin):
         instance = Child(42)
         self.assertEqual(instance.a, 42)
 
+    def test_do_not_shadow_user_arguments(self):
+        new_called = False
+        new_called_cls = None
+
+        @deprecated("MyMeta will go away soon")
+        class MyMeta(type):
+            def __new__(mcs, name, bases, attrs, cls=None):
+                nonlocal new_called, new_called_cls
+                new_called = True
+                new_called_cls = cls
+                return super().__new__(mcs, name, bases, attrs)
+
+        with self.assertWarnsRegex(DeprecationWarning, "MyMeta will go away soon"):
+            class Foo(metaclass=MyMeta, cls='haha'):
+                pass
+
+        self.assertTrue(new_called)
+        self.assertEqual(new_called_cls, 'haha')
+
     def test_existing_init_subclass(self):
         @deprecated("C will go away soon")
         class C:
@@ -7819,6 +7838,10 @@ def test_or(self):
             self.assertEqual(Alias | None, Union[Alias, None])
             self.assertEqual(Alias | (int | str), Union[Alias, int | str])
             self.assertEqual(Alias | list[float], Union[Alias, list[float]])
+
+            if sys.version_info >= (3, 12):
+                Alias2 = typing.TypeAliasType("Alias2", str)
+                self.assertEqual(Alias | Alias2, Union[Alias, Alias2])
         else:
             with self.assertRaises(TypeError):
                 Alias | int

src/typing_extensions.py

@@ -3123,7 +3123,8 @@ def method(self) -> None:
         return arg
 
 
-if hasattr(warnings, "deprecated"):
+# Python 3.13.3+ contains a fix for the wrapped __new__
+if sys.version_info >= (3, 13, 3):
     deprecated = warnings.deprecated
 else:
     _T = typing.TypeVar("_T")
@@ -3203,7 +3204,7 @@ def __call__(self, arg: _T, /) -> _T:
                 original_new = arg.__new__
 
                 @functools.wraps(original_new)
-                def __new__(cls, *args, **kwargs):
+                def __new__(cls, /, *args, **kwargs):
                     if cls is arg:
                         warnings.warn(msg, category=category, stacklevel=stacklevel + 1)
                     if original_new is not object.__new__:
@@ -3827,14 +3828,27 @@ def __ror__(self, other):
     TypeAliasType = typing.TypeAliasType
 # 3.8-3.13
 else:
-    def _is_unionable(obj):
-        """Corresponds to is_unionable() in unionobject.c in CPython."""
-        return obj is None or isinstance(obj, (
-            type,
-            _types.GenericAlias,
-            _types.UnionType,
-            TypeAliasType,
-        ))
+    if sys.version_info >= (3, 12):
+        # 3.12-3.14
+        def _is_unionable(obj):
+            """Corresponds to is_unionable() in unionobject.c in CPython."""
+            return obj is None or isinstance(obj, (
+                type,
+                _types.GenericAlias,
+                _types.UnionType,
+                typing.TypeAliasType,
+                TypeAliasType,
+            ))
+    else:
+        # 3.8-3.11
+        def _is_unionable(obj):
+            """Corresponds to is_unionable() in unionobject.c in CPython."""
+            return obj is None or isinstance(obj, (
+                type,
+                _types.GenericAlias,
+                _types.UnionType,
+                TypeAliasType,
+            ))
 
     if sys.version_info < (3, 10):
         # Copied and pasted from https://github.com/python/cpython/blob/986a4e1b6fcae7fe7a1d0a26aea446107dd58dd2/Objects/genericaliasobject.c#L568-L582,