Ensure isinstance is unaffected by sys.setprofile for Concatenate[] and Unpack[] aliases; run PyPy tests under coverage

.github/workflows/ci.yml

@@ -67,13 +67,11 @@ jobs:
           allow-prereleases: true
 
       - name: Install coverage
-        if: ${{ !startsWith(matrix.python-version, 'pypy') }}
         run: |
           # Be wary that this does not install typing_extensions in the future
           pip install coverage
 
       - name: Test typing_extensions with coverage
-        if: ${{ !startsWith(matrix.python-version, 'pypy') }}
         run: |
           # Be wary of running `pip install` here, since it becomes easy for us to
           # accidentally pick up typing_extensions as installed by a dependency
@@ -82,18 +80,9 @@ jobs:
           # Run tests under coverage
           export COVERAGE_FILE=.coverage_${{ matrix.python-version }}
           python -m coverage run -m unittest test_typing_extensions.py
-      - name: Test typing_extensions no coverage on pypy
-        if: ${{ startsWith(matrix.python-version, 'pypy') }}
-        run: |
-          # Be wary of running `pip install` here, since it becomes easy for us to
-          # accidentally pick up typing_extensions as installed by a dependency
-          cd src
-          python --version  # just to make sure we're running the right one
-          python -m unittest test_typing_extensions.py
 
       - name: Archive code coverage results
         id: archive-coverage
-        if: ${{ !startsWith(matrix.python-version, 'pypy') }}
         uses: actions/upload-artifact@v4
         with:
           name: .coverage_${{ matrix.python-version }}

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Unreleased
 
+- Fix incorrect behaviour on Python 3.9 and Python 3.10 that meant that
+  calling `isinstance` with `typing_extensions.Concatenate[...]` or
+  `typing_extensions.Unpack[...]` as the first argument could have a different
+  result in some situations depending on whether or not a profiling function had been
+  set using `sys.setprofile`. This affected both CPython and PyPy implementations.
+  Patch by Brian Schubert.
 - Fix `__init_subclass__()` behavior in the presence of multiple inheritance involving
   an `@deprecated`-decorated base class. Backport of CPython PR
   [#138210](https://github.com/python/cpython/pull/138210) by Brian Schubert.

src/test_typing_extensions.py

@@ -6230,6 +6230,47 @@ def test_is_param_expr(self):
             self.assertTrue(typing._is_param_expr(concat))
             self.assertTrue(typing._is_param_expr(typing_concat))
 
+    def test_isinstance_results_unaffected_by_presence_of_tracing_function(self):
+        # See https://github.com/python/typing_extensions/issues/661
+
+        code = textwrap.dedent(
+            """\
+            import sys, typing
+
+            def trace_call(*args):
+                return trace_call
+
+            def run():
+                sys.modules.pop("typing_extensions", None)
+                from typing_extensions import Concatenate
+                return isinstance(Concatenate[...], typing._GenericAlias)
+            isinstance_result_1 = run()
+            sys.setprofile(trace_call)
+            isinstance_result_2 = run()
+            sys.stdout.write(f"{isinstance_result_1} {isinstance_result_2}")
+            """
+        )
+
+        # Run this in an isolated process or it pollutes the environment
+        # and makes other tests fail:
+        try:
+            proc = subprocess.run(
+                [sys.executable, "-c", code], check=True, capture_output=True, text=True,
+            )
+        except subprocess.CalledProcessError as exc:
+            print("stdout", exc.stdout, sep="\n")
+            print("stderr", exc.stderr, sep="\n")
+            raise
+
+        # Sanity checks that assert the test is working as expected
+        self.assertIsInstance(proc.stdout, str)
+        result1, result2 = proc.stdout.split(" ")
+        self.assertIn(result1, {"True", "False"})
+        self.assertIn(result2, {"True", "False"})
+
+        # The actual test:
+        self.assertEqual(result1, result2)
+
 class TypeGuardTests(BaseTestCase):
     def test_basics(self):
         TypeGuard[int]  # OK
@@ -6652,6 +6693,46 @@ def test_type_var_inheritance(self):
         self.assertFalse(isinstance(Unpack[Ts], TypeVar))
         self.assertFalse(isinstance(Unpack[Ts], typing.TypeVar))
 
+    def test_isinstance_results_unaffected_by_presence_of_tracing_function(self):
+        # See https://github.com/python/typing_extensions/issues/661
+
+        code = textwrap.dedent(
+            """\
+            import sys, typing
+
+            def trace_call(*args):
+                return trace_call
+
+            def run():
+                sys.modules.pop("typing_extensions", None)
+                from typing_extensions import TypeVarTuple, Unpack
+                return isinstance(Unpack[TypeVarTuple("Ts")], typing.TypeVar)
+            isinstance_result_1 = run()
+            sys.setprofile(trace_call)
+            isinstance_result_2 = run()
+            sys.stdout.write(f"{isinstance_result_1} {isinstance_result_2}")
+            """
+        )
+
+        # Run this in an isolated process or it pollutes the environment
+        # and makes other tests fail:
+        try:
+            proc = subprocess.run(
+                [sys.executable, "-c", code], check=True, capture_output=True, text=True,
+            )
+        except subprocess.CalledProcessError as exc:
+            print("stdout", exc.stdout, sep="\n")
+            print("stderr", exc.stderr, sep="\n")
+            raise
+
+        # Sanity checks that assert the test is working as expected
+        self.assertIsInstance(proc.stdout, str)
+        result1, result2 = proc.stdout.split(" ")
+        self.assertIn(result1, {"True", "False"})
+        self.assertIn(result2, {"True", "False"})
+
+        # The actual test:
+        self.assertEqual(result1, result2)
 
 class TypeVarTupleTests(BaseTestCase):
 

src/typing_extensions.py

@@ -1986,7 +1986,9 @@ class _ConcatenateGenericAlias(list):
         __class__ = typing._GenericAlias
 
         def __init__(self, origin, args):
-            super().__init__(args)
+            # Cannot use `super().__init__` here because of the `__class__` assignment
+            # in the class body (https://github.com/python/typing_extensions/issues/661)
+            list.__init__(self, args)
             self.__origin__ = origin
             self.__args__ = args
 
@@ -2545,7 +2547,10 @@ def __typing_is_unpacked_typevartuple__(self):
         def __getitem__(self, args):
             if self.__typing_is_unpacked_typevartuple__:
                 return args
-            return super().__getitem__(args)
+            # Cannot use `super().__getitem__` here because of the `__class__` assignment
+            # in the class body on Python <=3.11
+            # (https://github.com/python/typing_extensions/issues/661)
+            return typing._GenericAlias.__getitem__(self, args)
 
     @_UnpackSpecialForm
     def Unpack(self, parameters):