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

[brianschubert]

Fixes #661

The same kind of workaround as used in #407 seems to work for this case as well. Avoiding the super() calls prevents __class__ from being removed from <type>.__dict__ when a profiling function has been set.

Now the PyPy tests can be run under coverage along with the other tests.

[brianschubert]

Curiously, if the trace function accesses f_locals, e.g.

def trace_call(frame, event, arg):
    frame.f_locals
    return trace_call

then the test fails on Python 3.12.0 (and only this version) with this odd error:

 /home/runner/work/typing_extensions/typing_extensions/src/typing_extensions.py:4303: RuntimeWarning: assigning None to unbound local 'name'
  {name: getattr(typing, name) for name in _typing_names if hasattr(typing, name)}
Traceback (most recent call last):
  File "<string>", line 13, in <module>
  File "<string>", line 9, in run
  File "/home/runner/work/typing_extensions/typing_extensions/src/typing_extensions.py", line 4303, in <module>
    {name: getattr(typing, name) for name in _typing_names if hasattr(typing, name)}
           ^^^^^^^^^^^^^^^^^^^^^
TypeError: attribute name must be string, not 'NoneType'

https://github.com/brianschubert/typing_extensions/actions/runs/17386017836/job/49352484071?pr=5

Note that it only fails on the 3.12.0 tests, not the 3.12 tests (which pass).

The same is true for the existing test in ParamSpecTests that these tests were based on.

[AlexWaygood]

Thank you! I'm... sort-of surprised these work on CPython on Python 3.9, given that we know that this __class__ assignment also does funny things to super() calls on older versions of Python. Or do these new tests fail on older versions of CPython on main too?

[brianschubert]

I'm... sort-of surprised these work on CPython on Python 3.9 [...] Or do these new tests fail on older versions of CPython on main too?

Hmm, actually these tests do fail on older CPython versions:

$ git switch main
$ git restore -s gh-661-pypy-isinstance ./src/test_typing_extensions.py
$ uv run --python cpython3.9 -m unittest ./src/test_typing_extensions.py
........................................................s....sF.s.....s............................s..........s....s..............s.................s..............s................s.....................s........s........s.......................s.....................s....ss.s......s...................................................................................s...................sssssssss....s.............ss.......s.....s.............................s.s...ss...s....................................ss....................s.....s.s..................sFs...s.
======================================================================
FAIL: test_isinstance_results_unaffected_by_presence_of_tracing_function (src.test_typing_extensions.ConcatenateTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/brian/Projects/open-contrib/typing_extensions/src/test_typing_extensions.py", line 6253, in test_isinstance_results_unaffected_by_presence_of_tracing_function
    self.assertEqual(result1, result2)
AssertionError: 'True' != 'False'
- True
+ False


======================================================================
FAIL: test_isinstance_results_unaffected_by_presence_of_tracing_function (src.test_typing_extensions.UnpackTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/brian/Projects/open-contrib/typing_extensions/src/test_typing_extensions.py", line 6716, in test_isinstance_results_unaffected_by_presence_of_tracing_function
    self.assertEqual(result1, result2)
AssertionError: 'True' != 'False'
- True
+ False


----------------------------------------------------------------------
Ran 560 tests in 0.281s

FAILED (failures=2, skipped=48)

Which is perplexing, since the __class__ disappearance behavior doesn't reproduce on older versions when running coverage:

$ uv run --python pypy3.9 -w 'coverage[toml]' coverage run /dev/stdin <<EOF
from typing_extensions import Concatenate
C = Concatenate[...]
print(type(C).__dict__.get("__class__"))
EOF
None

$ uv run --python cpython3.9 -w 'coverage[toml]' coverage run /dev/stdin <<EOF
from typing_extensions import Concatenate
C = Concatenate[...]
print(type(C).__dict__.get("__class__"))
EOF
<class 'typing._GenericAlias'>

[AlexWaygood]

Hmm, actually these tests do fail on older CPython versions:

That makes me feel more confident in merging this -- it demonstrates that it's another occurrence of a pre-existing problem that we already knew about!

The fact that we can only repro it with the minimal repro, not with the coverage run, suggests that coverage might have slightly different code paths depending on whether it's being run on PyPy or CPython. That wouldn't surprise me at all, given that coverage uses a C extension.

[AlexWaygood]

Thank you!