run python ci tests on prerelease branches and pin ipython to <=8.31.0

[sharon-wang]

Summary

• Python CI tests will now run on prerelease branch PRs starting from prerelease/2025.03
• Python CI tests will run when commits are pushed to prerelease branches
• pins ipython to <=8.31.0 to avoid a test failure occurring in the Python IPyKernel tests on this branch and on the main branch

  FAILED python_files/posit/positron/tests/test_positron_ipkernel.py::test_console_traceback - AttributeError: 'AutoFormattedTB' object has no attribute 'Colors'
  

• pulls in use posit cdn instead of github release asset for download url #6496 to fix up python CI tests on mac

NOTE: This change will need to go into main as well!

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical

^{readme  valid tags}

[sharon-wang]

Hmm, the ipykernel tests are failing even after a rerun with:

====================================================== FAILURES ======================================================
_______________________________________________ test_console_traceback _______________________________________________
shell = <positron.positron_ipkernel.PositronShell object at 0x7f20fdbaad50>
tmp_path = PosixPath('/tmp/pytest-of-runner/pytest-0/test_console_traceback0')
mock_displayhook = <Mock id='139779566843792'>
monkeypatch = <_pytest.monkeypatch.MonkeyPatch object at 0x7f20f5f6ad50>
    def test_console_traceback(
        shell: PositronShell, tmp_path: Path, mock_displayhook: Mock, monkeypatch
    ) -> None:
        # Ensure that we're in console mode.
        monkeypatch.setattr(shell, "session_mode", SessionMode.CONSOLE)
    
        # We follow the approach of IPython's test_ultratb.py, which is to create a temporary module,
        # prepend its parent directory to sys.path, import it, then run a cell that calls a function
        # from it.
    
        # Create a temporary module.
        file = tmp_path / "test_traceback.py"
        file.write_text(code)
    
        # Temporarily add the module to sys.path and call a function from it, which should error.
        with prepended_to_syspath(str(tmp_path)):
            shell.run_cell("import test_traceback; test_traceback.g()")
    
        # NOTE(seem): This is not elegant, but I'm not sure how else to test this than other than to
        # compare the beginning of each frame of the traceback. The escape codes make it particularly
        # challenging.
    
        path = str(alias_home(file))
        uri = file.expanduser().as_uri()
    
        # Define a few OSC8 escape codes for convenience.
        esc = "\x1b"
        osc8 = esc + "]8"
        st = esc + "\\"
    
        # Convenient reference to colors from the active scheme.
>       colors = cast(Any, shell.InteractiveTB.Colors)
E       AttributeError: 'AutoFormattedTB' object has no attribute 'Colors'
python_files/posit/positron/tests/test_positron_ipkernel.py:162: AttributeError

Is the prerelease branch missing a fix for this?

EDIT: this is also failing for branches targeting main

[jonvanausdeln]

LGTM!

[isabelizimm]

without looking into it much, it sort of looks like something in the test requirements got updated and is now breaking. We generally pin all our dependencies, but there's one file that does not: https://github.com/posit-dev/positron/blob/db8f78b2bf2964778b039e8d0e01f02ef70ec3a0/extensions/positron-python/build/test-requirements.txt

update to mention that ipython, which imports AutoFormattedTB had a fresh 9.0.0 release earlier today

[sharon-wang]

without looking into it much, it sort of looks like something in the test requirements got updated and is now breaking. We generally pin all our dependencies, but there's one file that does not: https://github.com/posit-dev/positron/blob/db8f78b2bf2964778b039e8d0e01f02ef70ec3a0/extensions/positron-python/build/test-requirements.txt

update to mention that ipython, which imports AutoFormattedTB had a fresh 9.0.0 release earlier today

Thank you for this tip!! Pinned ipython<=8.31.0 and now the ipykernel tests are all green ✅ 🎉