should_never_reach_here for particular test case when parametrized test has unmatched brackets or parenthesis

[ericmclachlan]

Environment data

• VS Code version: 1.62.0-insider
• Extension version (available under the Extensions sidebar): Python v2021.10.1317843341
• OS and version: Windows_NT x64 10.0.19043
• Python version (& distribution if applicable, e.g. Anaconda): 3.8.0
• Type of virtual environment used: N/A
• Value of the python.languageServer setting: Pylance

Expected behaviour

Non-fatal test discovery.

Actual behaviour

Runtime error causes test discovery to fail.

Steps to reproduce:

@pytest.mark.parametrize("test_input,expected",
    [
		# Some tests,
        ("spaces](www", "spaces](www"),
		# Some other tests,
    ]
)
def test_remove_markdown_links(test_input, expected):
    # My implementation

Commenting out the above test case removes the symptoms of the bug.

Logs

Details

The Python extension has run into an unexpected situation
while processing a pytest node during test discovery.  Please
Please open an issue at:
  https://github.com/microsoft/vscode-python/issues
and paste the following output there.

nodeid: ./deployment/tests/test_text_helper.py::test_remove_markdown_links[spaces](www-spaces](www]

traceback:
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/__main__.py", line 100, in main
    parents, result = run(toolargs, **subargs)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 30, in discover
    ec = _pytest_main(pytestargs, [_plugin])
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/config/__init__.py", line 162, in main
    ret: Union[ExitCode, int] = config.hook.pytest_cmdline_main(
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/hooks.py", line 286, in __call__
    return self._hookexec(self, self.get_hookimpls(), kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 93, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 84, in <lambda>
    self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/callers.py", line 187, in _multicall
    res = hook_impl.function(*args)
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/main.py", line 316, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/main.py", line 269, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/main.py", line 322, in _main
    config.hook.pytest_collection(session=session)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/hooks.py", line 286, in __call__
    return self._hookexec(self, self.get_hookimpls(), kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 93, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 84, in <lambda>
    self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/callers.py", line 187, in _multicall
    res = hook_impl.function(*args)
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/main.py", line 333, in pytest_collection
    session.perform_collect()
  File "/home/eric/.local/lib/python3.8/site-packages/_pytest/main.py", line 641, in perform_collect
    hook.pytest_collection_finish(session=self)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/hooks.py", line 286, in __call__
    return self._hookexec(self, self.get_hookimpls(), kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 93, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/manager.py", line 84, in <lambda>
    self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
  File "/home/eric/.local/lib/python3.8/site-packages/pluggy/callers.py", line 187, in _multicall
    res = hook_impl.function(*args)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 107, in pytest_collection_finish
    test, parents = self.parse_item(item)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 77, in parse_item
    return parse_item(item)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 161, in parse_item
    (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 144, in <lambda>
    _parse_node_id=(lambda *a: _parse_node_id(*a)),
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 382, in _parse_node_id
    testid, name, kind = next(nodes)
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 479, in _iter_nodes
    raise should_never_reach_here(
  File "/home/eric/.vscode-server/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 132, in should_never_reach_here
    traceback.print_stack()

[SteggyLeggy]

Same issue here, just started happening for me with an existing project using this parametrize decorator.

@pytest.mark.parametrize("invalid_char", [punct for punct in string.punctuation if punct not in "-_"])

Have recreated in a new folder, using a much simpler test case

import pytest

@pytest.mark.parametrize("invalid_char", ["]"])
def test_pytest_fixture(invalid_char):
    assert invalid_char == "]"

Like I said test discovery was working last week, and I haven't updated pytest since then. Looking at the code in _find_left_bracket in _pytest_item.py it looks like it would of never been able to handle a parameter that contains a single ] so I've no idea why it suddenly stopped work (or how it was working ok before).

The Python extension has run into an unexpected situation
while processing a pytest node during test discovery.  Please
Please open an issue at:
  https://github.com/microsoft/vscode-python/issues
and paste the following output there.

nodeid: ./test_py.py::test_pytest_fixture[]]

traceback:
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/__main__.py", line 100, in main
    parents, result = run(toolargs, **subargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 30, in discover
    ec = _pytest_main(pytestargs, [_plugin])
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/config/__init__.py", line 162, in main
    ret: Union[ExitCode, int] = config.hook.pytest_cmdline_main(
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 316, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 269, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 322, in _main
    config.hook.pytest_collection(session=session)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 333, in pytest_collection
    session.perform_collect()
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 637, in perform_collect
    hook.pytest_collection_modifyitems(
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 92, in pytest_collection_modifyitems
    test, parents = self.parse_item(item)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 77, in parse_item
    return parse_item(item)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 161, in parse_item
    (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 144, in <lambda>
    _parse_node_id=(lambda *a: _parse_node_id(*a)),
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 382, in _parse_node_id
    testid, name, kind = next(nodes)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 479, in _iter_nodes
    raise should_never_reach_here(
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 132, in should_never_reach_here
    traceback.print_stack()
collected 1 item

<Module test_py.py>
  <Function test_pytest_fixture[]]>
The Python extension has run into an unexpected situation
while processing a pytest node during test discovery.  Please
Please open an issue at:
  https://github.com/microsoft/vscode-python/issues
and paste the following output there.

nodeid: ./test_py.py::test_pytest_fixture[]]

traceback:
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/__main__.py", line 100, in main
    parents, result = run(toolargs, **subargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 30, in discover
    ec = _pytest_main(pytestargs, [_plugin])
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/config/__init__.py", line 162, in main
    ret: Union[ExitCode, int] = config.hook.pytest_cmdline_main(
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 316, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 269, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 322, in _main
    config.hook.pytest_collection(session=session)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 333, in pytest_collection
    session.perform_collect()
  File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 641, in perform_collect
    hook.pytest_collection_finish(session=self)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
  File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 107, in pytest_collection_finish
    test, parents = self.parse_item(item)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 77, in parse_item
    return parse_item(item)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 161, in parse_item
    (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 144, in <lambda>
    _parse_node_id=(lambda *a: _parse_node_id(*a)),
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 382, in _parse_node_id
    testid, name, kind = next(nodes)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 479, in _iter_nodes
    raise should_never_reach_here(
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 132, in should_never_reach_here
    traceback.print_stack()
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 637, in perform_collect
INTERNALERROR>     hook.pytest_collection_modifyitems(
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 60, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_result.py", line 60, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 92, in pytest_collection_modifyitems
INTERNALERROR>     test, parents = self.parse_item(item)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 77, in parse_item
INTERNALERROR>     return parse_item(item)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 161, in parse_item
INTERNALERROR>     (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 144, in <lambda>
INTERNALERROR>     _parse_node_id=(lambda *a: _parse_node_id(*a)),
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 382, in _parse_node_id
INTERNALERROR>     testid, name, kind = next(nodes)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 479, in _iter_nodes
INTERNALERROR>     raise should_never_reach_here(
INTERNALERROR> NotImplementedError: Unexpected pytest node (see printed output).
INTERNALERROR> 
INTERNALERROR> During handling of the above exception, another exception occurred:
INTERNALERROR> 
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 269, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 322, in _main
INTERNALERROR>     config.hook.pytest_collection(session=session)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 60, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_result.py", line 60, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 333, in pytest_collection
INTERNALERROR>     session.perform_collect()
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/_pytest/main.py", line 641, in perform_collect
INTERNALERROR>     hook.pytest_collection_finish(session=self)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_hooks.py", line 265, in __call__
INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_manager.py", line 80, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 60, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_result.py", line 60, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "/home/steve2/.local/lib/python3.8/site-packages/pluggy/_callers.py", line 39, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 107, in pytest_collection_finish
INTERNALERROR>     test, parents = self.parse_item(item)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 77, in parse_item
INTERNALERROR>     return parse_item(item)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 161, in parse_item
INTERNALERROR>     (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 144, in <lambda>
INTERNALERROR>     _parse_node_id=(lambda *a: _parse_node_id(*a)),
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 382, in _parse_node_id
INTERNALERROR>     testid, name, kind = next(nodes)
INTERNALERROR>   File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py", line 479, in _iter_nodes
INTERNALERROR>     raise should_never_reach_here(
INTERNALERROR> NotImplementedError: Unexpected pytest node (see printed output).

========================== 1 test collected in 0.00s ===========================

Traceback (most recent call last):
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/__main__.py", line 100, in main
    parents, result = run(toolargs, **subargs)
  File "/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 44, in discover
    raise Exception("pytest discovery failed (exit code {})".format(ec))
Exception: pytest discovery failed (exit code 3)

	at ChildProcess.<anonymous> (/home/steve2/.vscode/extensions/ms-python.python-2021.10.1317843341/out/client/extension.js:9:358475)
	at Object.onceWrapper (events.js:422:26)
	at ChildProcess.emit (events.js:315:20)
	at maybeClose (internal/child_process.js:1048:16)
	at Process.ChildProcess._handle.onexit (internal/child_process.js:288:5)]

EDIT:
Just downgraded to version 2021.9.1246542782 of ms-python.python (I had to download the vsix file and install via the command line) but that has fixed the issue so far.

[mjpieters]

The relevant commit is a68f98f, which is PR #17357.

[mjpieters]

This unfortunately caused a lot of breakage in projects that have an 'unbalanced' ] character in a parameter. The assumption that brackets are always balanced is not correct here, I fear!

Instead, shouldn't the code not just use the provided Node and Function interfaces to 'parse' the name? I know that currently _parse_node_id() is not passed the original item, only item.nodeid, but item has enough information to avoid this whole issue.

E.g., given:

$ pwd
/tmp/mvce
$ cat 'tests/folder-[2]/test_foo.py'
import pytest

@pytest.mark.parametrize("bar", [("]",)])
def test_foo(bar):
    pass
$ python -m pdb ~/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/run_adapter.py discover pytest --no-hide-stdio
# ... PDB session started ...

then when I inspect item inside testing_tools/adapter/pytest/_pytest_item.py:parse_item() you can see it has all the information that _parse_node_id() tries to extract as rich Python object data:

(Pdb) item.nodeid
'tests/folder-[2]/test_foo.py::test_foo[]]'
(Pdb) item.name  # Node API
'test_foo[]]'
(Pdb) item.originalname  # Function API
'test_foo'
(Pdb) item.fspath
local('/private/tmp/mcve/tests/folder-[2]/test_foo.py')
(Pdb) item.fspath.parts()
[local('/'), local('/private'), local('/private/tmp'), local('/private/tmp/mcve'), local('/private/tmp/mcve/tests'), local('/private/tmp/mcve/tests/folder-[2]'), local('/private/tmp/mcve/tests/folder-[2]/test_foo.py')]

I also note that there is also a helpful _pytest.nodes.iterparentnodeids() function:

(Pdb) from _pytest.nodes import iterparentnodeids
(Pdb) print(iterparentnodeids.__doc__)
Return the parent node IDs of a given node ID, inclusive.

    For the node ID

        "testing/code/test_excinfo.py::TestFormattedExcinfo::test_repr_source"

    the result would be

        ""
        "testing"
        "testing/code"
        "testing/code/test_excinfo.py"
        "testing/code/test_excinfo.py::TestFormattedExcinfo"
        "testing/code/test_excinfo.py::TestFormattedExcinfo::test_repr_source"

    Note that :: parts are only considered at the last / component.

(Pdb) pp list(iterparentnodeids(item.nodeid))
['',
 'tests',
 'tests/folder-[2]',
 'tests/folder-[2]/test_foo.py',
 'tests/folder-[2]/test_foo.py::test_foo[]]']

If the expected output for _iter_nodes is:

[('./tests/folder-[2]/test_foo.py::test_foo[]]', '[]]', 'subtest'),
 ('./tests/folder-[2]/test_foo.py::test_foo', 'test_foo', 'function'),
 ('./tests/folder-[2]/test_foo.py', 'test_foo.py', 'file'),
 ('./tests/folder-[2]', 'folder-[2]', 'folder'),
 ('./tests', 'tests', 'folder'),
 ('.', None, 'folder')]

then using .nodeid alone is going to make this way, way too hard. Instead, the first 2 values can already nicely approximated with:

(Pdb) f'{item.parent.nodeid}::{item.originalname}', item.name[len(item.originalname):], 'subtest'
('tests/folder-[2]/test_foo.py::test_foo', '[]]', 'subtest')
(Pdb) item.parent.nodeid, item.originalname, 'function'
('tests/folder-[2]/test_foo.py', 'test_foo', 'function')

Then, perhaps use item.iterchain()[0].fspath as the basis for constructing the remaining elements from the item.fspath.parts() list (see the py.path documentation for the LocalPath() class API).

[mjpieters]

I fixed this locally by replacing lines 161-163 in testing_tools/adapter/pytest/_pytest_item.py, with:

    if kind == "function" and item.nodeid[-1:] == "]":
        # work around microsoft/vscode-python#17676
        parameterized = item.name[len(item.originalname) :]
        (parentid, parents, fileid, testfunc, _) = _parse_node_id(
            item.nodeid[: -len(parameterized)], kind
        )
        nodeid = f"{parentid}{parameterized}"
        parents = [(parentid, item.originalname, kind), *parents]
    else:
        (nodeid, parents, fileid, testfunc, parameterized) = _parse_node_id(
            item.nodeid, kind
        )

On your local system, that's ~/.vscode/extensions/ms-python.python-2021.10.1317843341/pythonFiles/testing_tools/adapter/pytest/_pytest_item.py

So, if the current item is a function and has been parametrized (sic, pytest's misspelling), then it parses the item without the parameters, to then add back that information based on the parsed result. This avoids having to fully rework the way the rest of the nodeid elements are parsed and normalized.

[karthiknadig]

@mjpieters Can you make a PR with this change?

[mjpieters]

@mjpieters Can you make a PR with this change?

I was thinking of that change as an ugly-ish work-around, not the full solution, to be honest.

I'd be happy to turn it into a PR of course, it's your tech debt to pay later ;-)

[karthiknadig]

@mjpieters We have plans replacing this test adapter entirely, there are several issues with the current test adapter. This will be a temporary solution for this issue.