Ability to skip tests or allow errors due to SyntaxError

[anlutro]

I have a test that works with Python 3 type hints. I can easily deal with the typing module not existing in Python < 3.5 by using pytest.importorskip, however, in my test file I'm using type annotations like these:

def f(a: A): return a

This is not valid Syntax in Python 2.7, so the test run errors.

$ pytest
================================ test session starts ================================
platform linux2 -- Python 2.7.13, pytest-3.2.3, py-1.4.34, pluggy-0.4.0
rootdir: /home/andreas/code/allib.py, inifile:
plugins: pythonpath-0.7.1, cov-2.5.1
collected 21 items / 1 errors                                                        

====================================== ERRORS =======================================
_________________________ ERROR collecting tests/di_test.py _________________________
.venv/local/lib/python2.7/site-packages/_pytest/python.py:395: in _importtestmodule
    mod = self.fspath.pyimport(ensuresyspath=importmode)
.venv/local/lib/python2.7/site-packages/py/_path/local.py:662: in pyimport
    __import__(modname)
E     File "/home/andreas/code/allib.py/tests/di_test.py", line 7
E       def f(a: A): return a
E              ^
E   SyntaxError: invalid syntax
!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!!!
============================== 1 error in 0.22 seconds ==============================

As a temporary workaround, I will be moving my stubs with invalid Python 2 syntax to a separate module and deal with the SyntaxError myself, but it would be nice if I could just configure pytest to either skip importing the test at all or skip the error.

The SyntaxError already gets caught here, so it shouldn't be impossible to add some custom behaviour into the except clause.

[nicoddemus]

As a temporary workaround, I will be moving my stubs with invalid Python 2 syntax to a separate module

That's what I would suggest as an workaround.

[The-Compiler]

I don't think there's a way for pytest to even import a module with the SyntaxError. The best thing it could do is offering an option to ignore files where a SyntaxError happened, but I'm not sure that's a good idea. You can already ignore them using a pytest_ignore_collect hook.

[RonnyPfannschmidt]

i also already told on irc that the only way to handle this is to use a extra module and ignore_collect

within a module it is impossible to do at a sane cost
i'm inclined to close this one as the suggested variant is not implementable and the "clean" variant is based on ignore_collect to begin with

[nicoddemus]

i'm inclined to close this one

I agree, the pytest_ignore_collect is a clean way of implementing this customization. @anlutro if you agree, we might add this use case as an example to the docs.

[anlutro]

pytest_ignore_collect works for my use case.

[nicoddemus]

@anlutro thanks for following up. I'm closing this, but if you would like to contribute an example to the docs it would be very welcome. 👍