cannot use pyfakefs and tempfile at the same time

[franklingu]

I am not sure if this is actually an issue or it is something that I do not understand. So I have a module that makes use of tempfile to create temporary directory and manipulate files in the directory. When I test with out pyfakefs, things are OK and tests are OK as well. But I when I load pyfakefs in another test file that will be run before this test file, things will break -- temporary dir will not be created, and writing to files in temprorary dir will fail of course.

I am using Python 3.6.1. Ubuntu 16.04.

A minimal case:

And the output:

(.venv36) jgu@jgu-pc:~/repos/temp % py.test -vv -s tests/test_abc.py
=========================================================================================== test session starts ============================================================================================
platform linux -- Python 3.6.1, pytest-3.4.2, py-1.5.2, pluggy-0.6.0 -- /home/jgu/repos/.venv36/bin/python3.6
cachedir: .pytest_cache
rootdir: /home/jgu/repos/temp, inifile:
plugins: mock-1.7.1, cov-2.5.1, pyfakefs-3.4
collected 1 item                                                                                                                                                                                           

tests/test_abc.py::test_func PASSED

========================================================================================= 1 passed in 0.11 seconds =========================================================================================
(.venv36) jgu@jgu-pc:~/repos/temp % py.test -vv -s                  
=========================================================================================== test session starts ============================================================================================
platform linux -- Python 3.6.1, pytest-3.4.2, py-1.5.2, pluggy-0.6.0 -- /home/jgu/repos/.venv36/bin/python3.6
cachedir: .pytest_cache
rootdir: /home/jgu/repos/temp, inifile:
plugins: mock-1.7.1, cov-2.5.1, pyfakefs-3.4
collected 2 items                                                                                                                                                                                          

tests/test_a.py::test_void PASSED
tests/test_abc.py::test_func FAILED

================================================================================================= FAILURES =================================================================================================
________________________________________________________________________________________________ test_func _________________________________________________________________________________________________

    def func():
        try:
            td = tempfile.TemporaryDirectory()
>           with open(td.name + '/tmp.txt', 'w') as ofile:
E           FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmpoepn6_lx/tmp.txt'

packa/abc.py:7: FileNotFoundError

During handling of the above exception, another exception occurred:

    def test_func():
>       assert abc.func()

tests/test_abc.py:5: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
packa/abc.py:11: in func
    td.cleanup()
../.venv36/lib/python3.6/tempfile.py:811: in cleanup
    _shutil.rmtree(self.name)
../.venv36/lib/python3.6/shutil.py:471: in rmtree
    onerror(os.lstat, path, sys.exc_info())
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

path = '/tmp/tmpoepn6_lx', ignore_errors = False, onerror = <function rmtree.<locals>.onerror at 0x7f221a845bf8>

    def rmtree(path, ignore_errors=False, onerror=None):
        """Recursively delete a directory tree.
    
        If ignore_errors is set, errors are ignored; otherwise, if onerror
        is set, it is called to handle the error with arguments (func,
        path, exc_info) where func is platform and implementation dependent;
        path is the argument to that function that caused it to fail; and
        exc_info is a tuple returned by sys.exc_info().  If ignore_errors
        is false and onerror is None, an exception is raised.
    
        """
        if ignore_errors:
            def onerror(*args):
                pass
        elif onerror is None:
            def onerror(*args):
                raise
        if _use_fd_functions:
            # While the unsafe rmtree works fine on bytes, the fd based does not.
            if isinstance(path, bytes):
                path = os.fsdecode(path)
            # Note: To guard against symlink races, we use the standard
            # lstat()/open()/fstat() trick.
            try:
>               orig_st = os.lstat(path)
E               FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmpoepn6_lx'

../.venv36/lib/python3.6/shutil.py:469: FileNotFoundError
==================================================================================== 1 failed, 1 passed in 0.19 seconds ====================================================================================

[mrbean-bremen]

Could you please test with pyfakefs 3.4.1? There has been a similar issue that has been fixed in this release.

[franklingu]

I just upgraded. tests are OK now. I think can close this issue. Thanks a lot for the help

[mrbean-bremen]

You are welcome!