AttributeError: type object 'Path' has no attribute '_flavour' - error seen when using Click 8 #600

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1. mrbean-bremen commented on May 17, 2021

   

   mrbean-bremen

   on May 17, 2021

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   Thanks for the report! I had a first look, and I'm not sure yet what to do in this case.

   As pathlib.Path is read in the decorator at load time, it will not be patched, as it is already cached at patch time. Usually, reloading the module in question helps to fix that, but in this case, it doesn't - the click module still holds the unpatched type somewhere. click does a bit of magic here by declaring it's own Path class to be of type pathlib.Path, which may be a problem for pyfakefs.

   I will have a closer look, but cannot promise anything yet.
2. adamtheturtle commented on May 17, 2021

   

   adamtheturtle

   on May 17, 2021

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   @mrbean-bremen - Thanks so much for the quick response! I really appreciate the project and your work on it. Workarounds / anything like that are welcome if any come to mind.
3. mrbean-bremen commented on May 17, 2021

   

   mrbean-bremen

   on May 17, 2021

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   Sorry, didn't get anywhere - I need to have a look at this someday with a fresh eye.
4. adamtheturtle commented on May 17, 2021

   

   adamtheturtle

   on May 17, 2021

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   No need to be sorry!
5. mrbean-bremen commented on May 23, 2021

   

   mrbean-bremen

   on May 23, 2021

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   Ok, now with a fresh brain I can see that I obviously did a mistake last time I checked this. Sorry it took so long, looks like I needed the weekend to clear my head...

   The problem is, as stated above, that the decorator is evaluated at load time, before the patcher had a chance to patch it. The only way to work around this is to reload the module during the test, so that the decorator will be re-evaluated. This assumes that you have the sut and the test in different modules. Here is a version that worked for me:

   pyfakefs_tests/pathlib_click.py

   import pathlib
   import click
   
   @click.command()
   @click.argument('foo', type=click.Path(path_type=pathlib.Path))
   def hello(foo):
       print(foo)

   pyfakefs_tests/test_pathlib_click.py

   from pyfakefs.fake_filesystem_unittest import Patcher
   
   from pyfakefs_tests import pathlib_click
   
   with Patcher(modules_to_reload=[pathlib_click]):
       pathlib_click.hello(['/'])

   Note that in this case it is essential not to do from pyfakefs_tests.pathlib_clock import hello, as in this case you would have the unpatched hello object cached in the test itself. You could import it locally in the test, though:

   from pyfakefs.fake_filesystem_unittest import Patcher
   from pyfakefs_tests import pathlib_click
   
   with Patcher(modules_to_reload=[pathlib_click]):
       from pathlib_click import hello
       hello(['/'])

   Note that these problems are not specific to pyfakefs, but a general problem with patching using unittest or pytest.
6. mrbean-bremen

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   on May 23, 2021
7. adamtheturtle commented on May 23, 2021

   

   adamtheturtle

   on May 23, 2021

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   @mrbean-bremen - No need to apologise, and thank you for your time and thought. I'm happy to work around this and I appreciate your work. I'll leave the choice of whether to close this to you.
8. adamtheturtle

   closed this as completedon May 23, 2021
9. adamtheturtle

   reopened this on May 23, 2021
10. mrbean-bremen commented on May 23, 2021

    

    mrbean-bremen

    on May 23, 2021

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    If the repo maintainer enables discussions, I will convert this into a Q/A discussion issue, as it may help others.
11. mrbean-bremen

    closed this as completedon May 23, 2021
12. pytest-dev

    locked and limited conversation to collaborators on May 23, 2021