Bug: Fix circular import

[MaferMazu]

Description

When we add from openedx_authz.engine.matcher import is_admin_or_superuser_check in openedx_authz/engine/enforcer.py, we create a circular import issue: enforcer → matcher → api → permissions → enforcer, so when I tried to run ./manage lms load_policy or from openedx_authz.engine.enforcer import AuthzEnforcer in the shell, I get:

from openedx_authz.engine.enforcer import AuthzEnforcer
  File "/openedx/openedx-authz/openedx_authz/engine/enforcer.py", line 25, in <module>
    from openedx_authz.engine.matcher import is_admin_or_superuser_check
  File "/openedx/openedx-authz/openedx_authz/engine/matcher.py", line 5, in <module>
    from openedx_authz.api.data import ContentLibraryData, ScopeData, UserData
  File "/openedx/openedx-authz/openedx_authz/api/__init__.py", line 9, in <module>
    from openedx_authz.api.permissions import *
  File "/openedx/openedx-authz/openedx_authz/api/permissions.py", line 9, in <module>
    from openedx_authz.engine.enforcer import AuthzEnforcer
ImportError: cannot import name 'AuthzEnforcer' from partially initialized module 'openedx_authz.engine.enforcer' (most likely due to a circular import) (/openedx/openedx-authz/openedx_authz/engine/enforcer.py)

How to reproduce the error

Running Load Policy:

1. Use the last version of openedx-authz and try to run ./manage lms load_policy.
2. Get an import error.

Simpler:

1. Enter shell ./manage lms shell
2. Import AuthzEnforcer from openedx_authz.engine.enforcer import AuthzEnforcer

Remotly:

With the #143 I add a test, and without the fix it fail:
You can also see it failing here: https://github.com/eduNEXT/openedx-authz/actions/runs/19317767166/job/55252613927?pr=2

Expected behavior

Be able to run the ./manage lms load_policy withouth problems.

[mariajgrimaldi]

I changed this in this PR: #114 (comment), we could go back to Bryann's solution.

[BryanttV]

@MaferMazu, I'm trying to reproduce the error in my local environment, but I haven’t been able to 🤔 . What version are you using?, I'm using the main branch (v0.15.0)

[MaferMazu]

@mariajgrimaldi, I did't see that comment. But right now, what is merged:

• The load policies calls

from openedx_authz.engine.enforcer import AuthzEnforcer

• Then the engine/enforcer.py calls

from openedx_authz.engine.matcher import is_admin_or_superuser_check

• Then the matcher

from openedx_authz.api.data import ContentLibraryData, ScopeData, UserData

• Then it verify if we import openedx_authz.api before, if not, it enter in __init__

from openedx_authz.api.permissions import *

• And the permission.py calls again the enforcer (circular import)

from openedx_authz.engine.enforcer import AuthzEnforcer

The test doesn't detect them because we mock it or we import the openedx_authz.api before.

But, yes, we can go with the Bryann solution of importing that inside the function.

@BryanttV I was using v0.15.0, but failed from version >v0.13.1.

I added another test on how to reproduce it.

[BryanttV]

@MaferMazu, apart from the test, have we experienced this error at any other time? I remember that it failed when I was implementing the custom matcher, which is why I imported it into the function, but right now I can't reproduce the error.

In any case, if necessary, I also think that the simplest solution would be to put the import back into the function.

[MaferMazu]

@BryanttV, the cases I encountered were those two: running the load_policy command, and simply importing AuthzEnforcer. I am not sure why you can reproduce the first one, that's the one I thought was important to be able to apply the namespace changes, but we still need to be able to use from openedx_authz.engine.enforcer import AuthzEnforcer without depending on importing other things before, that is precisely the test I added.

I have already added the changes to PR #143.