Improve check structure and types

Django core uses warnings and mostly no objects in checks
Adopting the same style for check readability purposes

axes/checks.py

@@ -1,37 +1,36 @@
-from django.core.checks import Error, Tags, register
+from django.core.checks import Tags, Warning, register  # pylint: disable=redefined-builtin
 
 from axes.conf import settings
 
 
 class Messages:
-    CACHE_INVALID = 'invalid cache configuration for settings.AXES_CACHE'
-    MIDDLEWARE_INVALID = 'axes.middleware.AxesMiddleware not in settings.MIDDLEWARE'
-    BACKEND_INVALID = 'axes.backends.AxesBackend not in settings.AUTHENTICATION_BACKENDS'
+    CACHE_INVALID = (
+        "You are using the django-axes cache handler for login attempt tracking."
+        " Your cache configuration is however invalid and will not work correctly with django-axes."
+        " This can leave security holes in your login systems as attempts are not tracked correctly."
+        " Reconfigure settings.AXES_CACHE and settings.CACHES per django-axes configuration documentation."
+    )
+    MIDDLEWARE_INVALID = (
+        "You do not have 'axes.middleware.AxesMiddleware' in your settings.MIDDLEWARE."
+    )
+    BACKEND_INVALID = (
+        "You do not have 'axes.backends.AxesBackend' in your settings.AUTHENTICATION_BACKENDS."
+    )
 
 
 class Hints:
-    CACHE_INVALID = (
-        'django-axes does not work properly with LocMemCache as the cache backend.'
-        ' Please check the django-axes documentation and reconfigure settings.AXES_CACHE.'
-    )
-    MIDDLEWARE_INVALID = (
-        'django-axes does not work properly without axes.middleware.AxesMiddleware in settings.MIDDLEWARE.'
-        ' Please check the django-axes documentation and reconfigure settings.MIDDLEWARE.'
-    )
-    BACKEND_INVALID = (
-        'django-axes does not work properly without axes.backends.AxesBackend in settings.AUTHENTICATION_BACKENDS.'
-        ' Please check the django-axes documentation and reconfigure settings.AUTHENTICATION_BACKENDS.'
-        ' Please note that the backend name was changed from AxesModelBackend to AxesBackend in django-axes version 5.'
-    )
+    CACHE_INVALID = None
+    MIDDLEWARE_INVALID = None
+    BACKEND_INVALID = 'AxesModelBackend was renamed to AxesBackend in django-axes version 5.0.'
 
 
 class Codes:
-    CACHE_INVALID = 'axes.E001'
-    MIDDLEWARE_INVALID = 'axes.E002'
-    BACKEND_INVALID = 'axes.E003'
+    CACHE_INVALID = 'axes.W001'
+    MIDDLEWARE_INVALID = 'axes.W002'
+    BACKEND_INVALID = 'axes.W003'
 
 
-@register(Tags.compatibility, Tags.caches)
+@register(Tags.security, Tags.caches, Tags.compatibility)
 def axes_cache_check(app_configs, **kwargs):  # pylint: disable=unused-argument
     axes_handler = getattr(settings, 'AXES_HANDLER', '')
 
@@ -49,40 +48,37 @@ def axes_cache_check(app_configs, **kwargs):  # pylint: disable=unused-argument
 
     if axes_handler == 'axes.handlers.cache.AxesCacheHandler':
         if axes_cache_backend in axes_cache_backend_incompatible:
-            errors.append(Error(
+            errors.append(Warning(
                 msg=Messages.CACHE_INVALID,
                 hint=Hints.CACHE_INVALID,
-                obj=settings.CACHES,
                 id=Codes.CACHE_INVALID,
             ))
 
     return errors
 
 
-@register(Tags.compatibility)
+@register(Tags.security, Tags.compatibility)
 def axes_middleware_check(app_configs, **kwargs):  # pylint: disable=unused-argument
     errors = []
 
     if 'axes.middleware.AxesMiddleware' not in settings.MIDDLEWARE:
-        errors.append(Error(
+        errors.append(Warning(
             msg=Messages.MIDDLEWARE_INVALID,
             hint=Hints.MIDDLEWARE_INVALID,
-            obj=settings.MIDDLEWARE,
             id=Codes.MIDDLEWARE_INVALID,
         ))
 
     return errors
 
 
-@register(Tags.compatibility)
+@register(Tags.security, Tags.compatibility)
 def axes_backend_check(app_configs, **kwargs):  # pylint: disable=unused-argument
     errors = []
 
     if 'axes.backends.AxesBackend' not in settings.AUTHENTICATION_BACKENDS:
-        errors.append(Error(
+        errors.append(Warning(
             msg=Messages.BACKEND_INVALID,
             hint=Hints.BACKEND_INVALID,
-            obj=settings.AUTHENTICATION_BACKENDS,
             id=Codes.BACKEND_INVALID,
         ))
 

axes/tests/test_checks.py

@@ -1,8 +1,7 @@
-from django.core.checks import run_checks, Error
+from django.core.checks import run_checks, Warning  # pylint: disable=redefined-builtin
 from django.test import override_settings, modify_settings
 
 from axes.checks import Messages, Hints, Codes
-from axes.conf import settings
 from axes.tests.base import AxesTestCase
 
 
@@ -21,10 +20,9 @@ class CacheCheckTestCase(AxesTestCase):
     )
     def test_cache_check_errors(self):
         errors = run_checks()
-        error = Error(
+        error = Warning(
             msg=Messages.CACHE_INVALID,
             hint=Hints.CACHE_INVALID,
-            obj=settings.CACHES,
             id=Codes.CACHE_INVALID,
         )
 
@@ -47,10 +45,9 @@ class MiddlewareCheckTestCase(AxesTestCase):
     )
     def test_cache_check_errors(self):
         errors = run_checks()
-        error = Error(
+        error = Warning(
             msg=Messages.MIDDLEWARE_INVALID,
             hint=Hints.MIDDLEWARE_INVALID,
-            obj=settings.MIDDLEWARE,
             id=Codes.MIDDLEWARE_INVALID,
         )
 
@@ -65,10 +62,9 @@ class BackendCheckTestCase(AxesTestCase):
     )
     def test_cache_check_errors(self):
         errors = run_checks()
-        error = Error(
+        error = Warning(
             msg=Messages.BACKEND_INVALID,
             hint=Hints.BACKEND_INVALID,
-            obj=settings.AUTHENTICATION_BACKENDS,
             id=Codes.BACKEND_INVALID,
         )