Avoid recursion when a model instance has multiple deferred audit fields

field_audit/field_audit.py

@@ -62,6 +62,7 @@ def wrapper(cls):
         cls.__init__ = _decorate_init(cls.__init__)
         cls.save = _decorate_db_write(cls.save)
         cls.delete = _decorate_db_write(cls.delete)
+        cls.refresh_from_db = _decorate_refresh_from_db(cls.refresh_from_db)
         _audited_models[cls] = get_fqcn(cls) if class_path is None else class_path  # noqa: E501
         return cls
     if not field_names:
@@ -136,6 +137,23 @@ def wrapper(self, *args, **kw):
     return wrapper
 
 
+def _decorate_refresh_from_db(func):
+    """Decorates the "refresh from db" method on Model subclasses. This is
+    necessary to ensure that all audited fields are included in the refresh
+    to avoid recursively calling the refresh for deferred fields.
+
+    :param func: the "refresh from db" method to decorate
+    """
+    @wraps(func)
+    def wrapper(self, using=None, fields=None, **kwargs):
+        if fields is not None:
+            fields = set(fields) | set(AuditEvent.field_names(self))
+        func(self, using, fields, **kwargs)
+
+    from .models import AuditEvent
+    return wrapper
+
+
 def get_audited_models():
     return _audited_models.copy()
 

tests/test_models.py

@@ -4,6 +4,7 @@
 from unittest.mock import ANY, Mock, patch
 
 import django
+from django.apps import apps
 from django.conf import settings
 from django.db import connection, models, transaction
 from django.db.models import Case, When, Value
@@ -33,7 +34,6 @@
     MakeAuditEventFromValuesException,
 )
 from .mocks import NoopAtomicTransaction
-
 from .models import (
     Aerodrome,
     Aircraft,
@@ -376,6 +376,11 @@ class FlyByTailNumber(models.Model):
                 to_field="tail_number",
             )
 
+        def cleanup_flyby():
+            del apps.all_models["tests"]["flybytailnumber"]
+            apps.clear_cache()
+
+        self.addCleanup(cleanup_flyby)
         flyby = FlyByTailNumber(aircraft=Aircraft(tail_number="CGXII"))
         self.assertEqual("CGXII", AuditEvent.get_field_value(flyby, "aircraft"))
 
@@ -1216,6 +1221,15 @@ def test_delete_audit_action_ignore_calls_super(self):
             queryset.delete(audit_action=AuditAction.IGNORE)
             super_meth.assert_called()
 
+    def test_delete_does_not_cause_recursion_error(self):
+        aircraft = Aircraft.objects.create()
+        object_pk = aircraft.id
+        aircraft = Aircraft.objects.defer("tail_number", "make_model").get(id=object_pk)  # noqa: E501
+        aircraft.delete()
+        event = AuditEvent.objects.last()
+        assert event.is_delete is True
+        assert event.object_pk == object_pk
+
 
 class TestAuditEventBootstrapping(TestCase):