refactor: reliably detect the model attribute cardinality

canaille/backends/ldap/ldapobject.py

@@ -1,4 +1,5 @@
 import itertools
+import typing
 from collections.abc import Iterable
 
 import ldap.dn
@@ -174,7 +175,7 @@ class LDAPObject(Model, metaclass=LDAPObjectMetaclass):
         if ldap_name == "dn":
             return self.dn_for(self.rdn_value)
 
-        python_single_value = "List" not in str(self.attributes[name])
+        python_single_value = typing.get_origin(self.attributes[name]) is not list
         ldap_value = self.get_ldap_attribute(ldap_name)
         return cardinalize_attribute(python_single_value, ldap_value)
 

canaille/backends/memory/models.py

@@ -1,5 +1,6 @@
 import copy
 import datetime
+import typing
 import uuid
 
 from flask import current_app
@@ -196,7 +197,7 @@ class MemoryModel(Model):
                 ]
                 values = [value for value in values if value]
 
-            unique_attribute = "List" not in str(self.attributes[name])
+            unique_attribute = typing.get_origin(self.attributes[name]) is not list
             if unique_attribute:
                 return values[0] if values else None
             else:

canaille/backends/sql/models.py

@@ -1,4 +1,5 @@
 import datetime
+import typing
 import uuid
 from typing import List
 
@@ -72,7 +73,10 @@ class SqlAlchemyModel(Model):
         if isinstance(value, list):
             return or_(cls.attribute_filter(name, v) for v in value)
 
-        multiple = "List" in str(cls.attributes[name])
+        # extract the sqlalchemy.orm.Mapped type
+        attribute_type = typing.get_args(cls.attributes[name])[0]
+        multiple = typing.get_origin(attribute_type) is list
+
         if multiple:
             return getattr(cls, name).contains(value)
 
@@ -203,7 +207,7 @@ class User(canaille.core.models.User, Base, SqlAlchemyModel):
             return all(
                 self.normalize_filter_value(attribute, value)
                 in getattr(self, attribute, [])
-                if "List" in str(self.attributes[attribute])
+                if typing.get_origin(self.attributes[attribute]) is list
                 else self.normalize_filter_value(attribute, value)
                 == getattr(self, attribute, None)
                 for attribute, value in filter.items()