fix: Isolate default user permissions

Nikhi00718 · Nikhi00718 · commit c1cd49b9ac65 · 2026-08-12T17:27:03.000+05:30
Signed-off-by: NIKHIL &lt;atnikhil06@gmail.com&gt;
diff --git a/sdk/python/feast/permissions/user.py b/sdk/python/feast/permissions/user.py
@@ -13,14 +13,14 @@ class User:
     def __init__(
         self,
         username: str,
-        roles: list[str] = [],
-        groups: list[str] = [],
-        namespaces: list[str] = [],
+        roles: Optional[list[str]] = None,
+        groups: Optional[list[str]] = None,
+        namespaces: Optional[list[str]] = None,
     ):
         self._username = username
-        self._roles = roles
-        self._groups = groups
-        self._namespaces = namespaces
+        self._roles = roles if roles is not None else []
+        self._groups = groups if groups is not None else []
+        self._namespaces = namespaces if namespaces is not None else []
 
     @property
     def username(self):
diff --git a/sdk/python/tests/unit/permissions/test_user.py b/sdk/python/tests/unit/permissions/test_user.py
@@ -32,3 +32,16 @@ def test_user_has_matching_role(users, username, roles, result):
     assertpy.assert_that(user.has_matching_role(requested_roles=roles)).is_equal_to(
         result
     )
+
+
+def test_users_have_independent_default_permissions():
+    first_user = User("first")
+    second_user = User("second")
+
+    first_user.roles.append("reader")
+    first_user.groups.append("analytics")
+    first_user.namespaces.append("production")
+
+    assert second_user.roles == []
+    assert second_user.groups == []
+    assert second_user.namespaces == []
