Merge pull request #438 from acolley-gel/main

Fix frozenset union with prim #437

Author: yukinarit

serde/core.py

@@ -413,7 +413,7 @@ def is_list_instance(obj: Any, typ: Type[Any]) -> bool:
 
 
 def is_set_instance(obj: Any, typ: Type[Any]) -> bool:
-    if not isinstance(obj, set):
+    if not isinstance(obj, (set, frozenset)):
         return False
     if len(obj) == 0 or is_bare_set(typ):
         return True

tests/test_union.py

@@ -2,7 +2,7 @@
 import sys
 from dataclasses import dataclass
 from ipaddress import IPv4Address
-from typing import Dict, Generic, List, NewType, Optional, Tuple, TypeVar, Union
+from typing import Dict, FrozenSet, Generic, List, NewType, Optional, Tuple, TypeVar, Union
 from uuid import UUID
 
 import pytest
@@ -763,3 +763,12 @@ class Bar:
     # untagged tagged
     s = to_json(bar, cls=Untagged(Union[Foo, Bar]))
     assert bar == from_json(Untagged(Union[Foo, Bar]), s)
+
+
+def test_union_frozenset_with_prim():
+    @serde
+    @dataclass
+    class Foo:
+        a: Union[FrozenSet[int], int]
+
+    assert to_dict(Foo(frozenset({1}))) == {"a": {1}}