Fixed incorrect caching that caused throwing exception

dacite/types.py

@@ -16,7 +16,6 @@
 T = TypeVar("T", bound=Any)
 
 
-@cache
 def extract_origin_collection(collection: Type) -> Type:
     try:
         return collection.__extra__
@@ -38,7 +37,6 @@ def extract_optional(optional: Type[Optional[T]]) -> T:
         raise ValueError("can not find not-none value")
 
 
-@cache
 def is_generic(type_: Type) -> bool:
     return hasattr(type_, "__origin__")
 
@@ -140,7 +138,6 @@ def is_instance(value: Any, type_: Type) -> bool:
         return False
 
 
-@cache
 def is_generic_collection(type_: Type) -> bool:
     if not is_generic(type_):
         return False

tests/core/test_subsequent_calls.py

@@ -0,0 +1,21 @@
+from dataclasses import dataclass
+from typing import Optional
+
+from dacite import from_dict, Config
+
+
+def test_from_dict_subsequent_calls_on_optional_type_and_union_none_does_not_raise():
+    @dataclass
+    class OptionalDataclass:
+        text: Optional[str]
+
+    @dataclass
+    class UnionDataclass:
+        text: str | None
+
+    d1 = {"text": None}
+    from_dict(OptionalDataclass, d1)
+
+    d2 = {"text": "abc"}
+    c = Config(cast=[int])
+    from_dict(UnionDataclass, d2, config=c)

tests/test_types.py

@@ -399,3 +399,8 @@ class FakeType:
         _special = True
 
     assert extract_generic(FakeType, defaults) == defaults
+
+
+def test_optional_and_union_none_does_not_pollute_scope_via_caching():
+    is_generic(Optional[str])
+    is_generic_collection(str | None)