Add support for PEP 695 aliases

README.md

@@ -1815,8 +1815,9 @@ assert a1_dict == a2_dict == a3_dict == a4_dict == {"x": my_class_instance}
 
 There are situations where you might want some values of the same type to be
 treated as their own type. You can create new logical types with
-[`NewType`](https://docs.python.org/3/library/typing.html#newtype) or
+[`NewType`](https://docs.python.org/3/library/typing.html#newtype),
 [`Annotated`](https://docs.python.org/3/library/typing.html#typing.Annotated)
+or [`TypeAliasType`](https://docs.python.org/3/library/typing.html#typing.TypeAliasType)
 and register serialization strategies for them:
 
 ```python
@@ -1827,6 +1828,8 @@ from mashumaro import DataClassDictMixin
 SessionID = NewType("SessionID", str)
 AccountID = Annotated[str, "AccountID"]
 
+type DeviceID = str
+
 @dataclass
 class Context(DataClassDictMixin):
     account_sessions: Mapping[AccountID, SessionID]
@@ -1840,6 +1843,10 @@ class Context(DataClassDictMixin):
             SessionID: {
                 "deserialize": lambda x: ...,
                 "serialize": lambda x: ...,
+            },
+            DeviceID: {
+                "deserialize": lambda x: ...,
+                "serialize": lambda x: ...,
             }
         }
 ```

mashumaro/core/meta/helpers.py

@@ -37,6 +37,7 @@
     PY_39_MIN,
     PY_310_MIN,
     PY_311_MIN,
+    PY_312_MIN,
 )
 from mashumaro.dialect import Dialect
 
@@ -85,6 +86,7 @@
     "is_hashable_type",
     "evaluate_forward_ref",
     "get_forward_ref_referencing_globals",
+    "is_type_alias_type",
 ]
 
 
@@ -793,3 +795,10 @@ def get_forward_ref_referencing_globals(
         )
     else:
         return getattr(forward_module, "__dict__", fallback)
+
+
+def is_type_alias_type(typ: Type) -> bool:
+    if PY_312_MIN:
+        return isinstance(typ, typing.TypeAliasType)
+    else:
+        return False

mashumaro/core/meta/types/pack.py

@@ -41,6 +41,7 @@
     is_required,
     is_self,
     is_special_typing_primitive,
+    is_type_alias_type,
     is_type_var,
     is_type_var_any,
     is_type_var_tuple,
@@ -516,6 +517,8 @@ def pack_special_typing_primitive(spec: ValueSpec) -> Optional[Expression]:
             )
             if evaluated is not None:
                 return PackerRegistry.get(spec.copy(type=evaluated))
+        elif is_type_alias_type(spec.type):
+            return PackerRegistry.get(spec.copy(type=spec.type.__value__))
         raise UnserializableDataError(
             f"{spec.type} as a field type is not supported by mashumaro"
         )

mashumaro/core/meta/types/unpack.py

@@ -46,6 +46,7 @@
     is_required,
     is_self,
     is_special_typing_primitive,
+    is_type_alias_type,
     is_type_var,
     is_type_var_any,
     is_type_var_tuple,
@@ -803,6 +804,8 @@ def unpack_special_typing_primitive(spec: ValueSpec) -> Optional[Expression]:
             )
             if evaluated is not None:
                 return UnpackerRegistry.get(spec.copy(type=evaluated))
+        elif is_type_alias_type(spec.type):
+            return UnpackerRegistry.get(spec.copy(type=spec.type.__value__))
         raise UnserializableDataError(
             f"{spec.type} as a field type is not supported by mashumaro"
         )

tests/conftest.py

@@ -1,6 +1,9 @@
 from unittest.mock import patch
 
-from mashumaro.core.const import PY_313_MIN
+from mashumaro.core.const import PY_312_MIN, PY_313_MIN
+
+if not PY_312_MIN:
+    collect_ignore = ["test_pep_695.py"]
 
 if PY_313_MIN:
     collect_ignore = [

tests/test_pep_695.py

@@ -0,0 +1,27 @@
+from dataclasses import dataclass
+from datetime import date
+
+from mashumaro import DataClassDictMixin
+from mashumaro.codecs import BasicDecoder, BasicEncoder
+
+
+def test_type_alias_type_with_dataclass_dict_mixin():
+    type MyDate = date
+
+    @dataclass
+    class MyClass(DataClassDictMixin):
+        x: MyDate
+
+    obj = MyClass(date(2024, 4, 15))
+    assert MyClass.from_dict({"x": "2024-04-15"}) == obj
+    assert obj.to_dict() == {"x": "2024-04-15"}
+
+
+def test_type_alias_type_with_codecs():
+    type MyDate = date
+    decoder = BasicDecoder(MyDate)
+    encoder = BasicEncoder(MyDate)
+
+    obj = date(2024, 4, 15)
+    assert decoder.decode("2024-04-15") == obj
+    assert encoder.encode(obj) == "2024-04-15"