Add support for literal enums

marshmallow_dataclass/__init__.py

@@ -40,7 +40,7 @@ class User:
 import threading
 import types
 import warnings
-from enum import EnumMeta
+from enum import Enum, EnumMeta
 from functools import lru_cache, partial
 from typing import (
     Any,
@@ -648,7 +648,22 @@ def field_for_schema(
 
     if typing_inspect.is_literal_type(typ):
         arguments = typing_inspect.get_args(typ)
-        return marshmallow.fields.Raw(
+
+        field_type = marshmallow.fields.Raw
+
+        # If all fields are an enum of the same type, interpret our literal as
+        # an enum instead.
+        if (
+            len(arguments) > 0
+            and isinstance(arguments[0], Enum)
+            and all(type(arguments[0]) == type(arg) for arg in arguments)
+        ):
+            import marshmallow_enum
+
+            metadata["enum"] = type(arguments[0])
+            field_type = marshmallow_enum.EnumField
+
+        return field_type(
             validate=(
                 marshmallow.validate.Equal(arguments[0])
                 if len(arguments) == 1

tests/test_field_for_schema.py

@@ -19,6 +19,12 @@
 )
 
 
+class Color(Enum):
+    RED = 1
+    GREEN = 2
+    BLUE = 3
+
+
 class TestFieldForSchema(unittest.TestCase):
     def assertFieldsEqual(self, a: fields.Field, b: fields.Field):
         self.assertEqual(a.__class__, b.__class__, "field class")
@@ -90,11 +96,6 @@ def test_optional_str(self):
     def test_enum(self):
         import marshmallow_enum
 
-        class Color(Enum):
-            RED: 1
-            GREEN: 2
-            BLUE: 3
-
         self.assertFieldsEqual(
             field_for_schema(Color),
             marshmallow_enum.EnumField(enum=Color, required=True),
@@ -112,6 +113,16 @@ def test_literal_multiple_types(self):
             fields.Raw(required=True, validate=validate.OneOf(("a", 1, 1.23, True))),
         )
 
+    def test_literal_enum(self):
+        import marshmallow_enum
+
+        self.assertFieldsEqual(
+            field_for_schema(Literal[Color.BLUE]),
+            marshmallow_enum.EnumField(
+                required=True, enum=Color, validate=validate.Equal(Color.BLUE)
+            ),
+        )
+
     def test_final(self):
         self.assertFieldsEqual(
             field_for_schema(Final[str]), fields.String(required=True)