Support TypedDict field as Dict[str, Any]

changelog.d/237.change.rst

@@ -0,0 +1 @@
+Add `TypedDict` subclass support to fields. These are treated the same as `Dict[str, Any]`.

src/desert/_make.py

@@ -305,11 +305,19 @@ def field_for_schema(
         field = field_for_schema(newtype_supertype, default=default)
 
     # enumerations
-    if type(typ) is enum.EnumMeta:
+    elif type(typ) is enum.EnumMeta:
         import marshmallow_enum
 
         field = marshmallow_enum.EnumField(typ, metadata=metadata)
 
+    # TypedDict
+    # TODO(python3.10) use t.is_typeddict
+    elif isinstance(typ, t._TypedDictMeta):
+        field = marshmallow.fields.Dict(
+            keys=marshmallow.fields.String,
+            values=marshmallow.fields.Raw,
+        )
+
     # Nested dataclasses
     forward_reference = getattr(typ, "__forward_arg__", None)
 

tests/test_make.py

@@ -437,6 +437,26 @@ class A:
     assert_dump_load(schema=schema, loaded=loaded, dumped=dumped)
 
 
+def test_typed_dict(
+    module: DataclassModule,
+    assert_dump_load: AssertLoadDumpProtocol,
+) -> None:
+    """Test dataclasses with basic TypedDict support"""
+
+    class B(t.TypedDict):
+        x: int
+
+    @module.dataclass
+    class A:
+        x: B
+
+    schema = desert.schema_class(A)()
+    dumped = {"x": {"x": 1}}
+    loaded = A(x={"x": 1})
+
+    assert_dump_load(schema=schema, loaded=loaded, dumped=dumped)
+
+
 @pytest.mark.xfail(
     strict=True,
     reason=(
@@ -568,7 +588,6 @@ class A:
     assert schema.loads(schema.dumps(loaded)) == loaded
     assert schema.dump(schema.load(actually_dumped)) == actually_dumped
 
-
 def test_only() -> None:
     """only() extracts the only item in an iterable."""
     assert desert._make.only([1]) == 1