Remove support for callable annotations

This approach was unsafe.
See PR #259 for more details

Author: mvanderlee

marshmallow_dataclass/__init__.py

@@ -757,8 +757,6 @@ def _field_for_annotated_type(
             )
             # Support `partial(mf.List, mf.String)`
             or (isinstance(arg, partial) and _is_marshmallow_field(arg.func))
-            # Support `lambda *args, **kwargs: mf.List(mf.String, *args, **kwargs)`
-            or (_is_callable_marshmallow_field(arg))
         ]
         if marshmallow_annotations:
             if len(marshmallow_annotations) > 1:
@@ -1087,18 +1085,6 @@ def _is_marshmallow_field(obj) -> bool:
     ) or isinstance(obj, marshmallow.fields.Field)
 
 
-def _is_callable_marshmallow_field(obj) -> bool:
-    """Checks if the object is a callable and if the callable returns a marshmallow field"""
-    if callable(obj):
-        try:
-            potential_field = obj()
-            return _is_marshmallow_field(potential_field)
-        except Exception:
-            return False
-
-    return False
-
-
 def NewType(
     name: str,
     typ: Type[_U],

tests/test_annotated.py

@@ -66,35 +66,3 @@ class AnnotatedValue:
 
         with self.assertRaises(marshmallow.exceptions.ValidationError):
             schema.load({"emails": "notavalidemail"})
-
-    def test_annotated_callable_field(self) -> None:
-        """
-        NewType allowed us to specify a lambda or partial because there was no type inspection.
-        But with Annotated we do type inspection. While we can't reliably do type inspection on a callable,
-        i.e.: lambda, we can call it and check if it returns a Field.
-        """
-
-        @dataclass
-        class AnnotatedValue:
-            emails: Annotated[
-                List[str],
-                lambda *args, **kwargs: marshmallow.fields.List(
-                    marshmallow.fields.Email, *args, **kwargs
-                ),
-            ] = dataclasses.field(default_factory=lambda: ["default@email.com"])
-
-        schema = AnnotatedValue.Schema()  # type: ignore[attr-defined]
-
-        self.assertEqual(
-            schema.load({}),
-            AnnotatedValue(emails=["default@email.com"]),
-        )
-        self.assertEqual(
-            schema.load({"emails": ["test@test.com"]}),
-            AnnotatedValue(
-                emails=["test@test.com"],
-            ),
-        )
-
-        with self.assertRaises(marshmallow.exceptions.ValidationError):
-            schema.load({"emails": "notavalidemail"})