Use a ForwardRef object as a result of inspect.signature annotations

mashumaro/core/meta/code/builder.py

@@ -293,7 +293,8 @@ def evaluate_forward_ref(
         typ: typing.ForwardRef,
         owner: typing.Optional[typing.Type],
     ) -> typing.Optional[typing.Type]:
-        if not getattr(typ, "__forward_module__", None) and owner:
+        forward_module = getattr(typ, "__forward_module__", None)
+        if not forward_module and owner:
             # We can't get the module in which ForwardRef's value is defined on
             # Python < 3.10, ForwardRef evaluation might not work properly
             # without this information, so we will consider the namespace of
@@ -304,7 +305,7 @@ def evaluate_forward_ref(
                 self.globals,
             )
         else:
-            globalns = self.globals
+            globalns = getattr(forward_module, "__dict__", self.globals)
         return evaluate_forward_ref(typ, globalns, self.__dict__)
 
     def get_declared_hook(self, method_name: str) -> typing.Any:

mashumaro/core/meta/helpers.py

@@ -680,6 +680,8 @@ def get_function_arg_annotation(
     annotation = parameter.annotation
     if annotation is inspect.Signature.empty:
         raise ValueError(f"Argument {arg_name} doesn't have annotation")
+    if isinstance(annotation, str):
+        annotation = ForwardRef(annotation, module=inspect.getmodule(function))
     return annotation
 
 
@@ -689,6 +691,8 @@ def get_function_return_annotation(
     annotation = inspect.signature(function).return_annotation
     if annotation is inspect.Signature.empty:
         raise ValueError("Function doesn't have return annotation")
+    if isinstance(annotation, str):
+        annotation = ForwardRef(annotation, module=inspect.getmodule(function))
     return annotation