Fix structured response validation and guard issubclass() for Python 3.10 compatibility (#67)

dapr_agents/llm/utils/response.py

@@ -1,10 +1,11 @@
-from typing import Union, Dict, Any, Type, Optional, Iterator, Literal, get_args
-from dapr_agents.llm.utils import StreamHandler, StructureHandler
-from dataclasses import is_dataclass, asdict
-from dapr_agents.types import ChatCompletion
-from collections.abc import Iterable
-from pydantic import BaseModel
 import logging
+from dataclasses import asdict, is_dataclass
+from typing import Any, Dict, Iterator, Literal, Optional, Type, Union
+
+from pydantic import BaseModel
+
+from dapr_agents.llm.utils import StreamHandler, StructureHandler
+from dapr_agents.types import ChatCompletion
 
 logger = logging.getLogger(__name__)
 
@@ -43,30 +44,26 @@ class ResponseHandler:
         else:
             if response_format:
                 structured_response_json = StructureHandler.extract_structured_response(
-                    response=response, llm_provider=llm_provider, structured_mode=structured_mode
+                    response=response,
+                    llm_provider=llm_provider,
+                    structured_mode=structured_mode,
                 )
 
-                # Processing Iterable Models
-                is_iterable = isinstance(response_format, Iterable)
-                if is_iterable:
-                    item_model = get_args(response_format)[0]
-                    response_format = StructureHandler.create_iterable_model(item_model)
-                
-                # Validating Response
+                # Normalize format and resolve actual model class
+                normalized_format = StructureHandler.normalize_iterable_format(response_format)
+                model_cls = StructureHandler.resolve_response_model(normalized_format)
+
+                if not model_cls:
+                    raise TypeError(f"Could not resolve a valid Pydantic model from response_format: {response_format}")
+
                 structured_response_instance = StructureHandler.validate_response(
-                    structured_response_json, response_format
+                    structured_response_json, normalized_format
                 )
 
-                if isinstance(structured_response_instance, response_format):
-                    logger.info("Structured output was successfully validated.")
-                    if is_iterable:
-                        logger.debug(f"Returning objects from an instance of {type(structured_response_instance)}.")
-                        return structured_response_instance.objects
-                    else:
-                        logger.debug(f"Returning an instance of {type(structured_response_instance)}.")
-                        return structured_response_instance
-                else:
-                    logger.error("Validation failed for structured response.")
+                logger.info("Structured output was successfully validated.")
+                if hasattr(structured_response_instance, "objects"):
+                    return structured_response_instance.objects
+                return structured_response_instance
 
             # Convert response to dictionary
             if isinstance(response, dict):

dapr_agents/llm/utils/structure.py

@@ -431,36 +431,38 @@ class StructureHandler:
     
     @staticmethod
     def resolve_all_pydantic_models(tp: Any) -> List[Type[BaseModel]]:
-        """
-        Extracts all Pydantic models from a typing annotation.
-
-        Handles:
-        - Single BaseModel
-        - List[BaseModel], Iterable[BaseModel]
-        - Union[...] with optional or multiple model types
-
-        Returns:
-            List[Type[BaseModel]]
-        """
         models = []
 
         tp = StructureHandler.unwrap_annotated_type(tp)
-
         origin = get_origin(tp)
         args = get_args(tp)
 
-        if isinstance(tp, type) and issubclass(tp, BaseModel):
-            return [tp]
+        if isinstance(tp, type):
+            try:
+                if issubclass(tp, BaseModel):
+                    return [tp]
+            except TypeError:
+                pass
 
         if origin in (list, List, tuple, Iterable) and args:
             inner = args[0]
-            if isinstance(inner, type) and issubclass(inner, BaseModel):
-                return [inner]
+            if isinstance(inner, type):
+                try:
+                    if issubclass(inner, BaseModel):
+                        return [inner]
+                except TypeError:
+                    pass
+            else:
+                logger.debug(f"[resolve] Skipping non-class inner: {inner} ({type(inner)})")
 
         if origin is Union:
             for arg in args:
-                if isinstance(arg, type) and issubclass(arg, BaseModel):
-                    models.append(arg)
+                if isinstance(arg, type):
+                    try:
+                        if issubclass(arg, BaseModel):
+                            models.append(arg)
+                    except TypeError:
+                        continue
 
         return list(dict.fromkeys(models))