🐛 fix(types.py): add output types to the frontend node to improve data integrity and error handling

✨ feat(types.py): add support for adding output types to the frontend node to ensure valid return types and improve error handling

src/backend/langflow/interface/types.py

@@ -288,6 +288,24 @@ def add_base_classes(frontend_node, return_types: List[str]):
                 frontend_node.get("base_classes").append(base_class)
 
 
+def add_output_types(frontend_node, return_types: List[str]):
+    """Add output types to the frontend node"""
+    for return_type in return_types:
+        if return_type not in CUSTOM_COMPONENT_SUPPORTED_TYPES or return_type is None:
+            raise HTTPException(
+                status_code=400,
+                detail={
+                    "error": (
+                        "Invalid return type should be one of: "
+                        f"{list(CUSTOM_COMPONENT_SUPPORTED_TYPES.keys())}"
+                    ),
+                    "traceback": traceback.format_exc(),
+                },
+            )
+
+        frontend_node.get("output_types").append(return_type)
+
+
 def build_langchain_template_custom_component(custom_component: CustomComponent):
     """Build a custom component template for the langchain"""
     try:
@@ -314,6 +332,9 @@ def build_langchain_template_custom_component(custom_component: CustomComponent)
         add_base_classes(
             frontend_node, custom_component.get_function_entrypoint_return_type
         )
+        add_output_types(
+            frontend_node, custom_component.get_function_entrypoint_return_type
+        )
         logger.debug("Added base classes")
         return frontend_node
     except Exception as exc: