feat(api): add FolderAlreadyExistsError exception handling

- Introduced `FolderAlreadyExistsError` to handle cases where a folder with the same name already exists, improving error management in folder operations.
- Updated the REST API to include this new exception in the error handling mechanism, providing clearer responses for folder-related requests.
- Refactored import statements for better organization and clarity in the codebase.
- Enhanced the `list_library_agents` and `list_favorite_library_agents` functions by simplifying the error handling logic and improving readability.

autogpt_platform/backend/backend/api/features/library/exceptions.py

@@ -2,3 +2,9 @@ class FolderValidationError(Exception):
     """Raised when folder operations fail validation."""
 
     pass
+
+
+class FolderAlreadyExistsError(FolderValidationError):
+    """Raised when a folder with the same name already exists in the location."""
+
+    pass

autogpt_platform/backend/backend/api/features/library/model.py

@@ -566,5 +566,5 @@ class LibraryAgentUpdateRequest(pydantic.BaseModel):
     )
     folder_id: Optional[str] = pydantic.Field(
         default=None,
-        description="Folder ID to move agent to (empty string for root)",
+        description="Folder ID to move agent to (None to move to root)",
     )

autogpt_platform/backend/backend/api/rest_api.py

@@ -45,7 +45,10 @@ from backend.api.features.chat.completion_consumer import (
     start_completion_consumer,
     stop_completion_consumer,
 )
-from backend.api.features.library.exceptions import FolderValidationError
+from backend.api.features.library.exceptions import (
+    FolderAlreadyExistsError,
+    FolderValidationError,
+)
 from backend.blocks.llm import DEFAULT_LLM_MODEL
 from backend.data.model import Credentials
 from backend.integrations.providers import ProviderName
@@ -278,6 +281,7 @@ async def validation_error_handler(
 
 
 app.add_exception_handler(PrismaError, handle_internal_http_error(500))
+app.add_exception_handler(FolderAlreadyExistsError, handle_internal_http_error(409, False))
 app.add_exception_handler(FolderValidationError, handle_internal_http_error(400, False))
 app.add_exception_handler(NotFoundError, handle_internal_http_error(404, False))
 app.add_exception_handler(NotAuthorizedError, handle_internal_http_error(403, False))