fix(api): chain original exception in 13 except blocks per PEP 3134 (#40738)

Co-authored-by: Harsh Kashyap <Harsh23Kashyap@users.noreply.github.com>

api/controllers/console/billing/billing.py

@@ -96,8 +96,8 @@ class PartnerTenants(Resource):
         try:
             click_id = req_data.click_id
             decoded_partner_key = base64.b64decode(partner_key).decode("utf-8")
-        except Exception:
-            raise BadRequest("Invalid partner_key")
+        except Exception as e:
+            raise BadRequest("Invalid partner_key") from e
 
         if not click_id or not decoded_partner_key or not current_user.id:
             raise BadRequest("Invalid partner information")

api/controllers/console/workspace/workspace.py

@@ -302,8 +302,8 @@ class SwitchWorkspaceApi(Resource):
         # Check whether the tenant_id belongs to the current account.
         try:
             TenantService.switch_tenant(current_user, args.tenant_id, session=session)
-        except Exception:
-            raise AccountNotLinkTenantError("Account not link tenant")
+        except Exception as e:
+            raise AccountNotLinkTenantError("Account not link tenant") from e
 
         new_tenant = TenantService.get_tenant_by_id(args.tenant_id, session=session)
         if new_tenant is None:

api/controllers/files/tool_files.py

@@ -67,8 +67,8 @@ class ToolFileApi(Resource):
         except NotFound:
             raise
 
-        except Exception:
-            raise UnsupportedFileTypeError()
+        except Exception as e:
+            raise UnsupportedFileTypeError() from e
 
         mime_type = tool_file.mime_type
         filename = tool_file.filename

api/controllers/inner_api/plugin/wraps.py

@@ -84,8 +84,8 @@ def get_user(tenant_id: str, user_id: str | None) -> EndUser:
                 session.flush()
                 session.refresh(user_model)
 
-    except Exception:
-        raise ValueError("user not found")
+    except Exception as e:
+        raise ValueError("user not found") from e
 
     return user_model
 
@@ -131,13 +131,13 @@ def plugin_data[**P, R](
         def decorated_view(*args: P.args, **kwargs: P.kwargs) -> R:
             try:
                 data = request.get_json()
-            except Exception:
-                raise ValueError("invalid json")
+            except Exception as e:
+                raise ValueError("invalid json") from e
 
             try:
                 payload = payload_type.model_validate(data)
             except Exception as e:
-                raise ValueError(f"invalid payload: {str(e)}")
+                raise ValueError(f"invalid payload: {str(e)}") from e
 
             kwargs["payload"] = payload
             return view_func(*args, **kwargs)

api/core/plugin/backwards_invocation/app.py

@@ -270,8 +270,8 @@ class PluginAppBackwardsInvocation(BaseBackwardsInvocation):
                 app = session.scalar(select(App).where(App.id == app_id, App.tenant_id == tenant_id).limit(1))
                 if app:
                     session.expunge(app)
-        except Exception:
-            raise ValueError("app not found")
+        except Exception as e:
+            raise ValueError("app not found") from e
 
         if not app:
             raise ValueError("app not found")

api/core/plugin/entities/parameters.py

@@ -241,8 +241,10 @@ def cast_parameter_value(typ: StrEnum, value: Any, /):
                 return str(value)
     except ValueError:
         raise
-    except Exception:
-        raise ValueError(f"The tool parameter value {repr(value)} is not in correct type of {as_normal_type(typ)}.")
+    except Exception as e:
+        raise ValueError(
+            f"The tool parameter value {repr(value)} is not in correct type of {as_normal_type(typ)}."
+        ) from e
 
 
 def init_frontend_parameter(rule: PluginParameter, type: StrEnum, value: Any):

api/core/plugin/impl/base.py

@@ -276,19 +276,19 @@ class BasePluginClient:
                 json_response = transformer(json_response)
             # https://stackoverflow.com/questions/59634937/variable-foo-class-is-not-valid-as-type-but-why
             rep = PluginDaemonBasicResponse[type_].model_validate(json_response)  # type: ignore
-        except Exception:
+        except Exception as e:
             msg = (
                 f"Failed to parse response from plugin daemon to PluginDaemonBasicResponse [{str(type_.__name__)}],"
                 f" url: {path}"
             )
             logger.exception(msg)
-            raise ValueError(msg)
+            raise ValueError(msg) from e
 
         if rep.code != 0:
             try:
                 error = PluginDaemonError.model_validate(json.loads(rep.message))
-            except Exception:
-                raise ValueError(f"{rep.message}, code: {rep.code}")
+            except Exception as e:
+                raise ValueError(f"{rep.message}, code: {rep.code}") from e
 
             self._handle_plugin_daemon_error(error.error_type, error.message)
         if rep.data is None:

api/core/rag/retrieval/output_parser/structured_chat.py

@@ -19,5 +19,5 @@ class StructuredChatOutputParser:
                     return ReactAction(response["action"], response.get("action_input", {}), text)
             else:
                 return ReactFinish({"output": text}, text)
-        except Exception:
-            raise ValueError(f"Could not parse LLM output: {text}")
+        except Exception as e:
+            raise ValueError(f"Could not parse LLM output: {text}") from e

api/services/tools/api_tools_manage_service.py

@@ -238,9 +238,9 @@ class ApiToolManageService:
 
             # try to parse schema, avoid SSRF attack
             ApiToolManageService.parser_api_schema(schema)
-        except Exception:
+        except Exception as e:
             logger.exception("parse api schema error")
-            raise ValueError("invalid schema, please check the url you provided")
+            raise ValueError("invalid schema, please check the url you provided") from e
 
         return {"schema": schema}
 
@@ -453,8 +453,8 @@ class ApiToolManageService:
 
         try:
             tool_bundles, _ = ApiBasedToolSchemaParser.auto_parse_to_tool_bundle(schema)
-        except Exception:
-            raise ValueError("invalid schema")
+        except Exception as e:
+            raise ValueError("invalid schema") from e
 
         # get tool bundle
         tool_bundle = next(filter(lambda tb: tb.operation_id == tool_name, tool_bundles), None)

api/tests/unit_tests/controllers/inner_api/plugin/test_plugin_wraps.py

@@ -219,8 +219,11 @@ class TestGetUser:
 
         event.listen(sqlite_plugin_engine, "before_cursor_execute", _raise_database_error)
         try:
-            with app.app_context(), pytest.raises(ValueError, match="user not found"):
+            with app.app_context(), pytest.raises(ValueError, match="user not found") as exc_info:
                 get_user("tenant123", "user123")
+            # PEP 3134: the re-raised ValueError must chain the underlying database error.
+            assert isinstance(exc_info.value.__cause__, RuntimeError)
+            assert str(exc_info.value.__cause__) == "Database error"
         finally:
             event.remove(sqlite_plugin_engine, "before_cursor_execute", _raise_database_error)
 
@@ -351,8 +354,11 @@ class TestPluginData:
 
         # Act & Assert - Malformed JSON triggers ValueError
         with app.test_request_context(data="not valid json", content_type="application/json"):
-            with pytest.raises(ValueError):
+            with pytest.raises(ValueError) as exc_info:
                 protected_view()
+            # PEP 3134: the re-raised ValueError must chain the underlying JSON parse failure.
+            assert exc_info.value.__cause__ is not None
+            assert isinstance(exc_info.value.__cause__, Exception)
 
     def test_should_raise_error_on_invalid_payload(self, app: Flask):
         """Test that ValueError is raised when payload validation fails"""
@@ -369,8 +375,11 @@ class TestPluginData:
 
         # Act & Assert
         with app.test_request_context(json={"data": "test"}):
-            with pytest.raises(ValueError, match="invalid payload"):
+            with pytest.raises(ValueError, match="invalid payload") as exc_info:
                 protected_view()
+            # PEP 3134: the re-raised ValueError must chain the original Exception from model_validate.
+            assert exc_info.value.__cause__ is not None
+            assert str(exc_info.value.__cause__) == "Validation failed"
 
     def test_should_work_as_parameterized_decorator(self, app: Flask):
         """Test that decorator works when used with parentheses"""

api/tests/unit_tests/core/plugin/test_plugin_entities.py

@@ -244,9 +244,15 @@ class TestPluginParameterEntities:
         with pytest.raises(
             ValueError,
             match=r"The tool parameter value <.*_BadString object at .* is not in correct type of string\.",
-        ):
+        ) as exc_info:
             cast_parameter_value(PluginParameterType.STRING, _BadString())
 
+        # PEP 3134: the re-raised ValueError must chain the underlying RuntimeError
+        # so the original traceback is preserved for debugging.
+        assert exc_info.value.__cause__ is not None
+        assert isinstance(exc_info.value.__cause__, RuntimeError)
+        assert str(exc_info.value.__cause__) == "boom"
+
     def test_init_frontend_parameter(self):
         rule = PluginParameter(
             name="choice",

api/tests/unit_tests/core/rag/retrieval/test_structured_chat_output_parser.py

@@ -1,3 +1,5 @@
+import json
+
 import pytest
 
 from core.rag.retrieval.output_parser.react_output import ReactAction, ReactFinish
@@ -65,5 +67,10 @@ class TestStructuredChatOutputParser:
         parser = StructuredChatOutputParser()
         text = 'Action:\n```json\n{"action":"search","action_input": }\n```'
 
-        with pytest.raises(ValueError, match="Could not parse LLM output"):
+        with pytest.raises(ValueError, match="Could not parse LLM output") as exc_info:
             parser.parse(text)
+
+        # PEP 3134: the re-raised ValueError must chain the underlying parse failure
+        # (json.JSONDecodeError on the malformed JSON) so the original traceback is preserved.
+        assert exc_info.value.__cause__ is not None
+        assert isinstance(exc_info.value.__cause__, json.JSONDecodeError)