fix: read the error class name via type() in the sanitized envelopes

Instance __getattribute__ can intercept __class__ access; type() cannot
be intercepted, so the class-name interpolation can never escape the
handler.

Author: CyMule

test/api/test_api.py

@@ -694,6 +694,28 @@ def _raising_func() -> None:
     assert "<unrenderable error>" in body["status_code_text"]
 
 
+def test_invoke_survives_error_with_hostile_class_access():
+    class _HostileClassError(Exception):
+        status_code = 403
+
+        def __getattribute__(self, name: str):
+            if name == "__class__":
+                raise RuntimeError("__class__ exploded")
+            return super().__getattribute__(name)
+
+    def _raising_func() -> None:
+        raise _HostileClassError("original message")
+
+    client = TestClient(wrap_in_fastapi(func=_raising_func, plugin_id="mock_plugin"))
+
+    resp = client.post("/invoke")
+    assert resp.status_code == 200
+    body = resp.json()
+    assert body["status_code"] == 403
+    assert "_HostileClassError" in body["status_code_text"]
+    assert "original message" in body["status_code_text"]
+
+
 def test_precheck_survives_error_whose_str_raises():
     def _unrenderable_precheck() -> None:
         raise _UnrenderableError()

unstructured_platform_plugins/etl_uvicorn/api_generator.py

@@ -253,7 +253,7 @@ async def _stream_response():
                                     filedata_meta.model_dump()
                                 ),
                                 status_code=status_code_of(e),
-                                status_code_text=f"[{e.__class__.__name__}] {_safe_str(e)}",
+                                status_code_text=f"[{type(e).__name__}] {_safe_str(e)}",
                                 failure_category=failure_category_of(e),
                             ).model_dump_json()
                             + "\n"
@@ -308,7 +308,7 @@ async def _stream_response():
                 message_channels=message_channels,
                 filedata_meta=filedata_meta_model.model_validate(filedata_meta.model_dump()),
                 status_code=status_code_of(invoke_error),
-                status_code_text=f"[{invoke_error.__class__.__name__}] {_safe_str(invoke_error)}",
+                status_code_text=f"[{type(invoke_error).__name__}] {_safe_str(invoke_error)}",
                 failure_category=failure_category_of(invoke_error),
                 file_data=request_dict.get("file_data", None),
             )