fix: log unexpected errors server-side, return generic message to client (#991) (#1057)

* fix(serve): log unexpected errors server-side, return generic message to client (#991)

Signed-off-by: SAY-5 <say.apm35@gmail.com>

* chore: remove em-dashes from comments

* test(serve): assert raw exception text does not leak

* test(serve): assert raw exception text does not leak

* refactor(serve): use MelleaLogger for unhandled error logging

Switch the serve handler's logger from the stdlib logging.getLogger to MelleaLogger.get_logger so unhandled errors surface through the shared mellea logging configuration.

Signed-off-by: SAY-5 <say.apm35@gmail.com>

* trim verbose comments

---------

Signed-off-by: SAY-5 <say.apm35@gmail.com>

Author: SAY-5

cli/serve/app.py

@@ -23,6 +23,7 @@
     ) from e
 
 from mellea.backends.model_options import ModelOption
+from mellea.core import MelleaLogger
 from mellea.helpers.openai_compatible_helpers import (
     build_completion_usage,
     build_tool_calls,
@@ -42,6 +43,8 @@
 from .streaming import stream_chat_completion_chunks
 from .utils import extract_finish_reason
 
+logger = MelleaLogger.get_logger()
+
 app = FastAPI(
     title="M serve OpenAI API Compatible Server",
     description="M programs that run as a simple OpenAI API-compatible server",
@@ -265,11 +268,11 @@ async def endpoint(request: ChatCompletionRequest):
                 message=f"Invalid request: {e!s}",
                 error_type="invalid_request_error",
             )
-        except Exception as e:
-            # Catch-all for any unexpected errors (including AttributeError)
+        except Exception:
+            logger.exception("Unhandled error in chat-completion handler")
             return create_openai_error_response(
                 status_code=500,
-                message=f"Internal server error: {e!s}",
+                message="Internal server error",
                 error_type="server_error",
             )
 

test/cli/test_serve_errors.py

@@ -128,7 +128,7 @@ def test_generic_error_handling(mock_module_generic_error, sample_request):
     assert "error" in data
     assert data["error"]["type"] == "server_error"
     assert "Internal server error" in data["error"]["message"]
-    assert "Unexpected error" in data["error"]["message"]
+    assert "Unexpected error" not in data["error"]["message"]
 
 
 @pytest.mark.unit

test/cli/test_serve_integration.py

@@ -569,4 +569,5 @@ def test_server_error_returns_500(self, client, mock_module):
         data = response.json()
         assert "error" in data
         assert data["error"]["type"] == "server_error"
-        assert "Internal error" in data["error"]["message"]
+        assert "Internal error" not in data["error"]["message"]
+        assert "Internal server error" in data["error"]["message"]