fix: handle internal error and return HTTP 500

robotoff/app/api.py

@@ -1800,6 +1800,14 @@ def on_get(self, req: falcon.Request, resp: falcon.Response):
         resp.status = falcon.HTTP_200
 
 
+def custom_handle_uncaught_exception(
+    req: falcon.Request, resp: falcon.Response, ex: Exception, params
+):
+    """Handle uncaught exceptions and log them. Return a 500 error to the
+    client."""
+    raise falcon.HTTPInternalServerError(description=str(ex))
+
+
 cors = CORS(
     allow_all_origins=True,
     allow_all_headers=True,
@@ -1818,6 +1826,8 @@ def on_get(self, req: falcon.Request, resp: falcon.Response):
 }
 
 api.resp_options.media_handlers.update(extra_handlers)
+# Handle uncaught exceptions
+api.add_error_handler(Exception, custom_handle_uncaught_exception)
 
 # Parse form parameters
 api.req_options.auto_parse_form_urlencoded = True

tests/integration/test_api.py

@@ -3,6 +3,7 @@
 from datetime import datetime
 
 import pytest
+import requests
 from falcon import testing
 
 from robotoff.app import events
@@ -1252,6 +1253,21 @@ def test_predict_lang(client, mocker):
     assert result.json == {"predictions": expected_predictions}
 
 
+def test_predict_lang_http_error(client, mocker):
+    mocker.patch(
+        "robotoff.app.api.predict_lang",
+        side_effect=requests.exceptions.ConnectionError(),
+    )
+    result = client.simulate_get(
+        "/api/v1/predict/lang", params={"text": "hello", "k": 2}
+    )
+    assert result.status_code == 500
+    assert result.json == {
+        "description": "Internal Server Error",
+        "title": "500 Internal Server Error",
+    }
+
+
 def test_predict_product_language(client, peewee_db):
     barcode = "123456789"
     prediction_data_1 = {"count": {"en": 10, "fr": 5, "es": 3, "words": 18}}