🐛 Update safe_status_message to truncate messages to 50 characters and append ellipsis; enhance tests for truncation behavior

Author: pcrespov

packages/service-library/src/servicelib/aiohttp/rest_responses.py

@@ -130,16 +130,27 @@ def _pred(obj) -> bool:
     return http_statuses
 
 
-def safe_status_message(message: str | None, max_length: int = 1500) -> str | None:
+def safe_status_message(message: str | None, max_length: int = 50) -> str | None:
     """
     Truncates a status-message (i.e. `reason` in HTTP errors) to a maximum length, replacing newlines with spaces.
 
+    If the message is longer than max_length, it will be truncated and "..." will be appended.
+
     This prevents issues such as:
         - `aiohttp.http_exceptions.LineTooLong`: 400, message: Got more than 8190 bytes when reading Status line is too long.
         - Multiline not allowed in HTTP reason attribute (aiohttp now raises ValueError).
 
     See:
+        - When to use http status and/or text messages https://github.com/ITISFoundation/osparc-simcore/pull/7760
         - [RFC 9112, Section 4.1: HTTP/1.1 Message Syntax and Routing](https://datatracker.ietf.org/doc/html/rfc9112#section-4.1) (status line length limits)
         - [RFC 9110, Section 15.5: Reason Phrase](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5) (reason phrase definition)
     """
-    return message.replace("\n", " ")[:max_length] if message else None
+    if not message:
+        return None
+
+    flat_message = message.replace("\n", " ")
+    if len(flat_message) <= max_length:
+        return flat_message
+
+    # Truncate and add ellipsis
+    return flat_message[: max_length - 3] + "..."

packages/service-library/tests/aiohttp/test_rest_responses.py

@@ -109,11 +109,11 @@ def tests_exception_to_response(skip_details: bool, error_code: ErrorCodeStr | N
             "Message\nwith\nnewlines",
             "Message with newlines",
         ),  # Newlines are replaced with spaces
-        ("A" * 2000, "A" * 1500),  # Long message gets truncated to max_length (1500)
+        ("A" * 100, "A" * 47 + "..."),  # Long message gets truncated with ellipsis
         (
-            "Line1\nLine2\nLine3" + "X" * 1500,
-            "Line1 Line2 Line3" + "X" * 1483,
-        ),  # Combined case: newlines and truncation
+            "Line1\nLine2\nLine3" + "X" * 100,
+            "Line1 Line2 Line3" + "X" * 30 + "...",
+        ),  # Combined case: newlines and truncation with ellipsis
     ],
     ids=[
         "none_input",
@@ -137,6 +137,9 @@ def test_safe_status_message(input_message: str | None, expected_output: str | N
     # Check length constraint is respected
     if result_custom is not None:
         assert len(result_custom) <= custom_max
+        # Check that ellipsis is added when truncated
+        if input_message and len(input_message.replace("\n", " ")) > custom_max:
+            assert result_custom.endswith("...")
 
     # Verify it can be used in a web response without raising exceptions
     try: