🐛 Fix signed integer list parsing

backend/utils/str_utils.py

@@ -1,6 +1,9 @@
+import logging
 import re
 from typing import List, Optional
 
+logger = logging.getLogger(__name__)
+
 
 def remove_think_blocks(text: str) -> str:
     """Remove <think>...</think> blocks including inner content."""
@@ -36,4 +39,16 @@ def convert_string_to_list(items_str: Optional[str]) -> List[int]:
     """
     if not items_str or items_str.strip() == "":
         return []
-    return [int(item.strip()) for item in items_str.split(",") if item.strip().isdigit()]
+
+    items = []
+    for raw_item in items_str.split(","):
+        item = raw_item.strip()
+        if not item:
+            continue
+        try:
+            items.append(int(item))
+        except ValueError:
+            logger.warning(
+                "convert_string_to_list: dropping non-integer entry %r", item
+            )
+    return items

test/backend/utils/test_str_utils.py

@@ -1,5 +1,10 @@
 import pytest
-from backend.utils.str_utils import remove_think_blocks, convert_list_to_string
+
+from backend.utils.str_utils import (
+    convert_list_to_string,
+    convert_string_to_list,
+    remove_think_blocks,
+)
 
 
 class TestStrUtils:
@@ -89,6 +94,23 @@ def test_convert_list_to_string_zero_and_negative(self):
         result = convert_list_to_string([0, -1, 5])
         assert result == "0,-1,5"
 
+    def test_convert_string_to_list_round_trips_signed_integers(self):
+        """Serialized signed integers should round-trip without data loss"""
+        serialized = convert_list_to_string([0, -1, 5])
+
+        assert convert_string_to_list(serialized) == [0, -1, 5]
+
+    def test_convert_string_to_list_accepts_whitespace_and_explicit_signs(self):
+        """Whitespace and explicit integer signs should be accepted"""
+        assert convert_string_to_list("  -2, +3, 0  ") == [-2, 3, 0]
+
+    def test_convert_string_to_list_warns_and_keeps_valid_entries(self, caplog):
+        """Malformed entries should be reported without discarding valid values"""
+        result = convert_string_to_list("invalid, 1, , -2")
+
+        assert result == [1, -2]
+        assert "dropping non-integer entry 'invalid'" in caplog.text
+
 
 if __name__ == "__main__":
     pytest.main()