Moonshot schema crashes on JSON Schema union types

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Merged to main. A stamp counts the issues a fix is linked to.

• #45579 fix(moonshot): handle union type arrays in tool schemas

  merged to main

  files: agent/moonshot_schema.py, tests/agent/test_moonshot_schema.py

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  • agent/moonshot_schema.py

    @@ -135,7 +135,14 @@ def _repair_schema(node: Any, is_schema: bool = True) -> Any:
     
     def _fill_missing_type(node: Dict[str, Any]) -> Dict[str, Any]:
         """Infer a reasonable ``type`` if this schema node has none."""
    -    if "type" in node and node["type"] not in {None, ""}:
    +    node_type = node.get("type")
    +    if isinstance(node_type, list):
    +        concrete = next(
    +            (t for t in node_type if isinstance(t, str) and t not in {"", "null"}),
    +            "string",
    +        )
    +        return {**node, "type": concrete}
    +    if "type" in node and node_type not in {None, ""}:
             return node
     
         # Heuristic: presence of ``properties`` → object, ``items`` → array, ``enum``

  • tests/agent/test_moonshot_schema.py

    @@ -397,3 +397,52 @@ def test_anyof_collapse_still_runs_nullable_and_enum_cleanup(self):
             assert db_type["type"] == "string"
             assert db_type["enum"] == ["mysql", "postgresql"], \
                 "null/empty enum values must be stripped after anyOf collapse"
    +
    +
    +class TestUnionTypeList:
    +    """Moonshot sanitizer accepts JSON Schema union type arrays."""
    +
    +    def test_union_type_list_normalizes_to_first_concrete_type(self):
    +        params = {
    +            "type": "object",
    +            "properties": {
    +                "limit": {
    +                    "type": ["number", "string"],
    +                    "description": "Max results",
    +                },
    +            },
    +        }
    +
    +        out = sanitize_moonshot_tool_parameters(params)
    +
    +        assert out["properties"]["limit"]["type"] == "number"
    +
    +    def test_union_type_list_skips_null_type(self):
    +        params = {
    +            "type": "object",
    +            "properties": {
    +                "name": {"type": ["null", "string"]},
    +            },
    +        }
    +
    +        out = sanitize_moonshot_tool_parameters(params)
    +
    +        assert out["properties"]["name"]["type"] == "string"
    +
    +    def test_union_type_list_with_enum_does_not_crash_or_mutate_input(self):
    +        params = {
    +            "type": "object",
    +            "properties": {
    +                "sort": {
    +                    "type": ["string", "null"],
    +                    "enum": ["asc", "desc", None, ""],
    +                },
    +            },
    +        }
    +
    +        out = sanitize_moonshot_tool_parameters(params)
    +
    +        sort = out["properties"]["sort"]
    +        assert sort["type"] == "string"
    +        assert sort["enum"] == ["asc", "desc"]
    +        assert params["properties"]["sort"]["type"] == ["string", "null"]