fix: #3357 output schema names for Literal types (#3358)

Author: Aphroq

src/agents/agent_output.py

@@ -180,15 +180,16 @@ def _is_subclass_of_base_model_or_dict(t: Any) -> bool:
     return issubclass(t, BaseModel | dict)
 
 
-def _type_to_str(t: type[Any]) -> str:
+def _type_to_str(t: Any) -> str:
     origin = get_origin(t)
     args = get_args(t)
 
     if origin is None:
         # It's a simple type like `str`, `int`, etc.
-        return t.__name__
+        return getattr(t, "__name__", repr(t))
     elif args:
         args_str = ", ".join(_type_to_str(arg) for arg in args)
-        return f"{origin.__name__}[{args_str}]"
+        origin_name = getattr(origin, "__name__", str(origin))
+        return f"{origin_name}[{args_str}]"
     else:
         return str(t)

tests/test_output_tool.py

@@ -1,5 +1,5 @@
 import json
-from typing import Any
+from typing import Any, Literal, cast
 
 import pytest
 from pydantic import BaseModel
@@ -77,6 +77,18 @@ def test_structured_output_list():
     assert validated == ["foo", "bar"]
 
 
+def test_structured_output_literal_name_handles_literal_values():
+    output_schema = AgentOutputSchema(output_type=cast(type[Any], Literal["ok"]))
+
+    assert output_schema.name() == "Literal['ok']"
+
+
+def test_structured_output_nested_literal_name_handles_literal_values():
+    output_schema = AgentOutputSchema(output_type=list[Literal["ok", "done"]])
+
+    assert output_schema.name() == "list[Literal['ok', 'done']]"
+
+
 def test_structured_output_generic_dict_is_not_wrapped():
     output_schema = AgentOutputSchema(output_type=dict[str, int], strict_json_schema=False)
     assert output_schema.output_type == dict[str, int]