test: Python 3.10+ union-style param in function tool

[RezaRahemtola]

What does this PR do?

Adds a test for the chat template generation issue fixed here: huggingface/transformers#35103

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline,
  Pull Request section?
• Was this discussed/approved via a Github issue or Telegram? Please add a link
  to it if that's the case.
• Did you write any new necessary tests?

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
14	1	13	0

View the top 1 failed tests by shortest run time

tests.tools.test_function_tools::test_function_new_union_style_param_tool

Stack Traces | 0.001s run time

fake_get_temperature_with_new_union_style_param_tool = <function fake_get_temperature_with_new_union_style_param_tool.<locals>.get_current_temperature at 0x7fac26b63400>

    def test_function_new_union_style_param_tool(
        fake_get_temperature_with_new_union_style_param_tool,
    ):
>       libertai_tool = Tool.from_function(
            fake_get_temperature_with_new_union_style_param_tool
        )

tests/tools/test_function_tools.py:12: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
libertai_agents/interfaces/tools.py:35: in from_function
    args_schema=get_json_schema(function),
../../../../..../pypoetry/virtualenvs/libertai-agents-cGTlWRjZ-py3.10/lib/python3.10.../transformers/utils/chat_template_utils.py:322: in get_json_schema
    json_schema = _convert_type_hints_to_json_schema(func)
../../../../..../pypoetry/virtualenvs/libertai-agents-cGTlWRjZ-py3.10/lib/python3.10.../transformers/utils/chat_template_utils.py:165: in _convert_type_hints_to_json_schema
    properties[param_name] = _parse_type_hint(param_type)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

hint = str | None

    def _parse_type_hint(hint: str) -> Dict:
        origin = get_origin(hint)
        args = get_args(hint)
    
        if origin is None:
            try:
                return _get_json_schema_type(hint)
            except KeyError:
                raise TypeHintParsingException(
                    "Couldn't parse this type hint, likely due to a custom class or object: ", hint
                )
    
        elif origin is Union:
            # Recurse into each of the subtypes in the Union, except None, which is handled separately at the end
            subtypes = [_parse_type_hint(t) for t in args if t is not type(None)]
            if len(subtypes) == 1:
                # A single non-null type can be expressed directly
                return_dict = subtypes[0]
            elif all(isinstance(subtype["type"], str) for subtype in subtypes):
                # A union of basic types can be expressed as a list in the schema
                return_dict = {"type": sorted([subtype["type"] for subtype in subtypes])}
            else:
                # A union of more complex types requires "anyOf"
                return_dict = {"anyOf": subtypes}
            if type(None) in args:
                return_dict["nullable"] = True
            return return_dict
    
        elif origin is list:
            if not args:
                return {"type": "array"}
            else:
                # Lists can only have a single type argument, so recurse into it
                return {"type": "array", "items": _parse_type_hint(args[0])}
    
        elif origin is tuple:
            if not args:
                return {"type": "array"}
            if len(args) == 1:
                raise TypeHintParsingException(
                    f"The type hint {str(hint).replace('typing.', '')} is a Tuple with a single element, which "
                    "we do not automatically convert to JSON schema as it is rarely necessary. If this input can contain "
                    "more than one element, we recommend "
                    "using a List[] type instead, or if it really is a single element, remove the Tuple[] wrapper and just "
                    "pass the element directly."
                )
            if ... in args:
                raise TypeHintParsingException(
                    "Conversion of '...' is not supported in Tuple type hints. "
                    "Use List[] types for variable-length"
                    " inputs instead."
                )
            return {"type": "array", "prefixItems": [_parse_type_hint(t) for t in args]}
    
        elif origin is dict:
            # The JSON equivalent to a dict is 'object', which mandates that all keys are strings
            # However, we can specify the type of the dict values with "additionalProperties"
            out = {"type": "object"}
            if len(args) == 2:
                out["additionalProperties"] = _parse_type_hint(args[1])
            return out
    
>       raise TypeHintParsingException("Couldn't parse this type hint, likely due to a custom class or object: ", hint)
E       transformers.utils.chat_template_utils.TypeHintParsingException: ("Couldn't parse this type hint, likely due to a custom class or object: ", str | None)

../../../../..../pypoetry/virtualenvs/libertai-agents-cGTlWRjZ-py3.10/lib/python3.10.../transformers/utils/chat_template_utils.py:150: TypeHintParsingException

To view more test analytics, go to the Test Analytics Dashboard
📢 Thoughts on this report? Let us know!