"tax": 3.2,
                                        },
                                    },
                                    "converted": {
                                        "summary": "An example with converted data",
                                        "description": "FastAPI can convert price `strings` to actual `numbers` automatically",

) -> bool:
    try:
        return isinstance(cls, type) and issubclass(cls, class_or_tuple)  # type: ignore[arg-type]
    except TypeError:  # pragma: no cover
        if isinstance(cls, WithArgsTypes):
            return False
        raise  # pragma: no cover


def _annotation_is_sequence(annotation: Union[type[Any], None]) -> bool:
    if lenient_issubclass(annotation, (str, bytes)):
        return False

* 📝 Add dark mode auto switch to docs based on OS preference. PR [#4869](https://github.com/tiangolo/fastapi/pull/4869) by [@ComicShrimp](https://github.com/ComicShrimp).
* 🔥 Remove un-used old pending tests, already covered in other places. PR [#4891](https://github.com/tiangolo/fastapi/pull/4891) by [@tiangolo](https://github.com/tiangolo).

    "docs_src/settings/app03_py39/config_pv1.py",
    "docs_src/settings/app03_an_py39/config_pv1.py",
    "docs_src/settings/tutorial001_pv1_py39.py",
]

[tool.coverage.report]
show_missing = true
sort = "-Cover"

[tool.coverage.html]
show_contexts = true

[tool.ruff.lint]
select = [
    "E",  # pycodestyle errors
    "W",  # pycodestyle warnings
    "F",  # pyflakes
    "I",  # isort

try:
    import email_validator

    assert email_validator  # make autoflake ignore the unused import
    from pydantic import EmailStr
except ImportError:  # pragma: no cover

    class EmailStr(str):  # type: ignore
        @classmethod
        def __get_validators__(cls) -> Iterable[Callable[..., Any]]:
            yield cls.validate

        @classmethod

try:
    from pydantic_core.core_schema import (
        with_info_plain_validator_function as with_info_plain_validator_function,
    )
except ImportError:  # pragma: no cover
    from pydantic_core.core_schema import (
        general_plain_validator_function as with_info_plain_validator_function,  # noqa: F401
    )

RequiredParam = PydanticUndefined
Undefined = PydanticUndefined

    """Check if field type is a Union where all members are BaseModel subclasses."""
    from fastapi.types import UnionType

    origin = get_origin(field_type)

    # Check if it's a Union type (covers both typing.Union and types.UnionType in Python 3.10+)
    if origin is not Union and origin is not UnionType:
        return False

    union_args = get_args(field_type)

    for arg in union_args:

    app = FastAPI()
    with pytest.raises(FastAPIError) as e:

        @app.get("/")
        def read_root() -> Union[Response, None]:
            return Response(content="Foo")  # pragma: no cover

    assert "valid Pydantic field type" in e.value.args[0]
    assert "parameter response_model=None" in e.value.args[0]


def test_openapi_schema():
    response = client.get("/openapi.json")