Der Query-Parameter `q` hat den Typ `str | None`, das bedeutet, dass er vom Typ `str` sein kann, aber auch `None`, und tatsächlich ist der Defaultwert `None`, sodass FastAPI weiß, dass er nicht erforderlich ist.

/// note | Hinweis

FastAPI erkennt, dass der Wert von `q` nicht erforderlich ist, aufgrund des Defaultwertes `= None`.

@pytest.mark.parametrize(
    "path",
    ["/optional-list-str", "/model-optional-list-str"],
)
def test_optional_list_str_missing(path: str):
    client = TestClient(app)
    response = client.post(path)
    assert response.status_code == 200, response.text
    assert response.json() == {"p": None}


@pytest.mark.parametrize(
    "path",
    ["/optional-list-str", "/model-optional-list-str"],
)
def test_optional_list_str(path: str):

    *,
    cloned_types: Optional[MutableMapping[type[BaseModel], type[BaseModel]]] = None,
) -> ModelField:
    return field


def generate_operation_id_for_path(
    *, name: str, path: str, method: str
) -> str:  # pragma: nocover
    warnings.warn(
        message="fastapi.utils.generate_operation_id_for_path() was deprecated, "
        "it is not used internally, and will be removed soon",

    return values


async def request_body_to_args(
    body_fields: list[ModelField],
    received_body: Optional[Union[dict[str, Any], FormData]],
    embed_body_fields: bool,
) -> tuple[dict[str, Any], list[dict[str, Any]]]:
    values: dict[str, Any] = {}
    errors: list[dict[str, Any]] = []
    assert body_fields, "request_body_to_args() should be called with fields"

    description: Optional[str] = None
    content: dict[str, MediaType]
    required: Optional[bool] = None


class Link(BaseModelWithConfig):
    operationRef: Optional[str] = None
    operationId: Optional[str] = None
    parameters: Optional[dict[str, Union[Any, str]]] = None
    requestBody: Optional[Union[Any, str]] = None
    description: Optional[str] = None
    server: Optional[Server] = None

    # TODO: In that case, define if File() should support example/examples too
    # @app.post("/form_example")
    # def form_example(firstname: str = Form(example="John")):
    #     return firstname

    # @app.post("/form_examples")
    # def form_examples(
    #     lastname: str = Form(
    #         ...,
    #         examples={
    #             "example1": {"summary": "last name summary", "value": "Doe"},

@pytest.mark.parametrize(
    "path",
    ["/optional-str", "/model-optional-str"],
)
def test_optional_str_missing(path: str):
    client = TestClient(app)
    response = client.get(path)
    assert response.status_code == 200
    assert response.json() == {"p": None}


@pytest.mark.parametrize(
    "path",
    ["/optional-str", "/model-optional-str"],
)
def test_optional_str(path: str):
    client = TestClient(app)

    metadata: dict[str, Any]


class LargeOut(BaseModel):
    items: list[dict[str, Any]]
    metadata: dict[str, Any]


app = FastAPI()


@app.post("/sync/validated", response_model=ItemOut)
def sync_validated(item: ItemIn, dep: Annotated[int, Depends(dep_b)]):
    return ItemOut(name=item.name, value=item.value, dep=dep)


@app.get("/sync/dict-no-response-model")
def sync_dict_no_response_model():

@pytest.mark.parametrize(
    "path",
    ["/optional-list-str", "/model-optional-list-str"],
)
def test_optional_list_str_missing(path: str):
    client = TestClient(app)
    response = client.get(path)
    assert response.status_code == 200, response.text
    assert response.json() == {"p": None}


@pytest.mark.parametrize(
    "path",
    ["/optional-list-str", "/model-optional-list-str"],
)
def test_optional_list_str(path: str):

# Without aliases


@app.get("/required-list-str")
async def read_required_list_str(p: Annotated[list[str], Query()]):
    return {"p": p}


class QueryModelRequiredListStr(BaseModel):
    p: list[str]


@app.get("/model-required-list-str")
def read_model_required_list_str(p: Annotated[QueryModelRequiredListStr, Query()]):
    return {"p": p.p}