You can use `async def` or normal `def`.

And you can declare dependencies with `async def` inside of normal `def` *path operation functions*, or `def` dependencies inside of `async def` *path operation functions*, etc.

It doesn't matter. **FastAPI** will know what to do.

/// note

        {"detail": exc.detail}, status_code=exc.status_code, headers=headers
    )


async def request_validation_exception_handler(
    request: Request, exc: RequestValidationError
) -> JSONResponse:
    return JSONResponse(
        status_code=422,
        content={"detail": jsonable_encoder(exc.errors())},
    )


async def websocket_request_validation_exception_handler(

client = TestClient(app)


def test_get_items():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == ["Portal gun", "Plumbus"]


def test_get_users():
    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == ["Rick", "Morty"]


def test_openapi_schema():

    GradleVersion baseVersion
    Map<ApiChange, String> acceptedChanges

    static AcceptedApiChanges parse(List<String> jsonTexts) {
        def acceptedApiChanges = new AcceptedApiChanges()
        acceptedApiChanges.acceptedChanges = [:]
        for (String jsonText : jsonTexts) {
            def json = new Gson().fromJson(jsonText, new TypeToken<Map<String, List<AcceptedApiChange>>>() {}.type)

Это обычная функция, которая может принимать параметры.

Это может быть как `async def`, так и обычная функция `def`, **FastAPI** знает, как корректно её выполнить.

В этом случае функция задачи будет записывать данные в файл (имитируя отправку письма).

Так как операция записи не использует `async` и `await`, мы определим функцию как обычную `def`:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[6:9] *}

    params=[
        "tutorial001_py39",
        pytest.param("tutorial001_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_updates.{request.param}")

    client = TestClient(mod.app)
    return client


def test_get(client: TestClient):
    response = client.get("/items/baz")
    assert response.status_code == 200, response.text

    app = FastAPI()

    @app.get("/facilities/{facility_id}")
    def get_facility(facility_id: str) -> Facility:
        return Facility(
            id=facility_id,
            address=Address(line_1="123 Main St", city="Anytown", state_province="CA"),
        )

    client = TestClient(app)
    return client


def test_get(client: TestClient):
    response = client.get("/facilities/42")

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial004_py39"),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.extra_models.{request.param}")

    client = TestClient(mod.app)
    return client


def test_get_items(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 200, response.text

    Read more about it in the
    [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).
    """

    def render(self, content: Any) -> bytes:
        assert ujson is not None, "ujson must be installed to use UJSONResponse"
        return ujson.dumps(content, ensure_ascii=False).encode("utf-8")


class ORJSONResponse(JSONResponse):

        pytest.param("tutorial003_py39"),
        pytest.param("tutorial003_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.dataclasses_.{request.param}")

    client = TestClient(mod.app)
    client.headers.clear()
    return client


def test_post_authors_item(client: TestClient):
    response = client.post(
        "/authors/foo/items/",