const int in_flight_nodes_limit)
      : status_(TF_NewStatus()),
        // If the context's default exector is set to async, re-using that in
        // each thread would cause collectives to deadlock. For consistency we
        // create a new sync executor for every thread.
        //
        // TODO(allenl): We should have an async API that works with the

import pytest
from httpx import AsyncClient

from .main import app


@pytest.mark.anyio
async def test_root():
    async with AsyncClient(app=app, base_url="http://test") as ac:
        response = await ac.get("/")
    assert response.status_code == 200

from fastapi import FastAPI

app = FastAPI()


class Tags(Enum):
    items = "items"
    users = "users"


@app.get("/items/", tags=[Tags.items])
async def get_items():
    return ["Portal gun", "Plumbus"]


@app.get("/users/", tags=[Tags.users])
async def read_users():

    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}


@app.get("/items/{item_id}", response_model=Item)
async def read_item(item_id: str):
    return items[item_id]


@app.put("/items/{item_id}", response_model=Item)
async def update_item(item_id: str, item: Item):
    update_item_encoded = jsonable_encoder(item)
    items[item_id] = update_item_encoded

}


@app.get(
    "/items/{item_id}/name",
    response_model=Item,
    response_model_include=["name", "description"],
)
async def read_item_name(item_id: str):
    return items[item_id]


@app.get("/items/{item_id}/public", response_model=Item, response_model_exclude=["tax"])
async def read_item_public_data(item_id: str):

app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,
        content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
    )


@app.get("/unicorns/{name}")
async def read_unicorn(name: str):
    if name == "yolo":
        raise UnicornException(name=name)

    description: str | None = None
    price: float
    tax: float | None = None
    tags: list[str] = []


@app.post("/items/", response_model=Item)
async def create_item(item: Item) -> Any:
    return item


@app.get("/items/", response_model=list[Item])
async def read_items() -> Any:
    return [
        {"name": "Portal Gun", "price": 42.0},
        {"name": "Plumbus", "price": 32.0},

    只要把它传递给 `Depends`，**FastAPI** 就知道该如何执行后续操作。

## 要不要使用 `async`？

**FastAPI** 调用依赖项的方式与*路径操作函数*一样，因此，定义依赖项函数，也要应用与路径操作函数相同的规则。

即，既可以使用异步的 `async def`，也可以使用普通的 `def` 定义依赖项。

在普通的 `def` *路径操作函数*中，可以声明异步的 `async def` 依赖项；也可以在异步的 `async def` *路径操作函数*中声明普通的 `def` 依赖项。

上述这些操作都是可行的，**FastAPI** 知道该怎么处理。

!!! note "笔记"

    如里不了解异步，请参阅[异步：*“着急了？”*](../../async.md){.internal-link target=_blank} 一章中 `async` 和 `await` 的内容。

    @app.post("/files/")
    async def create_file(file: Annotated[bytes, File()]):
        return {"file_size": len(file)}


    @app.post("/uploadfile/")
    async def create_upload_file(file: UploadFile):
        return {"filename": file.filename}
    ```
    """

    file: Annotated[
        BinaryIO,
        Doc("The standard Python file object (non-async)."),
    ]

## Использовать `async` или не `async`

Для зависимостей, вызванных **FastAPI** (то же самое, что и ваши *функции обработки пути*), те же правила, что приняты для определения ваших функций.

Вы можете использовать `async def` или обычное `def`.

Вы также можете объявить зависимости с `async def` внутри обычной `def` *функции обработки пути*, или `def` зависимости внутри `async def` *функции обработки пути*, и так далее.