### Das Attribut `app.dependency_overrides` verwenden { #use-the-app-dependency-overrides-attribute }

### Utilize o atributo `app.dependency_overrides` { #use-the-app-dependency-overrides-attribute }

Para estes casos, a sua aplicação **FastAPI** possui o atributo `app.dependency_overrides`. Ele é um simples `dict`.

from fastapi.responses import PlainTextResponse
from fastapi.testclient import TestClient

from docs_src.advanced_middleware.tutorial003_py39 import app


@app.get("/large")
async def large():
    return PlainTextResponse("x" * 4000, status_code=200)


client = TestClient(app)


def test_middleware():
    response = client.get("/large", headers={"accept-encoding": "gzip"})
    assert response.status_code == 200, response.text

RegularSessionsDep = Annotated[
    tuple[NamedSession, Session], Depends(get_named_regular_func_session)
]

app = FastAPI()


@app.websocket("/function-scope")
async def function_scope(websocket: WebSocket, session: SessionFuncDep) -> Any:
    await websocket.accept()
    await websocket.send_json({"is_open": session.open})


@app.websocket("/request-scope")
async def request_scope(websocket: WebSocket, session: SessionRequestDep) -> Any:

        tuple[int, ...]: [1, 2, 3],  # `tuple` is converted to `list`
    }
    for test_type, expect in types.items():
        app = FastAPI()

        @app.post("/", response_model=test_type)
        def post_endpoint(input: test_type):
            return input

        res = TestClient(app).post("/", json=expect)
        assert res.status_code == 200, res.json()

from pydantic import BaseModel, Field

app = FastAPI()


class FormModel(BaseModel):
    username: str
    lastname: str
    age: Optional[int] = None
    tags: list[str] = ["foo", "bar"]
    alias_with: str = Field(alias="with", default="nothing")


class FormModelExtraAllow(BaseModel):
    param: str

    model_config = {"extra": "allow"}


@app.post("/form/")

```Python
from unicorn import UnicornMiddleware

app = SomeASGIApp()

new_app = UnicornMiddleware(app, some_config="rainbow")
```

Но FastAPI (точнее, Starlette) предоставляет более простой способ, который гарантирует корректную обработку внутренних ошибок сервера и корректную работу пользовательских обработчиков исключений.

Для этого используйте `app.add_middleware()` (как в примере с CORS).

```Python

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class MyModel(BaseModel):
    """
    A model with a form feed character in the title.
    \f
    Text after form feed character.
    """


@app.get("/foo")
def foo(v: MyModel):  # pragma: no cover
    pass


client = TestClient(app)


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

from fastapi.testclient import TestClient

items = {}


@asynccontextmanager
async def lifespan(app: FastAPI):
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}
    yield
    # clean up items
    items.clear()


app = FastAPI(lifespan=lifespan)


@app.get("/items/{item_id}")
async def read_items(item_id: str):
    return items[item_id]


def test_read_items():

You can **read items**.

## Users

You will be able to:

* **Create users** (_not implemented_).
* **Read users** (_not implemented_).
"""

app = FastAPI(
    title="ChimichangApp",
    description=description,
    summary="Deadpool's favorite app. Nuff said.",
    version="0.0.1",
    terms_of_service="http://example.com/terms/",
    contact={
        "name": "Deadpoolio the Amazing",