from fastapi import Depends, FastAPI, Request, Response
from fastapi.testclient import TestClient

legacy_request_state_context_var: ContextVar[Optional[dict[str, Any]]] = ContextVar(
    "legacy_request_state_context_var", default=None
)

app = FastAPI()


async def set_up_request_state_dependency():
    request_state = {"user": "deadpond"}
    contextvar_token = legacy_request_state_context_var.set(request_state)
    yield request_state

class CustomError(Exception):
    pass


@router.websocket("/custom_error/")
async def router_ws_custom_error(websocket: WebSocket):
    raise CustomError()


def make_app(app=None, **kwargs):
    app = app or FastAPI(**kwargs)
    app.include_router(router)
    app.include_router(prefix_router, prefix="/prefix")
    app.include_router(native_prefix_route)
    return app

```Python
from typing import Union
from fastapi import Cookie, FastAPI, Header, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
def main(
    item_id: int = Path(gt=0),
    query: Union[str, None] = Query(default=None, max_length=10),
    session: Union[str, None] = Cookie(default=None, min_length=3),

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.services.MavenException;

@Experimental
public class ModelParserException extends MavenException {

    /**
     * The one-based index of the line containing the error.
     */
    private final int lineNumber;

    /**
     * The one-based index of the column containing the error.
     */
    private final int columnNumber;

from fastapi import FastAPI, Query
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/items/")
def read_items(q: list[int] = Query(default=None)):
    return {"q": q}


client = TestClient(app)


def test_multi_query():
    response = client.get("/items/?q=5&q=6")
    assert response.status_code == 200, response.text
    assert response.json() == {"q": [5, 6]}


def test_multi_query_incorrect():

Isso significa que, se você quiser atualizar o item `bar` usando `PUT` com um corpo contendo:

```Python
{
    "name": "Barz",
    "price": 3,
    "description": None,
}
```

Como ele não inclui o atributo já armazenado `"tax": 20.2`, o modelo de entrada assumiria o valor padrão de `"tax": 10.5`.

E os dados seriam salvos com esse "novo" `tax` de `10.5`.

Alternatively, if you don't have a way to provide a command line option like `--root-path` or equivalent, you can set the `root_path` parameter when creating your FastAPI app:

{* ../../docs_src/behind_a_proxy/tutorial002_py39.py hl[3] *}

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path` { #about-root-path }

        try {
            return CommonsCliUpgradeOptions.parse(context.parserRequest.args().toArray(new String[0]));
        } catch (ParseException e) {
            throw new IllegalArgumentException("Failed to parse command line options: " + e.getMessage(), e);
        }
    }

app = FastAPI()

security = HTTPBearer(auto_error=False)


@app.get("/users/me")
def read_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
):
    if credentials is None:
        return {"msg": "Create an account first"}
    return {"scheme": credentials.scheme, "credentials": credentials.credentials}


client = TestClient(app)


def test_security_http_bearer():

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/token", auto_error=False)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    if token is None:
        return {"msg": "Create an account first"}
    return {"token": token}


client = TestClient(app)


def test_no_token():
    response = client.get("/items")