}
        },
        executor);
  }

  /**
   * Enqueues a task to run when the previous task (if any) completes.
   *
   * <p>Cancellation does not propagate from the output future to the future returned from {@code
   * callable} or a callable that has begun to execute, but if the output future is cancelled before
   * {@link AsyncCallable#call()} is invoked, {@link AsyncCallable#call()} will not be invoked.

these terms and conditions, and the Licensor grants You such rights in
consideration of benefits the Licensor receives from making the
Licensed Material available under these terms and conditions.


Section 1 -- Definitions.

  a. Adapted Material means material subject to Copyright and Similar
     Rights that is derived from or based upon the Licensed Material
     and in which the Licensed Material is translated, altered,

import pytest
from dirty_equals import IsDict
from fastapi import APIRouter, FastAPI, Query
from fastapi.testclient import TestClient
from typing_extensions import Annotated

app = FastAPI()


@app.get("/default")
async def default(foo: Annotated[str, Query()] = "foo"):
    return {"foo": foo}


@app.get("/required")
async def required(foo: Annotated[str, Query(min_length=1)]):
    return {"foo": foo}


@app.get("/multiple")

from typing import Any

import orjson
from fastapi import APIRouter, FastAPI
from fastapi.responses import HTMLResponse, JSONResponse, PlainTextResponse
from fastapi.testclient import TestClient


class ORJSONResponse(JSONResponse):
    media_type = "application/x-orjson"

    def render(self, content: Any) -> bytes:
        return orjson.dumps(content)


class OverrideResponse(JSONResponse):
    media_type = "application/x-override"

### Import `Query` and `Annotated`

To achieve that, first import:

* `Query` from `fastapi`
* `Annotated` from `typing` (or from `typing_extensions` in Python below 3.9)

//// tab | Python 3.10+

In Python 3.9 or above, `Annotated` is part of the standard library, so you can import it from `typing`.

```Python hl_lines="1  3"
{!> ../../docs_src/query_params_str_validations/tutorial002_an_py310.py!}
```

from fastapi import Depends, FastAPI, HTTPException
from typing_extensions import Annotated

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("Oops, we didn't raise again, Britney 😱")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):
    if item_id == "portal-gun":

from fastapi import FastAPI
from fastapi.openapi.utils import get_openapi

app = FastAPI()


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


def custom_openapi():
    if app.openapi_schema:
        return app.openapi_schema
    openapi_schema = get_openapi(
        title="Custom title",
        version="2.5.0",
        summary="This is a very custom OpenAPI schema",

from typing import Annotated

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: str | None = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q

from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/", openapi_extra={"x-custom-extension": "value"})
def route_with_extras():
    return {}


client = TestClient(app)


def test_get_route():
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert response.json() == {}


def test_openapi():

from fastapi import FastAPI
from fastapi.testclient import TestClient

swagger_ui_init_oauth = {"clientId": "the-foo-clients", "appName": "The Predendapp"}

app = FastAPI(swagger_ui_init_oauth=swagger_ui_init_oauth)


@app.get("/items/")
async def read_items():
    return {"id": "foo"}


client = TestClient(app)


def test_swagger_ui():
    response = client.get("/docs")
    assert response.status_code == 200, response.text