Ref: https://github.com/Kludex/starlette/pull/3117
    """

    def __init__(self, router: "APIRouter") -> None:
        self._router = router

    async def __aenter__(self) -> None:
        await self._router._startup()

    async def __aexit__(self, *exc_info: object) -> None:
        await self._router._shutdown()

    def __call__(self: _T, app: object) -> _T:
        return self

app = FastAPI()


class FixedContentQueryChecker:
    def __init__(self, fixed_content: str):
        self.fixed_content = fixed_content

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")
async def read_query_check(fixed_content_included: bool = Depends(checker)):

from functools import lru_cache
from typing import Annotated

from fastapi import Depends, FastAPI

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: Annotated[config.Settings, Depends(get_settings)]):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,

from fastapi import FastAPI, File, UploadFile

app = FastAPI()


@app.post("/files/")
async def create_file(file: bytes = File(description="A file read as bytes")):
    return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(
    file: UploadFile = File(description="A file read as UploadFile"),
):

class PartialGitHubEventIssue(BaseModel):
    number: int | None = None


class PartialGitHubEvent(BaseModel):
    pull_request: PartialGitHubEventIssue | None = None


def get_graphql_response(
    *,
    settings: Settings,
    query: str,
    after: str | None = None,
    category_id: str | None = None,
    discussion_number: int | None = None,

## HTTPX { #httpx }

Mesmo que a sua aplicação **FastAPI** utilize funções normais com `def` no lugar de `async def`, ela ainda é uma aplicação `async` por baixo dos panos.

    "{$callback_url}/invoices/{$request.body.id}", response_model=InvoiceEventReceived
)
def invoice_notification(body: InvoiceEvent):
    pass  # pragma: nocover


class Event(BaseModel):
    name: str
    total: float


events_callback_router = APIRouter()


@events_callback_router.get("{$callback_url}/events/{$request.body.title}")
def event_callback(event: Event):
    pass  # pragma: nocover

class Foo(FooBaseModel):
    pass


app = FastAPI()


@app.post("/")
async def post(
    foo: Foo | None = None,
):
    return foo


client = TestClient(app)


def test_call_invalid():
    response = client.post("/", json={"foo": {"bar": "baz"}})
    assert response.status_code == 422


def test_call_valid():
    response = client.post("/", json={})
    assert response.status_code == 200

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


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


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

from fastapi.testclient import TestClient
from typing_extensions import TypeAliasType


async def some_value() -> int:
    return 123


DependedValue = TypeAliasType(
    "DependedValue", Annotated[int, Depends(some_value)], type_params=()
)


def test_pep695_type_dependencies():
    app = FastAPI()

    @app.get("/")
    async def get_with_dep(value: DependedValue) -> str:  # noqa
        return f"value: {value}"