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.responses import ORJSONResponse

app = FastAPI(default_response_class=ORJSONResponse)


@app.get("/items/")
async def read_items():

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/", openapi_extra={"x-aperture-labs-portal": "blue"})
async def read_items():

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": False})


@app.get("/users/{username}")
async def read_user(username: str):

Кроме того, Ваше приложение **FastAPI** может состоять из нескольких файлов, модулей и т.п.

### Файл приложения **FastAPI** { #fastapi-app-file }

Допустим, структура файлов Вашего приложения похожа на ту, что описана на странице [Более крупные приложения](bigger-applications.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

В файле `main.py` находится Ваше приложение **FastAPI**:

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: str | None = Header(default=None, convert_underscores=False),
):

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyQuery(name="key")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User = Depends(get_current_user)):

Client = Annotated[DummyClient, Depends(get_client)]


@pytest.fixture(name="client")
def client_fixture() -> TestClient:
    app = FastAPI()

    @app.get("/")
    async def get_people(client: Client) -> list:
        return await client.get_people()

    client = TestClient(app)
    return client


def test_get(client: TestClient):
    response = client.get("/")

        .Builder()
        .commonName("cash.app")
        .build()
    val certificate = heldCertificate.certificate
    assertThat(certificate.getSubjectX500Principal().name).isEqualTo("CN=cash.app")
  }

  @Test
  fun organizationalUnit() {
    val heldCertificate =
      HeldCertificate
        .Builder()
        .commonName("cash.app")
        .organizationalUnit("cash")
        .build()

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


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