"item": {
            "name": "Foo",
            "price": 50.5,
            "description": None,
            "tax": None,
        },
        "user": {"username": "Dave", "full_name": None},
    }


def test_post_body_no_data(client: TestClient):
    response = client.put("/items/5", json=None)
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {

from pydantic import BaseModel as BaseModelV2
from pydantic.v1 import BaseModel


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


class ItemV2(BaseModelV2):
    name: str
    description: str | None = None
    size: float


app = FastAPI()


@app.post("/items/", response_model=ItemV2)
async def create_item(item: Item):

Teníamos esta anotación de tipo:

```Python
q: str | None = None
```

Lo que haremos es envolver eso con `Annotated`, para que se convierta en:

```Python
q: Annotated[str | None] = None
```

Ambas versiones significan lo mismo, `q` es un parámetro que puede ser un `str` o `None`, y por defecto, es `None`.

Ahora vamos a lo divertido. 🎉

HSPLokhttp3/Dispatcher;->promoteAndExecute()Z
HSPLokhttp3/Dns$Companion$DnsSystem;-><init>()V
HSPLokhttp3/Dns$Companion$DnsSystem;->lookup(Ljava/lang/String;)Ljava/util/List;
HSPLokhttp3/Dns;-><clinit>()V
HSPLokhttp3/EventListener$Companion$NONE$1;-><init>()V
HSPLokhttp3/EventListener;-><clinit>()V
HSPLokhttp3/EventListener;-><init>()V
HSPLokhttp3/EventListener;->callEnd(Lokhttp3/Call;)V
HSPLokhttp3/EventListener;->callFailed(Lokhttp3/Call;Ljava/io/IOException;)V

                "loc": ["query", "token"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["header", "x-token"],
                "msg": "Field required",
                "input": None,
            },
        ]
    }


def test_put_invalid_header(client: TestClient):

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

app = FastAPI()


@app.post("/files")
async def upload_files(files: list[bytes] | None = File(None)):
    if files is None:
        return {"files_count": 0}
    return {"files_count": len(files), "sizes": [len(f) for f in files]}


def test_optional_bytes_list():
    client = TestClient(app)
    response = client.post(
        "/files",

app = FastAPI()


@app.get("/items/")
def read_items(q: str | None = Param(default=None)):  # type: ignore
    return {"q": q}


client = TestClient(app)


def test_default_param_query_none():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == {"q": None}


def test_default_param_query():
    response = client.get("/items/?q=foo")

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "query"],
                "msg": "Field required",
                "input": None,
            }
        ]
    }


def test_query_query_baz():
    response = client.get("/query?query=baz")
    assert response.status_code == 200
    assert response.json() == "foo bar baz"

    routes have failed but this is no exposed in the API.

 *  **ResponseSource is gone.** This enum exposed whether a response came from
    the cache, network, or both. OkHttp 2 offers more detail with raw access to
    the cache and network responses in the new `Response` class.

 *  **TunnelRequest is gone.** It specified how to connect to an HTTP proxy.
    OkHttp 2 uses the new `Request` class for this.

from fastapi.encoders import jsonable_encoder
from fastapi.responses import JSONResponse
from pydantic import BaseModel


class Item(BaseModel):
    title: str
    timestamp: datetime
    description: str | None = None


app = FastAPI()


@app.put("/items/{id}")
def update_item(id: str, item: Item):
    json_compatible_item_data = jsonable_encoder(item)