from typing import Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    model_config = {"extra": "forbid"}

    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/{item_id}")
async def read_item(item_id: str, q: str | None = None, short: bool = False):
    item = {"item_id": item_id}
    if q:
        item.update({"q": q})
    if not short:
        item.update(
            {"description": "This is an amazing item that has a long description"}
        )

* Wenn der Parameter vom Typ eines **Pydantic-Modells** ist, wird er als Request**body** interpretiert.

/// note | "Hinweis"

FastAPI weiß, dass der Wert von `q` nicht erforderlich ist, wegen des definierten Defaultwertes `= None`

Das `Union` in `Union[str, None]` wird von FastAPI nicht verwendet, aber es erlaubt Ihrem Editor, Sie besser zu unterstützen und Fehler zu erkennen.

///

## Ohne Pydantic

* Se o parâmetro é declarado como um **modelo Pydantic**, será interpretado como o **corpo** da requisição.

/// note | "Observação"

O FastAPI saberá que o valor de `q` não é obrigatório por causa do valor padrão `= None`.

O `Union` em `Union[str, None]` não é utilizado pelo FastAPI, mas permite ao seu editor de texto lhe dar um suporte melhor e detectar erros.

///

## Sem o Pydantic

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.body_nested_models.tutorial009 import app

    client = TestClient(app)
    return client


def test_post_body(client: TestClient):
    data = {"2": 2.2, "3": 3.3}
    response = client.post("/index-weights/", json=data)
    assert response.status_code == 200, response.text

from fastapi.testclient import TestClient

from docs_src.openapi_webhooks.tutorial001 import app

client = TestClient(app)


def test_get():
    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == ["Rick", "Morty"]


def test_dummy_webhook():
    # Just for coverage
    app.webhooks.routes[0].endpoint({})


def test_openapi_schema():

from typing import Annotated, Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    model_config = {"extra": "forbid"}

    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")

from typing import Annotated

from fastapi import FastAPI, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get")],
    q: Annotated[str | None, Query(alias="item-query")] = None,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

///

from fastapi.testclient import TestClient

from docs_src.extra_models.tutorial005 import app

client = TestClient(app)


def test_get_items():
    response = client.get("/keyword-weights/")
    assert response.status_code == 200, response.text
    assert response.json() == {"foo": 2.3, "bar": 3.4}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text