"foo": {"id": "foo", "title": "Foo", "description": "There goes my hero"},
    "bar": {"id": "bar", "title": "Bar", "description": "The bartenders"},
}

app = FastAPI()


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


@app.get("/items/{item_id}", response_model=Item)
async def read_main(item_id: str, x_token: Annotated[str, Header()]):
    if x_token != fake_secret_token:

    then the types are still processed correctly, including dereferencing of forward
    references.
    """
    app = FastAPI()
    client = TestClient(app)
    app.post("/endpoint")(passthrough(forwardref_method))
    app.post("/endpoint2")(passthrough(passthrough(forwardref_method)))
    with client:
        response = client.post("/endpoint", json={"input": {"x": 0}})

from fastapi.testclient import TestClient

from .config import Settings
from .main import app, get_settings

client = TestClient(app)


def get_settings_override():
    return Settings(admin_email="******@****.***")


app.dependency_overrides[get_settings] = get_settings_override


def test_app():
    response = client.get("/info")
    data = response.json()
    assert data == {
        "app_name": "Awesome API",

La simplicidad del sistema de inyección de dependencias hace que **FastAPI** sea compatible con:

* todas las bases de datos relacionales
* bases de datos NoSQL
* paquetes externos
* APIs externas
* sistemas de autenticación y autorización
* sistemas de monitoreo de uso de la API
* sistemas de inyección de datos de response
* etc.

## Simple y Poderoso { #simple-and-powerful }

from fastapi.testclient import TestClient

app = FastAPI()


@app.delete(
    "/{id}",
    status_code=204,
    response_model=None,
)
async def delete_deployment(
    id: int,
    response: Response,
) -> Any:
    response.status_code = 400
    return {"msg": "Status overwritten", "id": id}


client = TestClient(app)


def test_dependency_set_status_code():

from fastapi import FastAPI, Security
from fastapi.security import OAuth2PasswordBearer
from fastapi.testclient import TestClient

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="/token",
    description="OAuth2PasswordBearer security scheme",
    auto_error=False,
)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    if token is None:

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

oid = OpenIdConnect(openIdConnectUrl="/openid")


class User(BaseModel):
    username: str


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


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

from fastapi.testclient import TestClient

app = FastAPI()


@app.post("/")
async def get(
    x: Annotated[float, Query(allow_inf_nan=True)] = 0,
    y: Annotated[float, Query(allow_inf_nan=False)] = 0,
    z: Annotated[float, Query()] = 0,
    b: Annotated[float, Body(allow_inf_nan=False)] = 0,
) -> str:
    return "OK"


client = TestClient(app)


@pytest.mark.parametrize(
    "value,code",

from typing import Annotated

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

app = FastAPI()


@app.post("/form/")
def post_form(username: Annotated[str, Form()]):
    return username


client = TestClient(app)


def test_single_form_field():
    response = client.post("/form/", data={"username": "Rick"})
    assert response.status_code == 200, response.text
    assert response.json() == "Rick"

from fastapi.testclient import TestClient

from docs_src.events.tutorial003_py39 import (
    app,
    fake_answer_to_everything_ml_model,
    ml_models,
)


def test_events():
    assert not ml_models, "ml_models should be empty"
    with TestClient(app) as client:
        assert ml_models["answer_to_everything"] == fake_answer_to_everything_ml_model
        response = client.get("/predict", params={"x": 2})