from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI(swagger_ui_oauth2_redirect_url=None)


@app.get("/items/")
async def read_items():
    return {"id": "foo"}


client = TestClient(app)


def test_swagger_ui():
    response = client.get("/docs")
    assert response.status_code == 200, response.text
    assert response.headers["content-type"] == "text/html; charset=utf-8"

from fastapi.testclient import TestClient

from docs_src.metadata.tutorial002_py39 import app

client = TestClient(app)


def test_items():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [{"name": "Foo"}]


def test_get_openapi_json_default_url():
    response = client.get("/openapi.json")
    assert response.status_code == 404, response.text

from fastapi import Depends, FastAPI
from fastapi.requests import HTTPConnection
from fastapi.testclient import TestClient
from starlette.websockets import WebSocket

app = FastAPI()
app.state.value = 42


async def extract_value_from_http_connection(conn: HTTPConnection):
    return conn.app.state.value


@app.get("/http")
async def get_value_by_http(value: int = Depends(extract_value_from_http_connection)):
    return value

import importlib

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial008b_py39"),
        pytest.param("tutorial008b_an_py39"),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.dependencies.{request.param}")

    client = TestClient(mod.app)
    return client

import functools

from fastapi import FastAPI
from fastapi.testclient import TestClient

from .forward_reference_type import forwardref_method


def passthrough(f):
    @functools.wraps(f)
    def method(*args, **kwargs):
        return f(*args, **kwargs)

    return method


def test_wrapped_method_type_inference():
    """
    Regression test ensuring that when a method imported from another module

from fastapi import FastAPI
from fastapi.testclient import TestClient

swagger_ui_oauth2_redirect_url = "/docs/redirect"

app = FastAPI(swagger_ui_oauth2_redirect_url=swagger_ui_oauth2_redirect_url)


@app.get("/items/")
async def read_items():
    return {"id": "foo"}


client = TestClient(app)


def test_swagger_ui():
    response = client.get("/docs")
    assert response.status_code == 200, response.text

{* ../../docs_src/app_testing/tutorial004_py39.py hl[9:15,18,27:28,30:32,41:43] *}


You can read more details about the ["Running lifespan in tests in the official Starlette documentation site."](https://www.starlette.dev/lifespan/#running-lifespan-in-tests)

For the deprecated `startup` and `shutdown` events, you can use the `TestClient` as follows:

from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial006_py39 import app

client = TestClient(app)


def test_post():
    response = client.post("/items/", content=b"this is actually not validated")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "size": 30,
        "content": {
            "name": "Maaaagic",
            "price": 42,

import importlib
from types import ModuleType
from unittest.mock import patch

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(
    name="mod",
    params=[
        pytest.param("tutorial004_py39"),
        pytest.param("tutorial004_py310", marks=needs_py310),
        pytest.param("tutorial004_an_py39"),
        pytest.param("tutorial004_an_py310", marks=needs_py310),

El `TestClient` hace algo de magia interna para llamar a la aplicación FastAPI asíncrona en tus funciones de test `def` normales, usando pytest estándar. Pero esa magia ya no funciona cuando lo usamos dentro de funciones asíncronas. Al ejecutar nuestros tests de manera asíncrona, ya no podemos usar el `TestClient` dentro de nuestras funciones de test.