The `TestClient` does some magic inside to call the asynchronous FastAPI application in your normal `def` test functions, using standard pytest. But that magic doesn't work anymore when we're using it inside asynchronous functions. By running our tests asynchronously, we can no longer use the `TestClient` inside our test functions.

import importlib

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_01_py39"),
        pytest.param("tutorial001_01_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):

    async def read_root() -> Any:
        return {"$ref": "some-ref"}

    client = TestClient(app)
    return client


def test_get(client: TestClient):
    response = client.get("/")
    assert response.json() == {"$ref": "some-ref"}


def test_openapi_schema(client: TestClient):
    response = client.get("openapi.json")
    assert response.json() == snapshot(
        {

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial001b_py39 import app

client = TestClient(app)


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


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

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial005_py39 import app

client = TestClient(app)


def test_get():
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert response.text == "Hello World"


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

import gzip
import importlib
import json

import pytest
from fastapi import Request
from fastapi.testclient import TestClient

from tests.utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_an_py39"),
        pytest.param("tutorial001_an_py310", marks=needs_py310),

from typing import Annotated, Union

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel


@pytest.fixture(name="client")
def client_fixture() -> TestClient:
    from fastapi import Body
    from pydantic import Discriminator, Tag

    class Cat(BaseModel):
        pet_type: str = "cat"

import pytest
from fastapi.testclient import TestClient

from tests.utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.dataclasses_.{request.param}")

    client = TestClient(mod.app)

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial006_py39 import app

client = TestClient(app)


def test_get():
    response = client.get("/typer", follow_redirects=False)
    assert response.status_code == 307, response.text
    assert response.headers["location"] == "https://typer.tiangolo.com"


def test_openapi_schema():
    response = client.get("/openapi.json")

from fastapi import FastAPI
from fastapi.testclient import TestClient

from .utils import needs_py310


@needs_py310
def test_typing():
    types = {
        list[int]: [1, 2, 3],
        dict[str, list[int]]: {"a": [1, 2, 3], "b": [4, 5, 6]},
        set[int]: [1, 2, 3],  # `set` is converted to `list`
        tuple[int, ...]: [1, 2, 3],  # `tuple` is converted to `list`
    }
    for test_type, expect in types.items():