Deprecation warning in TestClient for httpx==0.27.0

[ivanovmg]

As of httpx==0.27.0, the initializer of its Client changed and now passing app kwarg is deprecated.

Minimal working example consists of two files:

main.py

from starlette.applications import Starlette
from starlette.responses import JSONResponse
from starlette.routing import Route


async def homepage(request):
    return JSONResponse({'hello': 'world'})

routes = [
    Route("/", endpoint=homepage)
]

app = Starlette(debug=True, routes=routes)

test_main.py

from main import app
from starlette.testclient import TestClient


client = TestClient(app=app)


def test_ok():
    resp = client.get('/')
    assert resp.status_code == 200

Run:

$ pytest test_main.py

Output:

============================= test session starts =============================
platform win32 -- Python 3.11.4, pytest-8.0.1, pluggy-1.4.0
rootdir: C:\Users\user\temp\starlette-deprecation
plugins: anyio-4.3.0
collected 1 item

test_main.py .                                                           [100%]

============================== warnings summary ===============================
venv\Lib\site-packages\httpx\_client.py:680
  C:\Users\user\temp\starlette-deprecation\venv\Lib\site-packages\httpx\_client.py:680: DeprecationWarning: The 'app' shortcut is now deprecated. Use the explicit style 'transport=WSGITransport(app=...)' instead.
    warnings.warn(message, DeprecationWarning)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
======================== 1 passed, 1 warning in 0.18s =========================

(venv) $ pip list | grep httpx
httpx             0.27.0
(venv) $ pip list | grep starlette
starlette         0.36.3

Refer to httpx PR: encode/httpx#3050

[Kludex]

This is solved on the latest Starlette release.