AsyncClient cookie not being persisted

[cp-weng]

# app.py
@router.post("/login")
async def login(response: Response):
    # ...omit
    response.set_cookie(
        key=ACCESS_TOKEN_COOKIE_KEY,
        value=token_value,
    )
    return ...

# conftest.py
@pytest.fixture()
async def async_client(app: FastAPI) -> AsyncGenerator:
    async with AsyncClient(app=app, base_url="http://test") as ac:
        yield ac

# test_blablabla.py
async def test_login(async_client):
    response = await async_client.post("/login", json={...})
    # `response.cookies` is empty here and not being persisted

Expected

As the docs says, response.cookies should contain access token

Actual

response.cookies is empty