Function handler

tests/test_client_middleware.py:36–39

(request: web.Request)

    request_count = 0

    async def handler(request: web.Request) -> web.Response:
        nonlocal request_count
        request_count += 1
        return web.Response(text=f"OK {request_count}")

    async def test_middleware(
        request: ClientRequest, handler: ClientHandlerType