A framework-agnostic library for testing ASGI web applications




Build Status PyPI version Codcov

Async ASGI TestClient is a library for testing web applications that implements ASGI specification (version 2 and 3).

The motivation behind this project is building a common testing library that doesn't depend on the web framework (Quart, Startlette, ...).

It works by calling the ASGI app directly. This avoids the need to run the app with a http server in a different process/thread/asyncio-loop. Since the app and test run in the same asyncio loop, it's easier to write tests and debug code.

This library is based on the testing module provided in Quart.


Requirements: Python 3.6+


pip install async-asgi-testclient


from quart import Quart, jsonify

app = Quart(__name__)

async def root():
    return "plain response"

async def json():
    return jsonify({"hello": "world"})

if __name__ == '__main__':

from async_asgi_testclient import TestClient

import pytest

async def test_quart_app():
    from .my_api import app

    async with TestClient(app) as client:
        resp = await client.get("/")
        assert resp.status_code == 200
        assert resp.text == "plain response"

        resp = await client.get("/json")
        assert resp.status_code == 200
        assert resp.json() == {"hello": "world"}


  • cookies
  • multipart/form-data
  • follow redirects
  • response streams
  • request streams
  • websocket support