Twisted has been supporting asynchronous / event driven applications way before asyncio. Twisted, and Glyph, have also been encouraging automated tests for a very long time. Twisted uses a technique that should be usable by other applications, even those using asyncio or other event driven architectures. Full Transcript (https://pythontest.com/testandcode/184-twisted-testing-event-driven-async-apps/) Special Guest: Glyph.