We are witnessing a resurgence of decentralized systems whose nodes communicate through open, symmetric protocols. For example, the Fediverse, the open social media network built around the ActivityPub standard, has been growing substantially in recent years.

However, quality control of such systems using complex protocols like ActivityPub is difficult. How do you test your own application against others, each of which might take a couple of hours simply to install?

Enter FediTest, an open-source project building a test framework for testing these kinds of systems, and a test suite for the Fediverse. We will describe the problem as we see it, explain our approach, and demo live tests.