hypothesis.works articles: Rule Based Stateful Testing

Hypothesis’s standard testing mechanisms are very good for testing things that can be considered direct functions of data. But supposed you have some complex stateful system or object that you want to test. How can you do that?

In this article we’ll see how to use Hypothesis’s rule based state machines to define tests that generate not just simple data, but entire programs using some stateful object. These will give the same level of boost to testing the behaviour of the object as you get to testing the data it accepts.