Property-Based Testing in a Project

What we need now is a framework. As opposed to many testing practices that require a tiny bit of scaffolding and a lot of care, property-based testing is a practice that requires heavy tool assistance. Without a framework, we have no way to generate data, and all we’re left with are encoded rules that don’t get validated. If we use a framework that doesn’t generate great data or doesn’t let us express the ideas we need, it will be very difficult to generate tests of the same quality that we could using a functional framework.

As the course title implies, we will use PropEr. It can be used by both Erlang and Elixir projects and integrate with the usual build tools used in both languages. There are other frameworks available, namely QuickCheck framework by Quviq and Triq. These two frameworks and PropEr are similar enough that if our team is using any of them, we’ll be able to follow along with the text without a problem. This remains true if we’re using Elixir. We might have heard about StreamData, a property-based testing framework exclusive to Elixir. The concepts should not be hard to carry over from framework to framework in any case.

PropEr is usable on its own through either manual calls or command line utils. This is fine for some isolated tests and quick demos, but it’s usually nicer to be able to get the framework to fit our everyday development workflow instead.