Property-Based Testing with PropEr, Erlang, and Elixir

Chapter 5Responsible Testing

A common sight in a team that just started learning property-based testing is that almost all the new tests written are properties, even when it doesn’t really make sense to do so. The pendulum swings too far and too fast, and the project suffers for it. In this chapter, we’ll see multiple example situations where property tests may or may not be appropriate, how they can be enhanced through careful addition of traditional tests in a regular project or other external tool like Dialyzer, or where they may be just plain inappropriate. We’ll move from knowing how properties work—you can write generators, measure their efficiency, and come up with properties through various strategies—to having a good feel of when