Miguel is passionate about teaching, developers' communities and everything related to Net.Net. In this article, we'll go over property-based testing, an alternative approach to unit testing. Property-based tests deal with all the shortcomings of example-based and brittle tests. The best approach is to have the right mix of the two in your test suite. The first thing to do is to represent the relationship between inputs and outputs to express deterministic expected results. With these, it's impossible to write an implementation of the Add method that doesn't behave properly.