Use variations of the same input to facilitate understanding

chYou can simplify your understanding of the different test cases by using the same input seed for all of them, as we noticed in an observational study with professional developers described in my paper with Treude and Zaidman (2021). For each partition, you then make small modifications to the input seed: just enough to meet the criteria of that partition. Example, all the test cases are based on the string “abc”; as soon as one test case fails, it is easy to compare it to similar inputs from other test cases that pass.

Note that this trick goes against the common testing idea of varying inputs as much as possible. Varying inputs is essential, as it allows us to explore the input space and identify corner cases. However, when doing specification-based testing, I prefer to focus on rigorously identifying and testing partitions. We will write test cases that explore the input domain in an automated fashion via property-based testing