This is awesome, I'm excited to see more attention being paid to property-based testing, and MacIver deserves to be rewarded and supported for his past and ongoing work on Hypothesis.
When I first encountered property-based testing, I had some trouble coming up with interesting properties to test, since I was so used to thinking in terms of individual test cases. This blogpost surveys some great starting points for identifying useful properties to test: https://fsharpforfunandprofit.com/posts/property-based-testi...