It seems to provide random data generation only.
I'd say _the_ feature of QuickCheck is minimisation of the counter example.
I'd say _the_ feature of QuickCheck is minimisation of the counter example.
It's a lot more fully featured than the alternatives. It still lacks a few features of quickcheck (coarbitrary for function generation, labelling of examples), but it does example minimization and a whole bunch of things even quickcheck doesn't.
Hypothesis escaped our search. I don't know how but the project could do with better Google ranking :)
It has some really useful features like storing the counterexamples.
The CLA is a bit odd but I'm sure you have good reasons!
The CLA is for a mix of weird personal reasons around open source and cynically practical ones. Hypothesis is 100% always going to remain free, but I'm trying to figure out ways that I can make money out of working on it (I've put a ton of work into it, so it would be a shame not to) and that's a lot easier if I retain the copyright. I may decide it's not useful and drop it later, but it's a lot easier to have it now and drop it later than it is to try and retroactively get one if it turns out I need it.