> - rose tree "integrated shrinking" (eg. Hedgehog) follows the constraints of the generators, but has issues with monadic bind
> - the only approach that seems to magically "just work" is Hypothesis' "internal shrinking", which uses a layer of indirection to shrink lists of random choices instead of the values themselves.
My preferred framework is falsify, which provides "internal integrated shrinking". It's similar to Hypothesis, but uses a tree of generators rather than a linear sequence (it's based on "selective functors", which are a nice interface that's also useful for e.g. validators).
> This library provides property based testing with support for internal integrated shrinking: integrated in the sense of Hedgehog, meaning that there is no need to write a separate shrinker and generator; and internal in the sense of Hypothesis, meaning that this works well even across monadic bind.
I've been talking with Edsko de Vries about Falsify when he was implementing it / writing the paper. Very cool stuff, although somewhat mind-bending :)
> - the only approach that seems to magically "just work" is Hypothesis' "internal shrinking", which uses a layer of indirection to shrink lists of random choices instead of the values themselves.
My preferred framework is falsify, which provides "internal integrated shrinking". It's similar to Hypothesis, but uses a tree of generators rather than a linear sequence (it's based on "selective functors", which are a nice interface that's also useful for e.g. validators).
From https://hackage.haskell.org/package/falsify
> This library provides property based testing with support for internal integrated shrinking: integrated in the sense of Hedgehog, meaning that there is no need to write a separate shrinker and generator; and internal in the sense of Hypothesis, meaning that this works well even across monadic bind.