Make 'PropertyT' an instance of 'MonadResource'

[geigerzaehler]

Make PropertyT an instance of MonadResource simplifies writing tests that use the functions with a MonadResource constraint. See the changed example for instance.

[jacobstanley]

This is awesome, I didn't have this from the beggining because, I think I thought ResourceT wouldn't work on the inside, i.e. hoist and I wasn't clever enough to get ResourceT to work on the outside of GenT.

See the recent PR #255

I updated the PR with a fix for 7.10.

[jacobstanley]

It's funny the only reason the TestT / PropertyT separation even exists is for ResourceT support, maybe I should merge PropertyT and TestT like it used to be...

[geigerzaehler]

Thanks for merging! This is going to make my life a lot easier.

[MichaelXavier]

Given that recent versions of ResourceT require MonadUnliftIO, which forbids instances in stateful monads, is this even possible to use anymore? I've got a test where I'd like to interleave some assertions with a ResourceT so I don't get too far in the test if something is wrong and I'm not seeing a way how. I might have to fall back to removing ResourceT entirely and using bracket.

[HuwCampbell]

So I believe that the example is now quite dangerous.

prop_unix_sort :: Property
property . hoist runResourceT $ do
    (_, dir) <- Temp.createTempDirectory Nothing "prop_dir"
    doStuff

If I understand correctly, this will create a directory for every shrink and not clean them up until all shrinking is complete. As shrinking can run hundreds or thousands of times, we will have that many temporary directories on the system; and if it was instead file handles, it could crash the system.

EDIT: Apologies, I see you've addressed this in #285