I’m happy to share release 0.2 of
qcheck-stm for black-box property-based testing.
qcheck-linrequires little more than an interface description. It allows to test a library for sequential consistency, that is, whether results obtained from using it in parallel agree with some linear, single domain execution.
qcheck-stmis a model-based, state-machine framework for both sequential and parallel testing. It allows to test an imperative interface against a pure model description, and thereby allows to express and test intended behaviour beyond a signature description.
For example, here’s a minimal
qcheck-lin test of a selection of the
module HashtblSig = struct type t = (char, int) Hashtbl.t let init () = Hashtbl.create ~random:false 42 let cleanup _ = () open Lin let a,b = char_printable,nat_small let api = [ val_ "Hashtbl.add" Hashtbl.add (t @-> a @-> b @-> returning unit); val_ "Hashtbl.remove" Hashtbl.remove (t @-> a @-> returning unit); val_ "Hashtbl.find" Hashtbl.find (t @-> a @-> returning_or_exc b); val_ "Hashtbl.mem" Hashtbl.mem (t @-> a @-> returning bool); val_ "Hashtbl.length" Hashtbl.length (t @-> returning int); ] end module HT = Lin_domain.Make(HashtblSig) ;; QCheck_base_runner.run_tests_main [ HT.lin_test ~count:1000 ~name:"Hashtbl DSL test"; ]
Running this test quickly finds a minimal counterexample to illustrate that
Hashtbl is not safe to use in parallel:
Messages for test Hashtbl DSL test: Results incompatible with sequential execution | Hashtbl.add t '<' 0 : () | .------------------------------------. | | Hashtbl.add t 'a' 0 : () Hashtbl.remove t '<' : () Hashtbl.length t : 0
We presented preliminary work on both these libraries at the OCaml Workshop 2022. The libraries furthermore underlie our continuing effort to test the multicore runtime of OCaml 5.x, and have helped identify several issues.
The 0.2 release adds a range of features and bugfixes, including support for OCaml 4.12.x, 4.13.x and 4.14.x without the
Detailed release notes and more information is available from the GitHub repository:
GitHub - ocaml-multicore/multicoretests: PBT testsuite and libraries for testing multicore OCaml