Library based off the Haskell QuickCheck making heavy use of Implicits.

The user could write something like:

test_commutativity (x : int) (y : int) = x + y = y + x
let () = quickCheck test_commutativity

And it will respond with either:

Success: {num_tests: 1000}

Or

Failure: {num_tests: 0, used_seed: 650494855, failing_case: {ok: false, expect: true, reason: "Falsifiable", test_case: "(936052328) (129383761)", the_exception: None}}

Quickcheck will also catch exceptions and report them with the relevant test cases:

Failure: {num_tests: 0, used_seed: 275906564, failing_case: {ok: false, expect: true, reason: "", test_case: "(())", the_exception: Dune__exe__Test.Not_Implemented}}

For custom types, that do not have an Arbitrary instance, it is easiest to provide the Generics implementation of the type, as that provides a default Arbitrary implementation.