Sonic is a Scala implementation of hedgehog using Cats and Monix. It is a direct translation of the haskell implementation. It's still in early stage and lacks many parts of the original library but the core data structures are all implemented and working.
- Integrated shrinking, shrinks obey invariants by construction.
- Generators allow monadic effects.
- Range combinators for full control over the scope of generated numbers and collections.
You can find the following example in the subdirectory example.
Import sonic._, cats.syntax.flatMap._ and optionally sonic.syntax._.
import sonic._
import sonic.syntax._
import cats.syntax.flatMap._Once you have your imports set up, you can write a simple property:
def propReverse =
Property(
forAll(Gen.list(Range.linear(0, 100))(Gen.alpha)) >>=
(list => list.reverse.reverse === list)
)Then define a group containing the property that you have just defined:
def listPropertyGroups =
PropertyGroup("example")(
"propReverse" -> propReverse
)Finally, run the property group with Runner.checkGroup:
def main(args: Array[String]): Unit = {
checkGroup(listPropertyGroups)
}and run the Scala program:
$ sbt example/run
━━━ example ━━━
propReverse: trueContributions are welcomed in the form of PRs.
People are expected to follow the Typelevel Code of Conduct when discussing sonic on the Github page, Gitter channel, or other venues.