Reusable specifications
(similar in spirit to checkers)
Check Monoid laws
shouldSatisfyMonoidLaws can be used to specify, that a given type should
satisfy the Monoid laws.
-- file Spec.hs
import Test.Hspec
import Test.Hspec.Laws
main :: IO ()
main = hspec $ do
describe "List as a Monoid" $
shouldSatisfyMonoidLaws (undefined :: [Int])Running this produces a nice spec.
$ runhaskell Spec.hs
List as a Monoid
mempty
- is a left identity
- is a right identity
mappend
- is associative
Finished in 0.1142 seconds
3 examples, 0 failures