module Data.MapSpec where import Data.Map import Test.Hspec spec :: Spec spec = describe "groupBy" $ it "joins all the items whose key is the same" $ groupBy length ["abc", "ab", "a", "atlas", "hades", "orpheus"] `shouldBe` [(1, ["a"]), (2, ["ab"]), (3, ["abc"]), (5, ["hades", "atlas"]), (7, ["orpheus"])]