import           Control.Arrow
import           Data.Dependency
import qualified Data.Map        as M
import qualified Data.Set        as S
import           Test.Hspec

free :: Dependency
free = Dependency "free" mempty mempty

comonad :: Dependency
comonad = Dependency "comonad" mempty mempty

lens :: Dependency
lens = Dependency "lens" mempty ["free", "comonad"]

deps :: [Dependency]
deps = [free, lens, comonad]

mapSingles :: [(d, b)] -> [(d, S.Set b)]
mapSingles = fmap (second S.singleton)

set :: PackageSet Dependency
set = PackageSet $ M.fromList (mapSingles [("lens", lens), ("comonad", comonad), ("free", free)])

main :: IO ()
main = hspec $ parallel $ do
    describe "buildSequence" $
        it "correctly orders dependencies" $
            buildSequence deps `shouldBe` [[free, comonad], [lens]]
    describe "resolveDependencies" $
        it "correctly resolves dependencies in a package set" $
            resolveDependencies set (buildSequence [lens]) `shouldBe` Just [[free, comonad], [lens]]