{-# LANGUAGE DataKinds #-}
module InterpreterSpec where

import Category
import Diff
import Data.Record
import Interpreter
import Patch
import Prologue
import Syntax
import Term.Arbitrary
import Test.Hspec
import Test.Hspec.QuickCheck

spec :: Spec
spec = parallel $ do
  describe "interpret" $ do
    it "returns a replacement when comparing two unicode equivalent terms" $
      let termA = cofree $ (StringLiteral .: RNil) :< Leaf ("t\776" :: Text)
          termB = cofree $ (StringLiteral .: RNil) :< Leaf "\7831" in
          diffTerms (free . Free) ((==) `on` extract) diffCost termA termB `shouldBe` free (Pure (Replace termA termB))

    prop "produces correct diffs" $
      \ a b -> let diff = diffTerms (free . Free) ((==) `on` extract) diffCost (toTerm a) (toTerm b) :: Diff Text (Record '[Category]) in
                   (beforeTerm diff, afterTerm diff) `shouldBe` (Just (toTerm a), Just (toTerm b))

    prop "constructs zero-cost diffs of equal terms" $
      \ a -> let term = toTerm a
                 diff = diffTerms (free . Free) ((==) `on` extract) diffCost term term :: Diff Text (Record '[Category]) in
                 diffCost diff `shouldBe` 0