Add hunit and hegdehog test suite with roundtrip test for patchThatChangesMap

Author: maralorn

patch.cabal

@@ -64,6 +64,19 @@ library
     build-depends: these >= 0.4 && <0.9
                  , monoidal-containers == 0.4.0.0
 
+test-suite tests
+  default-language: Haskell2010
+  type: exitcode-stdio-1.0
+  main-is: tests.hs
+  hs-source-dirs: test
+  build-depends: base
+               , patch
+               , containers
+               , hedgehog
+               , HUnit
+  if impl(ghcjs)
+    buildable: False
+
 test-suite hlint
   default-language: Haskell2010
   type: exitcode-stdio-1.0

test/tests.hs

@@ -0,0 +1,43 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Main where
+
+import Test.HUnit (runTestTT, (~:), assertEqual, errors, failures, test)
+import Data.Patch ( Patch(apply) )
+import Data.Patch.MapWithMove ( patchThatChangesMap )
+import Data.Map as Map ( Map, fromList, singleton )
+import Hedgehog (checkParallel, discover, Property, property, forAll, PropertyT, (===))
+import Hedgehog.Gen as Gen ( int )
+import Hedgehog.Range as Range ( linear )
+import Control.Monad (replicateM)
+import System.Exit (exitFailure, exitSuccess)
+import Data.Sequence as Seq ( foldMapWithIndex, replicateM )
+
+main :: IO ()
+main = do
+   counts <- runTestTT $ test [
+      "Simple Move" ~: (do
+         let mapBefore = Map.fromList [(0,1)]
+             mapAfter = Map.fromList [(0,0),(1,1)]
+             patch = patchThatChangesMap mapBefore mapAfter
+             afterPatch = apply patch mapBefore
+         assertEqual "Patch creates the same Map" (Just mapAfter) afterPatch),
+      "Property Checks" ~: propertyChecks
+    ]
+   if errors counts + failures counts == 0 then exitSuccess else exitFailure
+
+propertyChecks :: IO Bool
+propertyChecks = checkParallel $$(discover)
+
+prop_patchThatChangesMap :: Property
+prop_patchThatChangesMap = property $ do
+   mapBefore <- makeRandomIntMap
+   mapAfter <- makeRandomIntMap
+   let patch = patchThatChangesMap mapBefore mapAfter
+   Just mapAfter === apply patch mapBefore
+
+makeRandomIntMap :: Monad m => PropertyT m (Map Int Int)
+makeRandomIntMap = do
+   let genNum = Gen.int (Range.linear 0 100)
+   length <- forAll genNum
+   listOfNumbers <- forAll $ Seq.replicateM length genNum
+   pure $ Seq.foldMapWithIndex Map.singleton listOfNumbers