added tasty + hedgehog property test infrastucture with a few simple tests

shell.nix

@@ -0,0 +1,11 @@
+{ghc}:
+with (import <nixpkgs> {});
+
+haskell.lib.buildStackProject {
+  inherit ghc;
+  name = "myEnv";
+  buildInputs = [ zlib binutils gmp];
+  buildPhase = ''
+    export LANG=en_US.UTF-8
+    '';
+}

stack.yaml

@@ -1,4 +1,10 @@
 resolver: lts-10.4
 
 nix:
-  packages: [binutils, gmp]
+  enable: true
+  shell-file: shell.nix
+
+extra-deps:
+- tasty-0.12.0.1
+
+allow-newer: true

test/Spec.hs

@@ -0,0 +1,9 @@
+module Main where
+
+import Test.Tasty (defaultMain, testGroup)
+
+import Test.Universum.Property (hedgehogTestTree)
+
+main :: IO ()
+main = do
+    defaultMain hedgehogTestTree

test/Test/Universum/Property.hs

@@ -0,0 +1,104 @@
+
+module Test.Universum.Property
+        ( hedgehogTestTree
+        ) where
+
+import Universum
+import Hedgehog
+import Test.Tasty
+import Test.Tasty.Hedgehog
+
+import qualified Hedgehog.Gen              as Gen
+import qualified Hedgehog.Range            as Range
+
+import qualified Data.ByteString           as B
+import qualified Data.ByteString.Lazy      as LB
+import qualified Data.ByteString.Lazy.UTF8 as LBU
+import qualified Data.ByteString.UTF8      as BU
+import qualified Data.Text                 as T
+import qualified Data.Text.Encoding        as T
+import qualified Data.Text.Encoding.Error  as T
+import qualified Data.Text.Lazy            as LT
+import qualified Data.Text.Lazy.Encoding   as LT
+
+import Data.List (nub)
+
+
+hedgehogTestTree :: TestTree
+hedgehogTestTree = testGroup "Tests" [utfProps, listProps, boolMProps]
+
+utfProps :: TestTree
+utfProps = testGroup "utf8 conversion property tests" 
+    [ testProperty "String to ByteString invertible" prop_StringToBytes
+    , testProperty "Text to ByteString invertible" prop_TextToBytes
+    , testProperty "ByteString to Text or String invertible" prop_BytesTo
+    ]
+
+utf8String :: Gen String
+utf8String = Gen.string (Range.linear 0 10000) Gen.unicode
+
+utf8Text :: Gen T.Text
+utf8Text = Gen.text (Range.linear 0 10000) Gen.unicode
+
+utf8Bytes :: Gen B.ByteString
+utf8Bytes = Gen.utf8 (Range.linear 0 10000) Gen.unicode
+
+-- "\65534" fails, but this is from BU.toString
+-- > BU.toString (BU.fromString "\65534") == "\65533"
+
+prop_StringToBytes :: Property
+prop_StringToBytes = property $ do
+    str <- forAll utf8String
+    assert $ str == (decodeUtf8 (encodeUtf8 str :: B.ByteString))
+          && str == (decodeUtf8 (encodeUtf8 str :: LB.ByteString))
+
+
+prop_TextToBytes :: Property
+prop_TextToBytes = property $ do
+    txt <- forAll utf8Text
+    assert $ txt == (decodeUtf8 (encodeUtf8 txt :: B.ByteString))
+          && txt == (decodeUtf8 (encodeUtf8 txt :: LB.ByteString))
+
+-- "\239\191\190" fails, but this is the same as "\65534" :: String
+prop_BytesTo :: Property
+prop_BytesTo = property $ do
+    utf <- forAll utf8Bytes
+    assert $ utf == (encodeUtf8 (decodeUtf8 utf :: String))
+          && utf == (encodeUtf8 (decodeUtf8 utf :: T.Text))
+          && utf == (encodeUtf8 (decodeUtf8 utf :: LT.Text))
+
+-- ordNub
+
+listProps :: TestTree
+listProps = testGroup "list function property tests" 
+    [ testProperty "Hedgehog ordNub xs == nub xs" prop_ordNubCorrect
+    ]
+
+genIntList :: Gen [Int]
+genIntList = Gen.list (Range.linear 0 10000) Gen.enumBounded
+
+prop_ordNubCorrect :: Property
+prop_ordNubCorrect = property $ do
+    xs <- forAll genIntList
+    ordNub xs === Data.List.nub xs
+
+-- logicM
+
+genBoolList :: Gen [Bool]
+genBoolList = Gen.list (Range.linear 0 1000) Gen.bool
+
+boolMProps :: TestTree
+boolMProps = testGroup "lifted logic function property tests"
+    [ testProperty "Hedgehog andM" prop_andM
+    , testProperty "Hedgehog orM" prop_orM
+    ]
+
+prop_andM :: Property
+prop_andM = property $ do
+    bs <- forAll genBoolList
+    andM (return <$> bs) === ((return $ Universum.and bs) :: Maybe Bool)
+
+prop_orM :: Property
+prop_orM = property $ do
+    bs <- forAll genBoolList
+    orM (return <$> bs) === ((return $ Universum.or bs) :: Maybe Bool)

universum.cabal

@@ -91,6 +91,25 @@ library
   default-extensions:  NoImplicitPrelude
                        OverloadedStrings
 
+test-suite universum-test
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+
+  other-modules:       Test.Universum.Property
+
+  build-depends:       base             >= 4.8 && < 5
+                     , universum
+                     , bytestring
+                     , text
+                     , utf8-string
+                     , hedgehog         ^>= 0.5.1
+                     , tasty            ^>= 0.12
+                     , tasty-hedgehog   ^>= 0.1
+
+  ghc-options:         -Wall -threaded
+  default-language:    Haskell2010
+
 test-suite universum-doctest
   type:                exitcode-stdio-1.0
   hs-source-dirs:      test