Test Read/Show instances

Author: knrafto

tests/HashMapProperties.hs

@@ -21,7 +21,7 @@ import Test.Framework.Providers.QuickCheck2 (testProperty)
 
 -- Key type that generates more hash collisions.
 newtype Key = K { unK :: Int }
-            deriving (Arbitrary, Eq, Ord, Show)
+            deriving (Arbitrary, Eq, Ord, Read, Show)
 
 instance Hashable Key where
     hashWithSalt salt k = hashWithSalt salt (unK k) `mod` 20
@@ -38,6 +38,9 @@ pEq xs = (M.fromList xs ==) `eq` (HM.fromList xs ==)
 pNeq :: [(Key, Int)] -> [(Key, Int)] -> Bool
 pNeq xs = (M.fromList xs /=) `eq` (HM.fromList xs /=)
 
+pReadShow :: [(Key, Int)] -> Bool
+pReadShow xs = M.fromList xs == read (show (M.fromList xs))
+
 pFunctor :: [(Key, Int)] -> Bool
 pFunctor = fmap (+ 1) `eq_` fmap (+ 1)
 
@@ -192,6 +195,7 @@ tests =
       testGroup "instances"
       [ testProperty "==" pEq
       , testProperty "/=" pNeq
+      , testProperty "Read/Show" pReadShow
       , testProperty "Functor" pFunctor
       , testProperty "Foldable" pFoldable
       ]

tests/HashSetProperties.hs

@@ -16,7 +16,7 @@ import Test.Framework.Providers.QuickCheck2 (testProperty)
 
 -- Key type that generates more hash collisions.
 newtype Key = K { unK :: Int }
-            deriving (Arbitrary, Enum, Eq, Integral, Num, Ord, Show, Real)
+            deriving (Arbitrary, Enum, Eq, Integral, Num, Ord, Read, Show, Real)
 
 instance Hashable Key where
     hashWithSalt salt k = hashWithSalt salt (unK k) `mod` 20
@@ -33,6 +33,9 @@ pEq xs = (Set.fromList xs ==) `eq` (S.fromList xs ==)
 pNeq :: [Key] -> [Key] -> Bool
 pNeq xs = (Set.fromList xs /=) `eq` (S.fromList xs /=)
 
+pReadShow :: [Key] -> Bool
+pReadShow xs = Set.fromList xs == read (show (Set.fromList xs))
+
 pFoldable :: [Int] -> Bool
 pFoldable = (L.sort . Foldable.foldr (:) []) `eq`
             (L.sort . Foldable.foldr (:) [])
@@ -111,6 +114,7 @@ tests =
       testGroup "instances"
       [ testProperty "==" pEq
       , testProperty "/=" pNeq
+      , testProperty "Read/Show" pReadShow
       , testProperty "Foldable" pFoldable
       ]
     -- Basic interface