1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
{-# LANGUAGE OverloadedStrings #-}
module Main where
import Control.Applicative
import Data.Either.Validation
import Data.Monoid (Sum(..))
import Test.QuickCheck (Property, Gen, (===), (.&&.), Arbitrary (..), forAllShrink, oneof)
import Test.Framework (defaultMain)
import Test.Framework.Providers.QuickCheck2 (testProperty)
main :: IO ()
main = defaultMain
[ testProperty "identity" $ identity (<|>) empty genValSumInt shrinkValidation
, testProperty "associativity" $ associativity (<|>) genValSumInt shrinkValidation
]
genValSumInt :: Gen (Validation (Sum Int) (Sum Int))
genValSumInt = genValidation
genValidation :: (Arbitrary a, Arbitrary b) => Gen (Validation a b)
genValidation = oneof
[ fmap Failure arbitrary
, fmap Success arbitrary
]
shrinkValidation :: (Arbitrary a, Arbitrary b) => Validation a b -> [Validation a b]
shrinkValidation (Success x) = Success `fmap` shrink x
shrinkValidation (Failure x) = Failure `fmap` shrink x
-- -- empty is a neutral element
-- empty <|> u = u
-- u <|> empty = u
-- -- (<|>) is associative
-- u <|> (v <|> w) = (u <|> v) <|> w
identity :: (Eq a, Show a) => (a -> a -> a) -> a -> Gen a -> (a -> [a]) -> Property
identity f i gen shr = forAllShrink gen shr $ \x ->
f x i === x .&&. f i x === x
associativity :: (Eq a, Show a) => (a -> a -> a) -> Gen a -> (a -> [a]) -> Property
associativity f gen shr =
forAllShrink gen shr $ \x ->
forAllShrink gen shr $ \y ->
forAllShrink gen shr $ \z ->
f x (f y z) === f (f x y) z
|
