| module Pair where | |
| import Effect | |
| import Prelude | |
| import Data.Eq (class Eq1) | |
| import Test.QuickCheck.Arbitrary (class Arbitrary, arbitrary) | |
| import Test.QuickCheck.Laws (checkLaws) | |
| import Test.QuickCheck.Laws.Data.Functor (checkFunctor) | |
| data Pair a = Pair a a | |
| derive instance eq1Pair :: Eq1 Pair | |
| derive instance eqPair :: Eq a => Eq (Pair a) | |
| instance arbPair :: Arbitrary a => Arbitrary (Pair a) where | |
| arbitrary = Pair <$> arbitrary <*> arbitrary | |
| instance functorPair :: Functor Pair where | |
| map f (Pair x y) = Pair (f x) (f y) | |
| prxPair :: Proxy2 Pair | |
| prxPair = Proxy2 | |
| main :: Effect Unit | |
| main = do checkLaws "Pair" (checkFunctor prxPair) | |
| {- | |
| Or, in the repl (if you don't want to define `main`): | |
| > import Prelude | |
| > import Test.QuickCheck.Laws | |
| > import Test.QuickCheck.Laws.Data.Functor | |
| > import Pair | |
| > checkLaws "Pair" (checkFunctor prxPair) | |
| Checking laws of Pair instances... | |
| Checking 'Identity' law for Functor | |
| 1000/1000 test(s) passed. | |
| Checking 'Composition' law for Functor | |
| 1000/1000 test(s) passed. | |
| unit | |
| > -- Also works (without checkLaws): | |
| > checkFunctor prxPair | |
| Checking 'Identity' law for Functor | |
| 1000/1000 test(s) passed. | |
| Checking 'Composition' law for Functor | |
| 1000/1000 test(s) passed. | |
| unit | |
| -} |
GitHub code search for purescript-quickcheck-laws (a good way to search for repos that are using the library in code / a good way to find concrete implementations in code).
Test.QuickCheck.Laws on Pursuit
purescript-quickcheck-laws on GitHub
Sample code containing more tests based on Test.QuickCheck.Laws