ToJSON.hs

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE TemplateHaskell #-}
{-# OPTIONS_GHC -Wno-orphans #-}

module Tests.Object.ToJSON where

import Data.Aeson (FromJSON(..), ToJSON(..))
import qualified Data.Aeson.Types as Aeson
import Test.Tasty
import Test.Tasty.QuickCheck

import TestUtils (parseProxy)
import TestUtils.Arbitrary (ArbitraryObject(..), forAllArbitraryObjects)

test :: TestTree
test = testGroup "ToJSON instance"
  [ testProperty "parseJSON . toJSON === pure" $
      $(forAllArbitraryObjects) $ \(ArbitraryObject proxy v _) ->
        let o = either error id $ parseProxy proxy v
        in (parseJSON . toJSON) o === pure o
  ]

{- Realizing Aeson.Parser -}

-- We're defining two Parsers to be equivalent if they evaluate to the same result.
instance Eq a => Eq (Aeson.Parser a) where
  a == b = runParser a == runParser b

instance Show a => Show (Aeson.Parser a) where
  show = show . runParser

runParser :: Aeson.Parser a -> Aeson.Result a
runParser = Aeson.parse id