megaparsec/tests/Char.hs

-- -*- Mode: Haskell; -*-
--
-- QuickCheck tests for Megaparsec's character parsers.
--
-- Copyright © 2015 Megaparsec contributors
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are
-- met:
--
-- * Redistributions of source code must retain the above copyright notice,
--   this list of conditions and the following disclaimer.
--
-- * Redistributions in binary form must reproduce the above copyright
--   notice, this list of conditions and the following disclaimer in the
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--
-- This software is provided by the copyright holders "as is" and any
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module Char (tests) where

import Data.Char (isSpace)
import Data.List (findIndex)

import Test.Framework
import Test.QuickCheck
import Test.Framework.Providers.QuickCheck2 (testProperty)

import Text.Megaparsec.Char
import Text.Megaparsec.Combinator
import Text.Megaparsec.Error
import Text.Megaparsec.Pos
import Text.Megaparsec.Prim

import Util

tests :: Test
tests = testGroup "Character parsers"
        [ testProperty "oneOf" prop_oneOf
        , testProperty "noneOf" prop_noneOf
        , testProperty "spaces" prop_spaces ]

prop_oneOf :: String -> String -> Property
prop_oneOf s a = checkParser (oneOf a) s r
    where h = head s
          r | null s = posErr 0 s [suneStr ""]
            | length s == 1 && h `elem` a = Right h
            | h `notElem` a = posErr 0 s [suneCh h]
            | otherwise = posErr 1 s [uneCh (s !! 1), exStr ""]

prop_noneOf :: String -> String -> Property
prop_noneOf s a = checkParser (noneOf a) s r
    where h = head s
          r | null s = posErr 0 s [suneStr ""]
            | length s == 1 && h `notElem` a = Right h
            | h `elem` a = posErr 0 s [suneCh h]
            | otherwise = posErr 1 s [uneCh (s !! 1), exStr ""]

prop_spaces :: String -> Property
prop_spaces s = checkParser spaces s r
    where r = case findIndex (not . isSpace) s of
                Just x  ->
                    let ch = s !! x
                    in posErr x s
                           [ suneCh ch
                           , uneCh  ch
                           , exSpec "white space"
                           , exStr "" ]
                Nothing -> Right ()