parsec解析器的有趣的Hunit测试？

import Test.HUnit
import Text.Parsec

-- 定义解析器
integerParser :: Parsec String () Integer
integerParser = read <$> many1 digit

-- 测试解析整数
testParseInteger :: Test
testParseInteger = TestCase $
  assertEqual "解析整数" (Right 123) (parse integerParser "" "123")

-- 测试解析字符串
testParseString :: Test
testParseString = TestCase $
  assertEqual "解析字符串" (Right "hello") (parse (string "hello") "" "hello")

-- 测试解析器组合
testParseCombination :: Test
testParseCombination = TestCase $
  assertEqual "解析器组合" (Right (123, "hello")) (parse ((,) <$> integerParser <*> string "hello") "" "123hello")

-- 测试套件
parserTests :: Test
parserTests = TestList [TestLabel "testParseInteger" testParseInteger,
                        TestLabel "testParseString" testParseString,
                        TestLabel "testParseCombination" testParseCombination]

-- 运行测试
main :: IO Counts
main = runTestTT parserTests