如何在 Haskell Tasty 测试中捕获 stdout 并模拟 stdin？

问：

我的不纯函数定义如下：

module HangmanImpure (HangmanImpure.getLine, HangmanImpure.putStr, HangmanImpure.putStrLn, HangmanImpure.strlen) where

import qualified System.IO as Sys

getLine :: IO String
getLine = do x <- Sys.getChar
             if x == '\n' then
                 return []
             else
                do xs <- HangmanImpure.getLine
                   return (x:xs)

putStr :: String -> IO ()
putStr [] = return ()
putStr (x:xs) = do Sys.putChar x
                   HangmanImpure.putStr xs

我想使用 Tasty 测试这些功能，例如：

module TestHangmanImpure (scProps) where

import qualified Test.Tasty as T
import qualified Test.Tasty.SmallCheck as SC

import qualified HangmanImpure as HI (getLine, putStr, putStrLn, strlen)

scProps :: T.TestTree
scProps = T.testGroup "checked by SmallCheck"
    [
        SC.testProperty "getLine should return what is written to stdin" $
            "Placeholder to get the test to run" == "Placeholder to get the test to run" -- HI.getLine == IO "Hello" -- PLEASE, HELP ME WITH SOME CONTENT HERE

        , SC.testProperty "putStr should write to stdout what it gets in as an argument" $
            "Placeholder to get the test to run" == "Placeholder to get the test to run" -- HI.putStr "Nice day!" -- PLEASE, HELP ME WITH SOME CONTENT HERE
    ]

如果有人能在我指出的两个简单测试中填写身体，我将不胜感激。

编辑： 我认为[在 haskell 中，我如何与 stdin 的交互？[1] 可以引导我找到解决方案。我可以让该解决方案在我的 Win10 上使用 HSpec。所以这个问题几乎是重复的。但是我无法使用 Tasty.HUnit 让它工作。我的暂定代码运行如下：IO ()

module TestUtilImpure (scProps, qcProps, uTests, properties) where
    
import qualified Test.Tasty as T
import qualified Test.Tasty.HUnit as HU
    
import StdInStdOutUtil as IOU (captureStdout, provideStdin)
import UtilImpure as UI (getLine)
    
properties :: T.TestTree
properties = T.testGroup "TestUtilImpure tests" [
          uTests
        ]
    
uTests :: T.TestTree
uTests = T.testGroup "Checked by HUnit"
        [
            HU.testCase "UI.getLine reading from stdin should return what was provided" $ do
                let line = "Hello, echo!\n"
                let capturedIOString = IOU.captureStdout (provideStdin line echo)
                capturedString <- capturedIOString
                HU.assertBool "The String returned from UI.getLine differs from the one provided for StdIn" $ capturedString == line
        ]

echo :: IO ()
echo = UI.getLine >>= Prelude.putStrLn

（我把 [1] 中的解决方案：在 haskell 中，我如何与“IO（）”的 stdin 交互？

 import StdInStdOutUtil as IOU (captureStdout, provideStdin)

我的测试失败：

从 UI.getLine 返回的 String 与为 标准输入

无论我测试 Prelude.getLine 还是我自己的 UI.getLine，我都会收到相同的错误消息。所以我想有一些我不理解的语法使用 Tasty 失败了。