Clone git repo in temporary directory and do `ls-files`

clone.hs

import           Control.Exception (bracket_)
import           System.Directory
import           System.Exit       (ExitCode)
import           System.IO.Temp    (withSystemTempDirectory)
import           System.Process    (system)

inTemporaryDirectory :: String -> IO a -> IO a
inTemporaryDirectory name cb =
    withSystemTempDirectory name $ flip inDirectory cb

inDirectory :: FilePath -> IO a -> IO a
inDirectory path cb = do
    pwd <- getCurrentDirectory
    bracket_ (setCurrentDirectory path) (setCurrentDirectory pwd) cb

cloneRepo :: String -> IO ExitCode
cloneRepo repoUrl = do
    system $ "git clone --no-checkout --depth=1 --quiet " ++ repoUrl ++ " ./"
    system "git checkout HEAD --quiet"

main :: IO ()
main =
    inTemporaryDirectory "boilerplate" $ do
      cloneRepo "git@github.com:fujimura/wai-hspec-example.git"
      system "git ls-files"
      return ()