io-capture-0.3: tests/Tests.hs

import Test.Torch
import Control.Monad.Trans
import System.IO (hPutStrLn,stderr)
import System.IO.Capture (capture)

main = run $ do
  (out,err) <- liftIO $ capture (putStrLn "foo") []
  is out "foo\n" "stdout is captured"
  ok (null err)  "stderr is also captured"

  (out,err) <- liftIO $ capture (getLine >>= putStrLn >>
                                 getLine >>= hPutStrLn stderr)
                                "foo\nbar\n"
  is out "foo\n" "stdin can be given; stdout is still captured"
  is err "bar\n" "stdin can be given; stderr is still captured"

  (_,err) <- liftIO $ capture undefined []
  is err "*** Exception: Prelude.undefined\n" "error message in stderr is also captured"

  (out,err) <- liftIO $ capture (getContents >>= putStr) "foobarbaz\nquux\n"
  is out "foobarbaz\nquux\n" "lazy io also works; stdout captured"
  ok (null err)              "lazy io also works; stderr captured"

  (out,err) <- liftIO $ capture (getLine >>= putStrLn >>
                                 getLine >>= hPutStrLn stderr)
                                "foo\nbar\n"
  is out "foo\n" "after lazy-io, stdout is still captured"
  is err "bar\n" "after lazy-io, stderr is still captured"