output ansi styles only to tty, fixes tests

1 files changed, 11 insertions, 3 deletions

diff --git a/app/Main.hs b/app/Main.hs
index 60c81e4..151115e 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
 {-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
 {-# LANGUAGE OverloadedRecordDot #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PartialTypeSignatures #-}
@@ -58,7 +59,7 @@ import Issue.Tag qualified as I
 import Options.Applicative ((<**>))
 import Options.Applicative qualified as O
 import Prettyprinter qualified as P
-import Prettyprinter.Render.Terminal as P
+import Prettyprinter.Render.Terminal qualified as P
 import System.Exit (ExitCode (ExitFailure), exitWith)
 import System.FilePath qualified as F
 import System.IO (hPutStrLn, stderr)
@@ -125,7 +126,7 @@ main = do
 
 showMatches :: [Issue] -> IO ()
 showMatches issues = do
-  P.putDoc . P.vsep $
+  putDoc . P.vsep $
     map
       ( \issue ->
           P.vsep
@@ -141,7 +142,7 @@ showMatches issues = do
 
 listMatches :: [Issue] -> IO ()
 listMatches issues =
-  P.putDoc . P.vsep $
+  putDoc . P.vsep $
     map
       ( \issue ->
           P.hsep
@@ -158,6 +159,13 @@ listMatches issues =
       )
       issues
 
+putDoc :: P.Doc P.AnsiStyle -> IO ()
+putDoc doc = do
+  isTty <- (== 1) <$> c_isatty 1
+  P.putDoc . (if isTty then id else P.unAnnotate) $ doc
+
+foreign import ccall "unistd.h isatty" c_isatty :: Int -> IO Int
+
 data UnknownFileExtension = UnknownFileExtension
   { extension :: String
   }