Fix 443-specify-path integration test on Windows

test/integration/tests/443-specify-path/Main.hs

@@ -1,27 +1,30 @@
 import StackTest
 import System.Directory
 import System.FilePath
+import System.Info (os)
 
 main :: IO ()
 main = do
+  let ext = if os == "mingw32" then ".exe" else ""
+
   -- install in relative path
   createDirectory "bin"
   stack ["--local-bin-path", "./bin", "install" , "happy"]
-  doesExist "./bin/happy"
+  doesExist ("./bin/happy" ++ ext)
 
   -- Default install
   -- This seems to fail due to direcory being cleaned up,
   -- a manual test of the default stack install is required
   -- defaultDir <- getAppUserDataDirectory "local"
   -- stack ["install", "happy"]
-  -- doesExist (defaultDir ++ "/bin/happy")
+  -- doesExist (defaultDir ++ "/bin/happy" ++ ext)
 
   -- install in current dir
   stack ["--local-bin-path", ".", "install", "happy" ]
-  doesExist "happy"
+  doesExist ("happy" ++ ext)
 
   -- install in absolute path
   tmpDirectory <- fmap (</> "absolute-bin") getCurrentDirectory
   createDirectory tmpDirectory
   stack ["--local-bin-path", tmpDirectory, "install", "happy" ]
-  doesExist (tmpDirectory </> "happy")
+  doesExist (tmpDirectory </> ("happy" ++ ext))