Fix warnings in tests

Author: Bodigrim

test/Codec/Archive/Tar/Index/StringTable/Tests.hs

@@ -49,7 +49,7 @@ prop_sorted strings = property $
   where
     _tbl :: StringTable Int
     _tbl@(StringTable strs offsets ids _ixs) = construct strings
-    isSorted xs = and (zipWith (<) xs (tail xs))
+    isSorted xs = and (zipWith (<) xs (drop 1 xs))
 
 prop_finalise_unfinalise :: [BS.ByteString] -> Property
 prop_finalise_unfinalise strs =

test/Codec/Archive/Tar/Index/Tests.hs

@@ -70,9 +70,10 @@ prop_lookup (ValidPaths paths) (NonEmptyFilePath p) =
     _                                              -> property False
   where
     index       = construct paths
-    completions = [ head (FilePath.splitDirectories completion)
+    completions = [ hd
                   | (path,_) <- paths
-                  , completion <- maybeToList $ stripPrefix (p ++ "/") path ]
+                  , completion <- maybeToList $ stripPrefix (p ++ "/") path
+                  , let hd : _ = FilePath.splitDirectories completion ]
 
 prop_toList :: ValidPaths -> Property
 prop_toList (ValidPaths paths) =