1 files changed, 51 insertions, 0 deletions
diff --git a/tests/Properties/Stack.hs b/tests/Properties/Stack.hs
new file mode 100644
index 0000000..586df1d
--- /dev/null
+++ b/tests/Properties/Stack.hs
@@ -0,0 +1,51 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Properties.Stack where
+
+import Test.QuickCheck
+import Instances
+
+import XMonad.StackSet hiding (filter)
+import qualified XMonad.StackSet as S (filter)
+
+import Data.Maybe
+
+
+-- The list returned by index should be the same length as the actual
+-- windows kept in the zipper
+prop_index_length (x :: T) =
+    case stack . workspace . current $ x of
+        Nothing   -> length (index x) == 0
+        Just it -> length (index x) == length (focus it : up it ++ down it)
+
+
+-- For all windows in the stackSet, findTag should identify the
+-- correct workspace
+prop_findIndex (x :: T) =
+    and [ tag w == fromJust (findTag i x)
+        | w <- workspace (current x) : map workspace (visible x)  ++ hidden x
+        , t <- maybeToList (stack w)
+        , i <- focus t : up t ++ down t
+        ]
+
+prop_allWindowsMember (NonEmptyWindowsStackSet x) = do
+      -- Reimplementation of arbitraryWindow, but to make sure that
+      -- implementation doesn't change in the future, and stop using allWindows,
+      -- which is a key component in this test (together with member).
+  let ws = allWindows x
+  -- We know that there are at least 1 window in a NonEmptyWindowsStackSet.
+  idx <- choose(0, (length ws) - 1)
+  return $ member (ws!!idx) x
+
+
+-- preserve order
+prop_filter_order (x :: T) =
+    case stack $ workspace $ current x of
+        Nothing -> True
+        Just s@(Stack i _ _) -> integrate' (S.filter (/= i) s) == filter (/= i) (integrate' (Just s))
+
+-- differentiate should return Nothing if the list is empty or Just stack, with
+-- the first element of the list is current, and the rest of the list is down.
+prop_differentiate xs =
+        if null xs then differentiate xs == Nothing
+                   else (differentiate xs) == Just (Stack (head xs) [] (tail xs))
+    where _ = xs :: [Int]