add splitAt

1 files changed, 17 insertions, 0 deletions

diff --git a/test/Spec.hs b/test/Spec.hs
index 6cf4d2f..24a17e2 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE MultiWayIf #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 import Blessings.Internal as B
@@ -43,6 +44,22 @@ main =
         property $ \(x :: Blessings String) ->
           normalize (B.take 1 x <> B.drop 1 x) == normalize x
 
+      it "uncurry (<>) (splitAt i x) == x" $
+        property $ \(i :: Int, x :: Blessings String) ->
+          unsafeTimeout 100000 $
+            normalize (uncurry (<>) (B.splitAt i x)) == normalize x
+
+      it "splitAt produces pairs with elements of proper length" $
+        property $ \(i :: Int, x :: Blessings String) ->
+          unsafeTimeout 100000 $
+            let
+              (l, r) = B.splitAt i x
+              n = B.length x
+            in
+            if | i <= 0    -> B.length l == 0 && B.length r == n
+               | i <= n    -> B.length l == i && B.length r == n - i
+               | otherwise -> B.length l == n && B.length r == 0
+
       let infx = mconcat (repeat (Plain "x" :: Blessings String))
 
       it "can take from infinite structure" $