Adding test case for https://github.com/kazu-yamamoto/ghc-mod/issues/336

test/data/case-split/Vect.hs

@@ -0,0 +1,24 @@
+{-# LANGUAGE DataKinds, TypeFamilies, TypeOperators, GADTs, KindSignatures #-}
+
+module Vect where
+
+data Nat = Z | S Nat
+
+type family   (n :: Nat) :+ (m :: Nat) :: Nat
+type instance Z :+ m = m
+type instance S n :+ m = S (n :+ m)
+
+data Vect :: Nat -> * -> * where
+  VNil :: Vect Z a
+  (:::) :: a -> Vect n a -> Vect (S n) a
+
+vAppend :: Vect n a -> Vect m a -> Vect (n :+ m) a
+vAppend x y = _vAppend_body
+
+lAppend :: [a] -> [a] -> [a]
+lAppend x y = _lAppend_body
+
+data MyList a = Nil | Cons a (MyList a)
+
+mlAppend :: MyList a -> MyList a -> MyList a
+mlAppend x y = _mlAppend_body