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

test/CaseSplitSpec.hs

@@ -0,0 +1,25 @@
+{-# LANGUAGE CPP #-}
+module CaseSplitSpec where
+
+import Control.Applicative ((<$>))
+import Data.List (isPrefixOf)
+import Language.Haskell.GhcMod
+#if __GLASGOW_HASKELL__ < 706
+import System.Environment.Executable (getExecutablePath)
+#else
+import System.Environment (getExecutablePath)
+#endif
+import System.Exit
+import System.FilePath
+import System.Process
+import Test.Hspec
+import TestUtils
+import Dir
+
+spec :: Spec
+spec = do
+    describe "case split" $ do
+        it "does not blow up on HsWithBndrs panic" $ do
+            withDirectory_ "test/data/case-split" $ do
+                res <- runD $ splits "Vect.hs" 24 10
+                res `shouldBe` "9 5 11 40 \"Int -> a -> a -> a\"\n7 1 11 40 \"Int -> Integer\"\n"