From 9c008f11166cbfa595812edeb85b98b722031c94 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Tue, 26 Apr 2016 15:44:11 -0400
Subject: [PATCH] Add a (failing) test that numberedRows produces the correct
 counts.

---
 test/AlignmentSpec.hs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/AlignmentSpec.hs b/test/AlignmentSpec.hs
index 06bd7e00b..2b3f6b1ee 100644
--- a/test/AlignmentSpec.hs
+++ b/test/AlignmentSpec.hs
@@ -1,6 +1,7 @@
 module AlignmentSpec where
 
 import Alignment
+import ArbitraryTerm ()
 import Control.Comonad.Cofree
 import Control.Monad.Free
 import Data.Align
@@ -22,6 +23,7 @@ import qualified Source
 import SplitDiff
 import Syntax
 import Test.Hspec
+import Test.Hspec.QuickCheck
 
 spec :: Spec
 spec = parallel $ do
@@ -100,6 +102,10 @@ spec = parallel $ do
                       (info 4 5 `branch` [ info 4 5 `leaf` "c" ]))
         ]
 
+  describe "numberedRows" $
+    prop "counts only non-empty values" $
+      \ xs -> counts (numberedRows (xs :: [Join These Char])) `shouldBe` length . catMaybes <$> Join (unalign (runJoin <$> xs))
+
 counts :: [Join These (Int, a)] -> Both Int
 counts numbered = fromMaybe 0 . getLast . mconcat . fmap Last <$> Join (unalign (runJoin . fmap Prelude.fst <$> numbered))