From b124b461c0ed0e0c72c8bafadbb445d27979bf38 Mon Sep 17 00:00:00 2001
From: joshvera <vera@github.com>
Date: Tue, 1 Mar 2016 17:13:53 -0500
Subject: [PATCH] Empty diffs have empty hunks

---
 src/Renderer/Patch.hs   | 6 ++++--
 test/PatchOutputSpec.hs | 4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Renderer/Patch.hs b/src/Renderer/Patch.hs
index 471d707e8..bbb1a92c9 100644
--- a/src/Renderer/Patch.hs
+++ b/src/Renderer/Patch.hs
@@ -1,6 +1,7 @@
 module Renderer.Patch (
   patch,
-  hunks
+  hunks,
+  Hunk(..)
 ) where
 
 import Alignment
@@ -88,13 +89,14 @@ header blobs hunk = filepathHeader ++ blobOidHeader ++ maybeOffsetHeader
 
 -- | Render a diff as a series of hunks.
 hunks :: Renderer a [Hunk (SplitDiff a Info)]
+hunks diff blobs | (Both (True, True) ==) $ Source.null . source <$> blobs = [Hunk { offset = Both (0, 0), changes = [], trailingContext = [] }]
 hunks diff blobs = hunksInRows (Both (1, 1)) . Prelude.fst $ splitDiffByLines diff (pure 0) (source <$> blobs)
 
 -- | Given beginning line numbers, turn rows in a split diff into hunks in a
 -- | patch.
 hunksInRows :: Both (Sum Int) -> [Row (SplitDiff a Info)] -> [Hunk (SplitDiff a Info)]
 hunksInRows start rows = case nextHunk start rows of
-  Nothing -> [Hunk { offset = Both (0, 0), changes = [], trailingContext = [] }]
+  Nothing -> []
   Just (hunk, rest) -> hunk : hunksInRows (offset hunk <> hunkLength hunk) rest
 
 -- | Given beginning line numbers, return the next hunk and the remaining rows
diff --git a/test/PatchOutputSpec.hs b/test/PatchOutputSpec.hs
index c368b4431..04d2bf38e 100644
--- a/test/PatchOutputSpec.hs
+++ b/test/PatchOutputSpec.hs
@@ -12,5 +12,5 @@ import Test.Hspec
 spec :: Spec
 spec = parallel $
   describe "hunks" $
-    it "empty diffs have no hunks" $
-      hunks (Free . Annotated (pure (Info (Range 0 0) mempty)) $ Leaf "") (Both (SourceBlob (fromList "") "abcde" "path2.txt", SourceBlob (fromList "") "xyz" "path2.txt")) `shouldBe` []
+    it "empty diffs have empty hunks" $
+        hunks (Free . Annotated (pure (Info (Range 0 0) mempty)) $ Leaf "") (Both (SourceBlob (fromList "") "abcde" "path2.txt", SourceBlob (fromList "") "xyz" "path2.txt")) `shouldBe` [Hunk {offset = Both (0, 0), changes = [], trailingContext = []}]