Fix #622 Handle multi-line value for field description

Author: mpilgrem

src/Hpack/Render.hs

@@ -145,17 +145,25 @@ sortStanzaFields sectionsFieldOrder = go
       Stanza name fields : xs | Just fieldOrder <- lookup name sectionsFieldOrder -> Stanza name (sortFieldsBy fieldOrder fields) : go xs
       x : xs -> x : go xs
 
+descriptionFieldSize :: Int
+descriptionFieldSize = length ("description: " :: String)
+
 formatDescription :: CabalVersion -> Alignment -> String -> String
-formatDescription cabalVersion (Alignment alignment) description = case formatDescription' cabalVersion description of
+formatDescription cabalVersion (Alignment alignment) description = case map emptyLineToDot $ lines description of
   x : xs -> intercalate "\n" (x : indent xs)
   [] -> ""
   where
     n :: Int
-    n = max alignment (length ("description: " :: String))
+    n = max alignment descriptionFieldSize
 
     indentation :: String
     indentation = replicate n ' '
 
+    emptyLineToDot :: String -> String
+    emptyLineToDot xs
+      | isEmptyLine xs && cabalVersion < makeCabalVersion [3] = "."
+      | otherwise = xs
+
     indent :: [String] -> [String]
     indent = map indentLine
 
@@ -164,16 +172,8 @@ formatDescription cabalVersion (Alignment alignment) description = case formatDe
       | isEmptyLine xs = ""
       | otherwise = indentation ++ xs
 
-isEmptyLine :: String -> Bool
-isEmptyLine = all isSpace
-
-formatDescription' :: CabalVersion -> String -> [String]
-formatDescription' cabalVersion = map emptyLineToDot . lines
-  where
-    emptyLineToDot :: String -> String
-    emptyLineToDot xs
-      | isEmptyLine xs && cabalVersion < makeCabalVersion [3] = "."
-      | otherwise = xs
+    isEmptyLine :: String -> Bool
+    isEmptyLine = all isSpace
 
 renderSourceRepository :: SourceRepository -> Element
 renderSourceRepository SourceRepository{..} = Stanza "source-repository head" [
@@ -188,8 +188,11 @@ renderFlag cabalVersion Flag {..} = Stanza ("flag " ++ flagName) $ description +
   , Field "default" (Literal $ show flagDefault)
   ]
   where
-    description = maybe [] (return . Field "description" . LineSeparatedList) formattedFlagDescription
-    formattedFlagDescription = formatDescription' cabalVersion <$> flagDescription
+    description = maybe [] (return . Field "description" . Literal) formattedFlagDescription
+    -- We have to 'hard code' that the flag stanza's description field is
+    -- indented by two spaces:
+    alignment = Alignment (descriptionFieldSize + 2)
+    formattedFlagDescription = formatDescription cabalVersion alignment <$> flagDescription
 
 renderInternalLibraries :: Map String (Section Library) -> RenderM [Element]
 renderInternalLibraries = traverse renderInternalLibrary . Map.toList

test/Hpack/RenderSpec.hs

@@ -276,8 +276,7 @@ spec = do
       let flag = (Flag "foo" (Just "some flag") True False)
       render defaultRenderSettings 0 (renderFlag cabalVersion flag) `shouldBe` [
           "flag foo"
-        , "  description:"
-        , "      some flag"
+        , "  description: some flag"
         , "  manual: True"
         , "  default: False"
         ]