New import list option

new line-multiline: Import list will start on new line when it's
short enough to fit to single line. Otherwise it'll be multiline.

4 files changed, 46 insertions, 3 deletions

diff --git a/data/stylish-haskell.yaml b/data/stylish-haskell.yaml
index 28b994e..86baae3 100644
--- a/data/stylish-haskell.yaml
+++ b/data/stylish-haskell.yaml
@@ -63,6 +63,9 @@ steps:
       #
       # - new line: Import list will start on new line.
       #
+      # - new line-multiline: Import list will start on new line when it's
+      #   short enough to fit to single line. Otherwise it'll be multiline.
+      #
       # - multiline: One line per import list entry.
       #   Type with contructor list acts like single import.
       #
diff --git a/src/Language/Haskell/Stylish/Config.hs b/src/Language/Haskell/Stylish/Config.hs
index b8ae588..271a461 100644
--- a/src/Language/Haskell/Stylish/Config.hs
+++ b/src/Language/Haskell/Stylish/Config.hs
@@ -187,9 +187,10 @@ parseImports config o = Imports.step
         ]
 
     longListAligns =
-        [ ("inline",    Imports.Inline)
-        , ("new line",  Imports.InlineWithBreak)
-        , ("multiline", Imports.Multiline)
+        [ ("inline",             Imports.Inline)
+        , ("new line",           Imports.InlineWithBreak)
+        , ("new line-multiline", Imports.InlineToMultiline)
+        , ("multiline",          Imports.Multiline)
         ]
 
 
diff --git a/src/Language/Haskell/Stylish/Step/Imports.hs b/src/Language/Haskell/Stylish/Step/Imports.hs
index db4e63e..2cd8e6c 100644
--- a/src/Language/Haskell/Stylish/Step/Imports.hs
+++ b/src/Language/Haskell/Stylish/Step/Imports.hs
@@ -52,6 +52,7 @@ data ListAlign
 data LongListAlign
     = Inline
     | InlineWithBreak
+    | InlineToMultiline
     | Multiline
     deriving (Eq, Show)
 
@@ -141,6 +142,7 @@ prettyImport columns Align{..} padQualified padName longest imp =
     case longListAlign of
         Inline -> inlineWrap
         InlineWithBreak -> longListWrapper inlineWrap inlineWithBreakWrap
+        InlineToMultiline -> longListWrapper inlineWrap inlineToMultilineWrap
         Multiline -> longListWrapper inlineWrap multilineWrap
   where
     longListWrapper shortWrap longWrap
@@ -169,6 +171,12 @@ prettyImport columns Align{..} padQualified padName longest imp =
         . withHead ("(" ++)
         . withLast (++ ")"))
 
+    inlineToMultilineWrap
+        | length inlineWithBreakWrap > 2
+        || any ((> columns) . length) (tail inlineWithBreakWrap)
+            = multilineWrap
+        | otherwise = inlineWithBreakWrap
+
     -- 'wrapRest 0' ensures that every item of spec list is on new line.
     multilineWrap = paddedNoSpecBase : wrapRest 0 listPadding
         ( mapSpecs
diff --git a/tests/Language/Haskell/Stylish/Step/Imports/Tests.hs b/tests/Language/Haskell/Stylish/Step/Imports/Tests.hs
index 36e54d9..4ed0bd6 100644
--- a/tests/Language/Haskell/Stylish/Step/Imports/Tests.hs
+++ b/tests/Language/Haskell/Stylish/Step/Imports/Tests.hs
@@ -44,6 +44,7 @@ tests = testGroup "Language.Haskell.Stylish.Step.Imports.Tests"
     , testCase "case 15" case15
     , testCase "case 16" case16
     , testCase "case 17" case17
+    , testCase "case 18" case18
     ]
 
 
@@ -346,6 +347,7 @@ case14 = expected
         [ "import qualified Data.List as List (concat, map, null, reverse, tail, (++))"
         ]
 
+
 --------------------------------------------------------------------------------
 case15 :: Assertion
 case15 = expected
@@ -395,6 +397,7 @@ case16 = expected
         , "import Data.Foo (Foo (Foo,Bar), Goo(Goo))"
         ]
 
+
 --------------------------------------------------------------------------------
 case17 :: Assertion
 case17 = expected
@@ -411,3 +414,31 @@ case17 = expected
         , ""
         , "import Data.Identity (Identity (runIdentity,Identity))"
         ]
+
+
+--------------------------------------------------------------------------------
+case18 :: Assertion
+case18 = expected @=? testStep
+    (step 40 $ Align None AfterAlias InlineToMultiline 4 True) input'
+  where
+    expected = unlines
+           ----------------------------------------
+        [ "import Data.Foo as Foo (Bar, Baz, Foo)"
+        , ""
+        , "import Data.Identity"
+        , "    (Identity (Identity, runIdentity))"
+        , ""
+        , "import Data.Acid as Acid"
+        , "    ( closeAcidState"
+        , "    , createCheckpoint"
+        , "    , openLocalStateFrom"
+        , "    )"
+        ]
+
+    input' = unlines
+        [ "import Data.Foo as Foo (Bar, Baz, Foo)"
+        , ""
+        , "import Data.Identity (Identity (Identity, runIdentity))"
+        , ""
+        , "import Data.Acid as Acid (closeAcidState, createCheckpoint, openLocalStateFrom)"
+        ]