Support for records formatting (#256)

* Initial test describing simplest scenario for Data step

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* [sanity-check] Delete data defs

* Extract changeDecl

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* First green test :-)

* Cover case where there are more then one field in data type declaration

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Add case03 where a type variable is present

* Add case04 - multiple declarations

* Make case04 pass

* Extend tests with case05

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Add pending case06

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Fix case 06

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Add case07

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Add second phantom case

* Add records to config

* Make indent size configurable for records

Co-authored-by: Paweł Szulc <paul.szulc@gmail.com>

* Fix warnings in Data.hs

* Process derivings during record formatting

Co-authored-by: Paweł Szulc <paul.szulc@gmail.com>

* Do not format when context is present

Co-authored-by: Paweł Szulc <paul.szulc@gmail.com>

* Add case 11 - deriving with DerivingStrategies

* Bugfix: do not remove empty data declarations

Co-authored-by: Paweł Szulc <paul.szulc@gmail.com>

* Update README example with ability to format records

* Add case12 (Point)

* Fix case 12

* Factor out processName

* Apply hlint suggestions

* Extract constructors helper function

* Make 'indent' global

* Remove unused Stylish.records method

* Fix Config formatting in Config.hs

* Extract processConstructor function

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Refactor datas function

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Include comments with AST. Two tests are still failing...

* Fix cases 15 and 16

* Do not format records when comments within

Co-authored-by: Łukasz Gołębiewski <lukasz.golebiewski@gmail.com>

* Clean-up Data.hs

* Refactor Data.hs

Co-authored-by: Pawel Szulc <paul.szulc@gmail.com>

3 files changed, 372 insertions, 0 deletions

diff --git a/tests/Language/Haskell/Stylish/Config/Tests.hs b/tests/Language/Haskell/Stylish/Config/Tests.hs
index ebaef54..f8869ce 100644
--- a/tests/Language/Haskell/Stylish/Config/Tests.hs
+++ b/tests/Language/Haskell/Stylish/Config/Tests.hs
@@ -165,6 +165,8 @@ dotStylish = unlines $
   , "      align: false"
   , "      remove_redundant: true"
   , "  - trailing_whitespace: {}"
+  , "  - records: {}"
+  , "indent: 2"
   , "columns: 110"
   , "language_extensions:"
   , "  - TemplateHaskell"
diff --git a/tests/Language/Haskell/Stylish/Step/Data/Tests.hs b/tests/Language/Haskell/Stylish/Step/Data/Tests.hs
new file mode 100644
index 0000000..b152819
--- /dev/null
+++ b/tests/Language/Haskell/Stylish/Step/Data/Tests.hs
@@ -0,0 +1,368 @@
+module Language.Haskell.Stylish.Step.Data.Tests
+    ( tests
+    ) where
+
+import           Language.Haskell.Stylish.Step.Data
+import           Language.Haskell.Stylish.Tests.Util (testStep)
+import           Test.Framework                      (Test, testGroup)
+import           Test.Framework.Providers.HUnit      (testCase)
+import           Test.HUnit                          (Assertion, (@=?))
+
+tests :: Test
+tests = testGroup "Language.Haskell.Stylish.Step.Data.Tests"
+    [ testCase "case 00" case00
+    , testCase "case 01" case01
+    , testCase "case 02" case02
+    , testCase "case 03" case03
+    , testCase "case 04" case04
+    , testCase "case 05" case05
+    , testCase "case 06" case06
+    , testCase "case 07" case07
+    , testCase "case 08" case08
+    , testCase "case 09" case09
+    , testCase "case 10" case10
+    , testCase "case 11" case11
+    , testCase "case 12" case12
+    , testCase "case 13" case13
+    , testCase "case 14" case14
+    , testCase "case 15" case15
+    , testCase "case 16" case16
+    , testCase "case 17" case17
+    , testCase "case 18" case18
+    ]
+
+case00 :: Assertion
+case00 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo"
+      ]
+
+    expected = input
+
+case01 :: Assertion
+case01 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo { a :: Int }"
+      ]
+
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo = Foo"
+       , "  { a :: Int"
+       , "  }"
+       ]
+
+case02 :: Assertion
+case02 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo { a :: Int, a2 :: String }"
+      ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo = Foo"
+       , "  { a :: Int"
+       , "  , a2 :: String"
+       , "  }"
+       ]
+
+case03 :: Assertion
+case03 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo a = Foo { a :: a, a2 :: String }"
+      ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a"
+       , "  , a2 :: String"
+       , "  }"
+       ]
+
+case04 :: Assertion
+case04 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo a = Foo { a :: a, a2 :: String } | Bar { b :: a }"
+      ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a"
+       , "  , a2 :: String"
+       , "  }"
+       , "  | Bar"
+       , "  { b :: a"
+       , "  }"
+       ]
+
+case05 :: Assertion
+case05 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo = Foo {"
+       , "  a :: Int"
+       , "  , a2 :: String"
+       , "  }"
+       ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo = Foo"
+       , "  { a :: Int"
+       , "  , a2 :: String"
+       , "  }"
+       ]
+
+case06 :: Assertion
+case06 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo Int String"
+      ]
+    expected = input
+
+case07 :: Assertion
+case07 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Phantom a = Phantom"
+      ]
+    expected = input
+
+case08 :: Assertion
+case08 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Phantom a ="
+      , "  Phantom"
+      ]
+    expected = unlines
+      [ "module Herp where"
+      , ""
+      , "data Phantom a = Phantom"
+      ]
+
+case09 :: Assertion
+case09 = expected @=? testStep (step 4) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo a b = Foo { a :: a, a2 :: String } | Bar { b :: a, c:: b }"
+      ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a b = Foo"
+       , "    { a :: a"
+       , "    , a2 :: String"
+       , "    }"
+       , "    | Bar"
+       , "    { b :: a"
+       , "    , c :: b"
+       , "    }"
+       ]
+
+case10 :: Assertion
+case10 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo { a :: Int } deriving (Eq, Generic) deriving (Show)"
+      ]
+
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo = Foo"
+       , "  { a :: Int"
+       , "  }"
+       , "  deriving (Eq, Generic)"
+       , "  deriving (Show)"
+       ]
+
+case11 :: Assertion
+case11 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "{-# LANGUAGE DerivingStrategies #-}"
+      , "module Herp where"
+      , ""
+      , "data Foo = Foo { a :: Int } deriving stock (Show)"
+      ]
+
+    expected = unlines
+       [ "{-# LANGUAGE DerivingStrategies #-}"
+       , "module Herp where"
+       , ""
+       , "data Foo = Foo"
+       , "  { a :: Int"
+       , "  }"
+       , "  deriving stock (Show)"
+       ]
+
+case12 :: Assertion
+case12 = expected @=? testStep (step 4) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Point = Point { pointX, pointY :: Double , pointName :: String} deriving (Show)"
+      ]
+
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Point = Point"
+       , "    { pointX, pointY :: Double"
+       , "    , pointName :: String"
+       , "    }"
+       , "    deriving (Show)"
+       ]
+
+case13 :: Assertion
+case13 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "-- this is a comment"
+      , "data Foo = Foo { a :: Int }"
+      ]
+    expected = unlines
+      [ "module Herp where"
+      , ""
+      , "-- this is a comment"
+      , "data Foo = Foo"
+      , "  { a :: Int"
+      , "  }"
+      ]
+
+case14 :: Assertion
+case14 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "{- this is"
+      , "   a comment -}"
+      , "data Foo = Foo { a :: Int }"
+      ]
+    expected = unlines
+      [ "module Herp where"
+      , ""
+      , "{- this is"
+      , "   a comment -}"
+      , "data Foo = Foo"
+      , "  { a :: Int"
+      , "  }"
+      ]
+
+case15 :: Assertion
+case15 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo {"
+      , "   a :: Int -- ^ comment"
+      , "  }"
+      ]
+    expected = unlines
+      [ "module Herp where"
+      , ""
+      , "data Foo = Foo {"
+      , "   a :: Int -- ^ comment"
+      , "  }"
+      ]
+
+case16 :: Assertion
+case16 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a,"
+       , "-- ^ comment"
+       , "   a2 :: String"
+       , "  }"
+       ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a,"
+       , "-- ^ comment"
+       , "   a2 :: String"
+       , "  }"
+       ]
+
+case17 :: Assertion
+case17 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a, -- comment"
+       , "   a2 :: String"
+       , "  }"
+       ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a, -- comment"
+       , "   a2 :: String"
+       , "  }"
+       ]
+
+case18 :: Assertion
+case18 = expected @=? testStep (step 2) input
+  where
+    input = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a,"
+       , "-- comment "
+       , "   a2 :: String"
+       , "  }"
+       ]
+    expected = unlines
+       [ "module Herp where"
+       , ""
+       , "data Foo a = Foo"
+       , "  { a :: a,"
+       , "-- comment "
+       , "   a2 :: String"
+       , "  }"
+       ]
diff --git a/tests/TestSuite.hs b/tests/TestSuite.hs
index b5bec90..a6f51ea 100644
--- a/tests/TestSuite.hs
+++ b/tests/TestSuite.hs
@@ -11,6 +11,7 @@ import           Test.Framework                                         (default
 --------------------------------------------------------------------------------
 import qualified Language.Haskell.Stylish.Config.Tests
 import qualified Language.Haskell.Stylish.Parse.Tests
+import qualified Language.Haskell.Stylish.Step.Data.Tests
 import qualified Language.Haskell.Stylish.Step.Imports.Tests
 import qualified Language.Haskell.Stylish.Step.LanguagePragmas.Tests
 import qualified Language.Haskell.Stylish.Step.SimpleAlign.Tests
@@ -25,6 +26,7 @@ main :: IO ()
 main = defaultMain
     [ Language.Haskell.Stylish.Parse.Tests.tests
     , Language.Haskell.Stylish.Config.Tests.tests
+    , Language.Haskell.Stylish.Step.Data.Tests.tests
     , Language.Haskell.Stylish.Step.Imports.Tests.tests
     , Language.Haskell.Stylish.Step.LanguagePragmas.Tests.tests
     , Language.Haskell.Stylish.Step.SimpleAlign.Tests.tests