Add new thenPlacement option

bin/src/Bin/FormatOptions.purs

@@ -13,14 +13,15 @@ import Data.Argonaut.Encode (assoc, encodeJson, extend)
 import Data.Either (Either)
 import Data.Maybe (Maybe(..), fromMaybe, maybe)
 import Data.Traversable (traverse)
-import Tidy (ImportSortOption(..), ImportWrapOption(..), TypeArrowOption(..), UnicodeOption(..))
+import Tidy (ImportSortOption(..), ImportWrapOption(..), ThenPlacementOption(..), TypeArrowOption(..), UnicodeOption(..))
 
 type FormatOptions =
   { importSort :: ImportSortOption
   , importWrap :: ImportWrapOption
   , indent :: Int
   , operatorsFile :: Maybe String
   , ribbon :: Number
+  , thenPlacement :: ThenPlacementOption
   , typeArrowPlacement :: TypeArrowOption
   , unicode :: UnicodeOption
   , width :: Maybe Int
@@ -33,6 +34,7 @@ defaults =
   , indent: 2
   , operatorsFile: Nothing
   , ribbon: 1.0
+  , thenPlacement: ThenSameLine
   , typeArrowPlacement: TypeArrowFirst
   , unicode: UnicodeSource
   , width: Nothing
@@ -76,6 +78,16 @@ formatOptions =
           "The ratio of printable width to maximum width.\nFrom 0 to 1. Defaults to 1."
           # Arg.number
           # Arg.default defaults.ribbon
+    , thenPlacement:
+        Arg.choose "then placement"
+          [ Arg.flag [ "--then-same-line", "-tsl" ]
+              "Then keyword is placed on the same line as the if condition.\nDefault."
+              $> ThenSameLine
+          , Arg.flag [ "--then-new-line", "-tnl" ]
+              "Then keyword is placed on a new line."
+              $> ThenNewLine
+          ]
+          # Arg.default defaults.thenPlacement
     , typeArrowPlacement:
         Arg.choose "type arrow placement"
           [ Arg.flag [ "--arrow-first", "-af" ]
@@ -117,6 +129,7 @@ fromJson json = do
   indent <- obj .:? "indent"
   operatorsFile <- obj .:? "operatorsFile"
   ribbon <- obj .:? "ribbon"
+  thenPlacement <- traverse thenPlacementFromString =<< obj .:? "thenPlacement"
   typeArrowPlacement <- traverse typeArrowPlacementFromString =<< obj .:? "typeArrowPlacement"
   unicode <- traverse unicodeFromString =<< obj .:? "unicode"
   width <- obj .:? "width"
@@ -126,6 +139,7 @@ fromJson json = do
     , indent: fromMaybe defaults.indent indent
     , operatorsFile: operatorsFile <|> defaults.operatorsFile
     , ribbon: fromMaybe defaults.ribbon ribbon
+    , thenPlacement: fromMaybe defaults.thenPlacement thenPlacement
     , typeArrowPlacement: fromMaybe defaults.typeArrowPlacement typeArrowPlacement
     , unicode: fromMaybe defaults.unicode unicode
     , width: width <|> defaults.width
@@ -139,10 +153,22 @@ toJson options =
     # extend (assoc "indent" options.indent)
     # extend (assoc "operatorsFile" (maybe jsonNull encodeJson options.operatorsFile))
     # extend (assoc "ribbon" options.ribbon)
+    # extend (assoc "thenPlacement" (thenPlacementToString options.thenPlacement))
     # extend (assoc "typeArrowPlacement" (typeArrowPlacementToString options.typeArrowPlacement))
     # extend (assoc "unicode" (unicodeToString options.unicode))
     # extend (assoc "width" (maybe jsonNull encodeJson options.width))
 
+thenPlacementFromString :: String -> Either JsonDecodeError ThenPlacementOption
+thenPlacementFromString = case _ of
+  "same-line" -> pure ThenSameLine
+  "new-line" -> pure ThenNewLine
+  other -> throwError $ UnexpectedValue (Json.fromString other)
+
+thenPlacementToString :: ThenPlacementOption -> String
+thenPlacementToString = case _ of
+  ThenSameLine -> "same-line"
+  ThenNewLine -> "new-line"
+
 typeArrowPlacementFromString :: String -> Either JsonDecodeError TypeArrowOption
 typeArrowPlacementFromString = case _ of
   "first" -> pure TypeArrowFirst

bin/src/Bin/Worker.purs

@@ -37,6 +37,7 @@ type WorkerConfig =
   , indent :: Int
   , operatorsFile :: String
   , ribbon :: Number
+  , thenPlacement :: String
   , typeArrowPlacement :: String
   , unicode :: String
   , width :: Int
@@ -49,6 +50,7 @@ toWorkerConfig options =
   , indent: options.indent
   , operatorsFile: fromMaybe ".tidyoperators.default" options.operatorsFile
   , ribbon: options.ribbon
+  , thenPlacement: FormatOptions.thenPlacementToString options.thenPlacement
   , typeArrowPlacement: FormatOptions.typeArrowPlacementToString options.typeArrowPlacement
   , unicode: FormatOptions.unicodeToString options.unicode
   , width: fromMaybe top options.width
@@ -88,6 +90,7 @@ formatCommand args operators contents = do
           { importSort = args.importSort
           , importWrap = args.importWrap
           , operators = remapOperators operators ok
+          , thenPlacement = args.thenPlacement
           , typeArrowPlacement = args.typeArrowPlacement
           , unicode = args.unicode
           }
@@ -115,6 +118,9 @@ formatInPlaceCommand shouldCheck operators { filePath, config } = do
       , indent: config.indent
       , operatorsFile: Nothing
       , ribbon: config.ribbon
+      , thenPlacement:
+          fromRight' (\_ -> unsafeCrashWith "Unknown thenPlacement value") do
+            FormatOptions.thenPlacementFromString config.thenPlacement
       , typeArrowPlacement:
           fromRight' (\_ -> unsafeCrashWith "Unknown typeArrowPlacement value") do
             FormatOptions.typeArrowPlacementFromString config.typeArrowPlacement

src/Tidy.purs

@@ -2,6 +2,7 @@ module Tidy
   ( FormatOptions
   , defaultFormatOptions
   , TypeArrowOption(..)
+  , ThenPlacementOption(..)
   , ImportSortOption(..)
   , ImportWrapOption(..)
   , Format
@@ -50,6 +51,12 @@ data TypeArrowOption
 
 derive instance eqTypeArrowOption :: Eq TypeArrowOption
 
+data ThenPlacementOption
+  = ThenSameLine
+  | ThenNewLine
+
+derive instance eqThenPlacementOption :: Eq ThenPlacementOption
+
 data ImportWrapOption
   = ImportWrapSource
   | ImportWrapAuto
@@ -66,6 +73,7 @@ type FormatOptions e a =
   { formatError :: e -> FormatDoc a
   , unicode :: UnicodeOption
   , typeArrowPlacement :: TypeArrowOption
+  , thenPlacement :: ThenPlacementOption
   , operators :: PrecedenceMap
   , importSort :: ImportSortOption
   , importWrap :: ImportWrapOption
@@ -76,6 +84,7 @@ defaultFormatOptions =
   { formatError
   , unicode: UnicodeSource
   , typeArrowPlacement: TypeArrowFirst
+  , thenPlacement: ThenSameLine
   , operators: Map.empty
   , importSort: ImportSortSource
   , importWrap: ImportWrapSource
@@ -991,19 +1000,37 @@ toElseIfChain ifte = go (pure (IfThen ifte.keyword ifte.cond ifte.then ifte.true
 formatElseIfChain :: forall e a. Format (NonEmptyArray (ElseIfChain e)) e a
 formatElseIfChain conf = flexGroup <<< joinWithMap spaceBreak case _ of
   IfThen kw1 cond kw2 expr ->
-    formatToken conf kw1
-      `flexSpaceBreak`
-        indent (anchor (flexGroup (formatExpr conf cond)))
-      `space`
-        Hang.toFormatDoc (anchor (formatToken conf kw2) `hang` formatHangingExpr conf expr)
+    case conf.thenPlacement of
+      ThenSameLine ->
+        formatToken conf kw1
+          `flexSpaceBreak`
+            indent (anchor (flexGroup (formatExpr conf cond)))
+          `space`
+            Hang.toFormatDoc (anchor (formatToken conf kw2) `hang` formatHangingExpr conf expr)
+      ThenNewLine ->
+        formatToken conf kw1
+          `flexSpaceBreak`
+            indent (anchor (flexGroup (formatExpr conf cond)))
+          `break`
+            Hang.toFormatDoc (anchor (formatToken conf kw2) `hang` formatHangingExpr conf expr)
   ElseIfThen kw1 kw2 cond kw3 expr ->
-    formatToken conf kw1
-      `space`
-        indent (anchor (formatToken conf kw2))
-      `flexSpaceBreak`
-        indent (anchor (flexGroup (formatExpr conf cond)))
-      `space`
-        Hang.toFormatDoc (anchor (formatToken conf kw3) `hang` formatHangingExpr conf expr)
+    case conf.thenPlacement of
+      ThenSameLine ->
+        formatToken conf kw1
+          `space`
+            indent (anchor (formatToken conf kw2))
+          `flexSpaceBreak`
+            indent (anchor (flexGroup (formatExpr conf cond)))
+          `space`
+            Hang.toFormatDoc (anchor (formatToken conf kw3) `hang` formatHangingExpr conf expr)
+      ThenNewLine ->
+        formatToken conf kw1
+          `space`
+            indent (anchor (formatToken conf kw2))
+          `flexSpaceBreak`
+            indent (anchor (flexGroup (formatExpr conf cond)))
+          `break`
+            Hang.toFormatDoc (anchor (formatToken conf kw3) `hang` formatHangingExpr conf expr)
   Else kw1 expr ->
     Hang.toFormatDoc (formatToken conf kw1 `hang` formatHangingExpr conf expr)
 

test/FormatDirective.purs

@@ -111,6 +111,7 @@ parseDirectivesFromModule (Module { header: ModuleHeader header, body }) =
         { formatError: default.formatError
         , operators: default.operators
         , unicode: opts.unicode
+        , thenPlacement: opts.thenPlacement
         , typeArrowPlacement: opts.typeArrowPlacement
         , importSort: opts.importSort
         , importWrap: opts.importWrap

test/snapshots/ThenPlacementComparison.input

@@ -0,0 +1,16 @@
+-- @format --then-same-line --width 40
+module ThenPlacementComparison where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if someVeryLongConditionExpressionThatWillDefinitelyWrap
+    then shortResult
+    else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition
+    then if secondLongCondition
+      then result1
+      else result2
+    else alternativeResult

test/snapshots/ThenPlacementComparison.output

@@ -0,0 +1,29 @@
+module ThenPlacementComparison where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if someVeryLongConditionExpressionThatWillDefinitelyWrap then shortResult
+  else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition then
+    if secondLongCondition then result1
+    else result2
+  else alternativeResult
+-- @format --then-same-line --width 40
+module ThenPlacementComparison where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if
+    someVeryLongConditionExpressionThatWillDefinitelyWrap then
+    shortResult
+  else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition then
+    if secondLongCondition then result1
+    else result2
+  else alternativeResult

test/snapshots/ThenPlacementDifference.input

@@ -0,0 +1,16 @@
+-- @format --then-new-line --width 40
+module ThenPlacementDifference where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if someVeryLongConditionExpressionThatWillDefinitelyWrap
+    then shortResult
+    else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition
+    then if secondLongCondition
+      then result1
+      else result2
+    else alternativeResult

test/snapshots/ThenPlacementDifference.output

@@ -0,0 +1,31 @@
+module ThenPlacementDifference where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if someVeryLongConditionExpressionThatWillDefinitelyWrap then shortResult
+  else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition then
+    if secondLongCondition then result1
+    else result2
+  else alternativeResult
+-- @format --then-new-line --width 40
+module ThenPlacementDifference where
+
+-- This should trigger the difference with narrow width
+test1 =
+  if
+    someVeryLongConditionExpressionThatWillDefinitelyWrap
+  then shortResult
+  else alternativeValue
+
+-- This should also show the difference
+test2 =
+  if firstLongCondition
+  then
+    if secondLongCondition
+    then result1
+    else result2
+  else alternativeResult

test/snapshots/ThenPlacementNewLine.input

@@ -0,0 +1,56 @@
+-- @format --then-new-line
+module ThenPlacementNewLine where
+
+-- Simple if-then-else
+simple = if condition then result else alternative
+
+-- Nested if-then-else
+nested = if a then b else if x then y else z
+
+-- Multi-line condition
+multilineCondition =
+  if someVeryLongConditionThatSpansMultipleLinesAndNeedsToWrap
+    then shortResult
+    else alternativeResult
+
+-- Multi-line then/else branches
+multilineBranches =
+  if condition
+    then do
+      action1
+      action2
+      result
+    else do
+      alternativeAction1
+      alternativeAction2
+      alternativeResult
+
+-- Complex nested case
+complexNested =
+  if firstCondition
+    then if secondCondition
+      then firstResult
+      else if thirdCondition
+        then secondResult
+        else thirdResult
+    else if fourthCondition
+      then fourthResult
+      else finalResult
+
+-- With guards
+withGuards x y
+  | condition = if guard then guardedResult else defaultResult
+  | otherwise = if alternativeGuard then alternativeResult else fallback
+
+-- In do blocks
+inDoBlock = do
+  value <- computation
+  if isValid value
+    then pure value
+    else throwError "Invalid value"
+
+-- With complex expressions
+complexExpressions =
+  if (someFunction arg1 arg2 >>= anotherFunction)
+    then (complexResult >>= transform >>= validate)
+    else (fallbackComputation >>= handleError)