Router: consistent if-else block format for fold

scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala

@@ -315,25 +315,6 @@ class Router(formatOps: FormatOps) {
         val lambdaExpire =
           if (lambdaArrow eq null) null else nextNonCommentSameLine(lambdaArrow)
 
-        def getSingleLinePolicy = {
-          val needBreak = close.right match {
-            case _: T.KwElse => close.rightOwner match {
-                case p: Term.If => p.thenp eq leftOwner
-                case _ => false
-              }
-            case _: T.KwCatch => close.rightOwner match {
-                case p: Term.TryClause => p.expr eq leftOwner
-                case _ => false
-              }
-            case _: T.KwFinally => close.rightOwner match {
-                case p: Term.TryClause => (p.expr eq leftOwner) ||
-                  p.catchClause.contains(leftOwner)
-                case _ => false
-              }
-            case _ => false
-          }
-          Policy ? needBreak && decideNewlinesOnlyAfterClose(close)
-        }
         def getClassicSingleLineDecisionOpt =
           if (noBreak()) Some(true) else None
 
@@ -381,11 +362,28 @@ class Router(formatOps: FormatOps) {
         val singleLineSplitOpt = {
           if (slbParensExclude eq null) None else singleLineDecisionOpt
         }.map { sld =>
-          val sldPolicy = getSingleLinePolicy
+          val ownerIfNeedBreakAfterClose = close.right match {
+            case _: T.KwElse => close.rightOwner match {
+                case p: Term.If if p.thenp eq leftOwner => Some(p)
+                case _ => None
+              }
+            case _: T.KwCatch => close.rightOwner match {
+                case p: Term.TryClause if p.expr eq leftOwner => Some(p)
+                case _ => None
+              }
+            case _: T.KwFinally => close.rightOwner match {
+                case p: Term.TryClause
+                    if (p.expr eq leftOwner) ||
+                      p.catchClause.contains(leftOwner) => Some(p)
+                case _ => None
+              }
+            case _ => None
+          }
           val expire = leftOwner.parent match {
             case Some(p: Term.ForYield)
-                if !sld && sldPolicy.isEmpty && style.newlines.fold &&
-                  leftOwner.is[Term.EnumeratorsBlock] => getLast(p)
+                if !sld && ownerIfNeedBreakAfterClose.isEmpty &&
+                  style.newlines.fold && leftOwner.is[Term.EnumeratorsBlock] =>
+              getLast(p)
             case _ if style.newlines.isBeforeOpenParenCallSite => close
             case _ => getSlbEndOnLeft(close)
           }
@@ -404,6 +402,22 @@ class Router(formatOps: FormatOps) {
             else Policy.RelayOnSplit((s, _) => s.isNL)(slbParensPolicy)(
               Policy.onLeft(close, "BracesToParensFailed") { case _ => Nil },
             )
+          val sldPolicy = ownerIfNeedBreakAfterClose.map { p =>
+            if (style.newlines.fold) {
+              val pend = getSlbEndOnLeft(getLast(p))
+              def pendSlb(s: Split) = s
+                .withSingleLine(pend, noSyntaxNL = true, extend = true)
+              Policy.End <= close ==>
+                Policy.onRight(close, s"RB-ELSE[${pend.idx}]") {
+                  case Decision(`close`, ss) =>
+                    if (ss.exists(_.isNL)) ss
+                      .map(s => if (s.isNL) s else pendSlb(s))
+                    else ss.flatMap { s =>
+                      Seq(pendSlb(s), s.withMod(Newline).withPenalty(1))
+                    }
+                }
+            } else decideNewlinesOnlyAfterClose(close)
+          }
           Split(slbMod, 0).withSingleLine(
             expire,
             exclude = exclude,

scalafmt-tests-community/intellij/src/test/scala/org/scalafmt/community/intellij/CommunityIntellijScalaSuite.scala

@@ -13,7 +13,7 @@ abstract class CommunityIntellijScalaSuite(name: String)
 class CommunityIntellijScala_2024_2_Suite
     extends CommunityIntellijScalaSuite("intellij-scala-2024.2") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(57952816)
+  override protected def totalStatesVisited: Option[Int] = Some(57957808)
 
   override protected def builds = Seq(getBuild(
     "2024.2.28",
@@ -51,7 +51,7 @@ class CommunityIntellijScala_2024_2_Suite
 class CommunityIntellijScala_2024_3_Suite
     extends CommunityIntellijScalaSuite("intellij-scala-2024.3") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(58169519)
+  override protected def totalStatesVisited: Option[Int] = Some(58174471)
 
   override protected def builds = Seq(getBuild(
     "2024.3.4",

scalafmt-tests-community/scala2/src/test/scala/org/scalafmt/community/scala2/CommunityScala2Suite.scala

@@ -9,7 +9,7 @@ abstract class CommunityScala2Suite(name: String)
 
 class CommunityScala2_12Suite extends CommunityScala2Suite("scala-2.12") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(42556059)
+  override protected def totalStatesVisited: Option[Int] = Some(42560182)
 
   override protected def builds =
     Seq(getBuild("v2.12.20", dialects.Scala212, 1277))
@@ -18,7 +18,7 @@ class CommunityScala2_12Suite extends CommunityScala2Suite("scala-2.12") {
 
 class CommunityScala2_13Suite extends CommunityScala2Suite("scala-2.13") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(53056214)
+  override protected def totalStatesVisited: Option[Int] = Some(53060139)
 
   override protected def builds =
     Seq(getBuild("v2.13.14", dialects.Scala213, 1287))

scalafmt-tests-community/scala3/src/test/scala/org/scalafmt/community/scala3/CommunityScala3Suite.scala

@@ -9,15 +9,15 @@ abstract class CommunityScala3Suite(name: String)
 
 class CommunityScala3_2Suite extends CommunityScala3Suite("scala-3.2") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(39245403)
+  override protected def totalStatesVisited: Option[Int] = Some(39246875)
 
   override protected def builds = Seq(getBuild("3.2.2", dialects.Scala32, 791))
 
 }
 
 class CommunityScala3_3Suite extends CommunityScala3Suite("scala-3.3") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(42431405)
+  override protected def totalStatesVisited: Option[Int] = Some(42432863)
 
   override protected def builds = Seq(getBuild("3.3.3", dialects.Scala33, 861))
 

scalafmt-tests-community/spark/src/test/scala/org/scalafmt/community/spark/CommunitySparkSuite.scala

@@ -9,7 +9,7 @@ abstract class CommunitySparkSuite(name: String)
 
 class CommunitySpark3_4Suite extends CommunitySparkSuite("spark-3.4") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(86350328)
+  override protected def totalStatesVisited: Option[Int] = Some(86399848)
 
   override protected def builds =
     Seq(getBuild("v3.4.1", dialects.Scala213, 2585))
@@ -18,7 +18,7 @@ class CommunitySpark3_4Suite extends CommunitySparkSuite("spark-3.4") {
 
 class CommunitySpark3_5Suite extends CommunitySparkSuite("spark-3.5") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(91352348)
+  override protected def totalStatesVisited: Option[Int] = Some(91404596)
 
   override protected def builds =
     Seq(getBuild("v3.5.3", dialects.Scala213, 2756))

scalafmt-tests/shared/src/test/resources/newlines/source_classic.stat

@@ -11201,3 +11201,51 @@ extends SomeBaseClass
 with SomeTrait
 >>>
 class SomeClass(a: Int, b: Double, c: String) extends SomeBaseClass with SomeTrait
+<<< if-else with one block, short
+maxColumn = 40
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) {
+    preFork = false; false
+  } else true
+
+  if (s.costWithPenalty <= 0) true
+  else { preFork = false; false }
+}
+<<< if-else with one block, medium
+maxColumn = 60
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false }
+  else true
+
+  if (s.costWithPenalty <= 0) true
+  else { preFork = false; false }
+}
+<<< if-else with one block, long
+maxColumn = 80
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false }
+  else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}

scalafmt-tests/shared/src/test/resources/newlines/source_fold.stat

@@ -16,8 +16,7 @@ println("bbb") } else c
 }
 >>>
 object a {
-  if (a) { println("bbb") }
-  else c
+  if (a) { println("bbb") } else c
 }
 <<< 1.3: block, if, non-egyptian curlies
 object a {
@@ -31,8 +30,7 @@ c
 }}
 >>>
 object a {
-  if (a) { println("bbb") }
-  else { c }
+  if (a) { println("bbb") } else { c }
 }
 <<< 1.4: block #1043
 object a {
@@ -252,12 +250,8 @@ object a {
 >>>
 object a {
   val ok1 = if (a > 10) Some(a) else None
-  val ok2 =
-    if (a > 10) { Some(a) }
-    else { None }
-  val ok3 =
-    if (aaaa > 10000) { Some(aaaa) }
-    else { None }
+  val ok2 = if (a > 10) { Some(a) } else { None }
+  val ok3 = if (aaaa > 10000) { Some(aaaa) } else { None }
 }
 <<< 2.7 #1747: one line without else
 maxColumn = 60
@@ -296,12 +290,8 @@ object a {
 >>>
 object a {
   val ok1 = if (a > 10) Some(a) else None
-  val ok2 =
-    if (a > 10) { Some(a) }
-    else { None }
-  val ok3 =
-    if (aaaa > 10000) { Some(aaaa) }
-    else { None }
+  val ok2 = if (a > 10) { Some(a) } else { None }
+  val ok3 = if (aaaa > 10000) { Some(aaaa) } else { None }
 }
 <<< 2.9 #1747: split on else
 maxColumn = 60
@@ -319,12 +309,8 @@ object a {
 >>>
 object a {
   val ok1 = if (a > 10) Some(a) else None
-  val ok2 =
-    if (a > 10) { Some(a) }
-    else { None }
-  val ok3 =
-    if (aaaa > 10000) { Some(aaaa) }
-    else { None }
+  val ok2 = if (a > 10) { Some(a) } else { None }
+  val ok3 = if (aaaa > 10000) { Some(aaaa) } else { None }
 }
 <<< 2.10 #1747: split on then without else
 maxColumn = 60
@@ -357,12 +343,8 @@ object a {
 >>>
 object a {
   val ok1 = if (a > 10) Some(a) else None
-  val ok2 =
-    if (a > 10) { Some(a) }
-    else { None }
-  val ok3 =
-    if (aaaa > 10000) { Some(aaaa) }
-    else { None }
+  val ok2 = if (a > 10) { Some(a) } else { None }
+  val ok3 = if (aaaa > 10000) { Some(aaaa) } else { None }
 }
 <<< 2.12 #1747: split on if without else
 maxColumn = 60
@@ -6008,8 +5990,7 @@ class Foo {
 >>>
 class Foo {
   val foo =
-    if (true) { "" }
-    else { "a" }
+    if (true) { "" } else { "a" }
   val foo = if (true) "" else "a"
   val foo = if (true) "" else "a"
   val foo =
@@ -6035,8 +6016,7 @@ class Foo() {
 >>>
 class Foo() {
   def ok: Boolean =
-    if (1 == 1) { true }
-    else false
+    if (1 == 1) { true } else false
 
   def notOK: Boolean =
     if (1 == 1) {
@@ -10467,3 +10447,50 @@ extends SomeBaseClass
 with SomeTrait
 >>>
 class SomeClass(a: Int, b: Double, c: String) extends SomeBaseClass with SomeTrait
+<<< if-else with one block, short
+maxColumn = 40
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) {
+    preFork = false; false
+  } else true
+
+  if (s.costWithPenalty <= 0) true
+  else { preFork = false; false }
+}
+<<< if-else with one block, medium
+maxColumn = 60
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false }
+  else true
+
+  if (s.costWithPenalty <= 0) true
+  else { preFork = false; false }
+}
+<<< if-else with one block, long
+maxColumn = 80
+===
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}
+>>>
+object a {
+  if (s.costWithPenalty > 0) { preFork = false; false } else true
+
+  if (s.costWithPenalty <= 0) true else { preFork = false; false }
+}