Router: no break after => in lambda w/ type

Otherwise, it looks like a "fewer braces" invocation and will be parsed as such.
scalameta · Nov 10, 2024 · 049bfe5 · 049bfe5
1 parent f455891
commit 049bfe5
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Showing 8 changed files with 91 additions and 66 deletions.
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala
@@ -285,7 +285,7 @@ class Router(formatOps: FormatOps) {
               else Some(false)
             (arrow, 0, nlOnly)
           case (t: Term.FunctionTerm) :: Nil =>
-            val arrow = getFuncArrow(lastLambda(t)).getOrElse(getLast(t))
+            val arrow = lastLambda(t).flatMap(getFuncArrow).getOrElse(getLast(t))
             val nlOnly =
               if (style.newlines.alwaysBeforeCurlyLambdaParams) Some(true)
               else if (
@@ -527,27 +527,29 @@ class Router(formatOps: FormatOps) {
             case _ => false
           }) =>
         val leftFunc = leftOwner.asInstanceOf[Term.FunctionTerm]
-        val (afterCurlySpace, afterCurlyNewlines) =
-          getSpaceAndNewlineAfterCurlyLambda(newlines)
         def spaceSplitBase(implicit line: FileLine): Split = Split(Space, 0)
-        val spaceSplit = leftFunc.body match {
-          case _: Term.FunctionTerm => spaceSplitBase
-          case Term.Block((_: Term.FunctionTerm) :: Nil)
-              if !nextNonComment(ft).right.is[T.LeftBrace] => spaceSplitBase
-          case _ if afterCurlySpace && {
-                style.newlines.fold || !rightOwner.is[Defn]
-              } =>
-            val exp = nextNonCommentSameLine(getLastNonTrivial(leftFunc.body))
-              .left
-            spaceSplitBase.withSingleLine(exp, noSyntaxNL = true)
-          case _ => Split.ignored
-        }
-        val (endIndent, expiresOn) = functionExpire(leftFunc)
-        Seq(
-          spaceSplit,
-          Split(afterCurlyNewlines, 1)
-            .withIndent(style.indent.main, endIndent, expiresOn),
-        )
+        if (canBreakAfterFuncArrow(leftFunc)) {
+          val (afterCurlySpace, afterCurlyNewlines) =
+            getSpaceAndNewlineAfterCurlyLambda(newlines)
+          val spaceSplit = leftFunc.body match {
+            case _: Term.FunctionTerm => spaceSplitBase
+            case Term.Block((_: Term.FunctionTerm) :: Nil)
+                if !nextNonComment(ft).right.is[T.LeftBrace] => spaceSplitBase
+            case _ if afterCurlySpace && {
+                  style.newlines.fold || !rightOwner.is[Defn]
+                } =>
+              val exp = nextNonCommentSameLine(getLastNonTrivial(leftFunc.body))
+                .left
+              spaceSplitBase.withSingleLine(exp, noSyntaxNL = true)
+            case _ => Split.ignored
+          }
+          val (endIndent, expiresOn) = functionExpire(leftFunc)
+          Seq(
+            spaceSplit,
+            Split(afterCurlyNewlines, 1)
+              .withIndent(style.indent.main, endIndent, expiresOn),
+          )
+        } else Seq(spaceSplitBase)
 
       case FormatToken(_: T.RightArrow | _: T.ContextArrow, right, _)
           if (leftOwner match {

diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/util/TreeOps.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/util/TreeOps.scala
@@ -351,14 +351,36 @@ object TreeOps {
     math.max(res, treeDepth(t))
   }
 
+  final def canBreakAfterFuncArrow(func: Term.FunctionTerm)(implicit
+      ftoks: FormatTokens,
+      style: ScalafmtConfig,
+  ): Boolean = !style.dialect.allowFewerBraces || {
+    val params = func.paramClause
+    params.values match {
+      case param :: Nil => param.decltpe match {
+          case Some(_: Type.Name) => ftoks.isEnclosedInMatching(params)
+          case _ => true
+        }
+      case _ => true
+    }
+  }
+
   @tailrec
   final def lastLambda(
       first: Term.FunctionTerm,
-  )(implicit ftoks: FormatTokens): Term.FunctionTerm = first.body match {
-    case child: Term.FunctionTerm => lastLambda(child)
-    case b @ Term.Block((child: Term.FunctionTerm) :: Nil)
-        if !ftoks.getHead(b).left.is[Token.LeftBrace] => lastLambda(child)
-    case _ => first
+      res: Option[Term.FunctionTerm] = None,
+  )(implicit
+      ftoks: FormatTokens,
+      style: ScalafmtConfig,
+  ): Option[Term.FunctionTerm] = {
+    val nextres = if (canBreakAfterFuncArrow(first)) Some(first) else res
+    first.body match {
+      case child: Term.FunctionTerm => lastLambda(child, nextres)
+      case b @ Term.Block((child: Term.FunctionTerm) :: Nil)
+          if !ftoks.getHead(b).left.is[Token.LeftBrace] =>
+        lastLambda(child, nextres)
+      case _ => nextres
+    }
   }
 
   @inline

diff --git a/...-community/scala3/src/test/scala/org/scalafmt/community/scala3/CommunityScala3Suite.scala b/...-community/scala3/src/test/scala/org/scalafmt/community/scala3/CommunityScala3Suite.scala
@@ -17,7 +17,7 @@ class CommunityScala3_2Suite extends CommunityScala3Suite("scala-3.2") {
 
 class CommunityScala3_3Suite extends CommunityScala3Suite("scala-3.3") {
 
-  override protected def totalStatesVisited: Option[Int] = Some(34839832)
+  override protected def totalStatesVisited: Option[Int] = Some(34839737)
 
   override protected def builds = Seq(getBuild("3.3.3", dialects.Scala33, 861))
 

diff --git a/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces.stat b/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces.stat
@@ -7556,11 +7556,11 @@ object Build:
      .settings(
        generateScalaDocumentation := Def.inputTaskDyn {
          val outputDirOverride =
-           extraArgs.headOption.fold(identity[GenerationConfig](_)) {
-             newDir => config: GenerationConfig => config.add(OutputDir(newDir))
+           extraArgs.headOption.fold(identity[GenerationConfig](_)) { newDir =>
+             config: GenerationConfig => config.add(OutputDir(newDir))
            }
-         val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) {
-           _ => config: GenerationConfig => config.remove[SiteRoot]
+         val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
+           config: GenerationConfig => config.remove[SiteRoot]
          }
        }.evaluated
      )
diff --git a/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_fold.stat b/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_fold.stat
@@ -7264,15 +7264,14 @@ object Build {
     )
 }
 >>>
-Idempotency violated
-=> Diff (- obtained, + expected)
-          }
--       val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
--         config: GenerationConfig =>
--            config.remove[SiteRoot]
--       }
-+       val justAPI = justAPIArg
-+         .fold(identity[GenerationConfig](_)) { _ => config: GenerationConfig =>
-+           config.remove[SiteRoot]
-+         }
-      }.evaluated)
+object Build:
+   lazy val scaladoc = project.in(file("scaladoc"))
+     .settings(generateScalaDocumentation := Def.inputTaskDyn {
+       val outputDirOverride = extraArgs.headOption
+         .fold(identity[GenerationConfig](_)) { newDir =>
+           config: GenerationConfig => config.add(OutputDir(newDir))
+         }
+       val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
+         config: GenerationConfig => config.remove[SiteRoot]
+       }
+     }.evaluated)
diff --git a/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_keep.stat b/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_keep.stat
@@ -7584,11 +7584,11 @@ object Build:
    settings(
      generateScalaDocumentation := Def.inputTaskDyn {
        val outputDirOverride =
-         extraArgs.headOption.fold(identity[GenerationConfig](_)) {
-           newDir => config: GenerationConfig => config.add(OutputDir(newDir))
+         extraArgs.headOption.fold(identity[GenerationConfig](_)) { newDir =>
+           config: GenerationConfig => config.add(OutputDir(newDir))
          }
-       val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) {
-         _ => config: GenerationConfig => config.remove[SiteRoot]
+       val justAPI = justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
+         config: GenerationConfig => config.remove[SiteRoot]
        }
      }.evaluated
    )
diff --git a/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_unfold.stat b/scalafmt-tests/shared/src/test/resources/scala3/OptionalBraces_unfold.stat
@@ -7859,21 +7859,23 @@ object Build {
     )
 }
 >>>
-Idempotency violated
-=> Diff (- obtained, + expected)
-                  .headOption
--                 .fold(identity[GenerationConfig](_)) { newDir =>
--                   config: GenerationConfig =>
--                      config.add(OutputDir(newDir))
-+                 .fold(identity[GenerationConfig](_)) {
-+                   newDir => config: GenerationConfig =>
-+                     config.add(OutputDir(newDir))
-                  }
-              val justAPI =
--               justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
--                 config: GenerationConfig =>
--                    config.remove[SiteRoot]
-+               justAPIArg.fold(identity[GenerationConfig](_)) {
-+                 _ => config: GenerationConfig =>
-+                   config.remove[SiteRoot]
-                }
+object Build:
+   lazy val scaladoc = project
+     .in(file("scaladoc"))
+     .settings(
+       generateScalaDocumentation :=
+         Def
+           .inputTaskDyn {
+             val outputDirOverride =
+               extraArgs
+                 .headOption
+                 .fold(identity[GenerationConfig](_)) { newDir =>
+                   config: GenerationConfig => config.add(OutputDir(newDir))
+                 }
+             val justAPI =
+               justAPIArg.fold(identity[GenerationConfig](_)) { _ =>
+                 config: GenerationConfig => config.remove[SiteRoot]
+               }
+           }
+           .evaluated
+     )
diff --git a/scalafmt-tests/shared/src/test/scala/org/scalafmt/FormatTests.scala b/scalafmt-tests/shared/src/test/scala/org/scalafmt/FormatTests.scala
@@ -137,7 +137,7 @@ class FormatTests extends FunSuite with CanRunTests with FormatAssertions {
     val explored = Debug.explored.get()
     logger.debug(s"Total explored: $explored")
     if (!onlyUnit && !onlyManual)
-      assertEquals(explored, 1119018, "total explored")
+      assertEquals(explored, 1116417, "total explored")
     val results = debugResults.result()
     // TODO(olafur) don't block printing out test results.
     // I don't want to deal with scalaz's Tasks :'(