From a2bfb510d688342c1e9883e86acb34eb46782a99 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Thu, 21 Nov 2024 14:51:14 -0800
Subject: [PATCH] TreeOps: a braceless `match` is like fewer-braces

---
 .../org/scalafmt/internal/FormatOps.scala      |  2 +-
 .../scalafmt/internal/TreeSyntacticGroup.scala |  2 +-
 .../main/scala/org/scalafmt/util/TreeOps.scala |  1 +
 .../resources/rewrite/RedundantParens.stat     | 18 ++++++++++++------
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
index 5fb35de125..7f58c01752 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
@@ -401,7 +401,7 @@ class FormatOps(
         val mod =
           if (ft.noBreak || !okToBreak) spaceMod
           else Newline2x(isFullInfixEnclosed && ft.hasBlankLine)
-        val split = Split(mod, 0)
+        def split(implicit fl: FileLine) = Split(mod, 0)
         if (isBeforeOp && isFewerBracesRhs(app.arg)) Seq(split)
         else Seq(InfixSplits.withNLIndent(split, app, fullInfix))
       }
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/TreeSyntacticGroup.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/TreeSyntacticGroup.scala
index 08db380cf6..5370d5e47a 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/TreeSyntacticGroup.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/TreeSyntacticGroup.scala
@@ -19,6 +19,7 @@ object TreeSyntacticGroup {
     case _: Term.Xml => g.Term.SimpleExpr1
     case _: Term.Apply => g.Term.SimpleExpr1
     case _: Term.ApplyType => g.Term.SimpleExpr1
+    case _: Term.SelectMatch => g.Term.SimpleExpr1
     case t: Term.ApplyInfix => g.Term.InfixExpr(t.op.value)
     case t: Term.ApplyUnary => g.Term.PrefixExpr(t.op.value)
     case _: Term.Assign => g.Term.Expr1
@@ -34,7 +35,6 @@ object TreeSyntacticGroup {
     case _: Term.TryClause => g.Term.Expr1
     case _: Term.FunctionTerm => g.Term.Expr
     case _: Term.PolyFunction => g.Term.Expr
-    case _: Term.SelectMatch => g.Term.SimpleExpr
     case _: Term.PartialFunction => g.Term.SimpleExpr
     case _: Term.While => g.Term.Expr1
     case _: Term.Do => g.Term.Expr1
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
index 424dd3a310..55d51d9084 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/util/TreeOps.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/util/TreeOps.scala
@@ -888,6 +888,7 @@ object TreeOps {
           case t: Term.ApplyInfix => isFewerBracesLhs(t.argClause)
           case _ => false
         }
+      case t: Tree.WithCasesBlock => !ftoks.isEnclosedInMatching(t.casesBlock)
       case _ => false
     })
 
diff --git a/scalafmt-tests/shared/src/test/resources/rewrite/RedundantParens.stat b/scalafmt-tests/shared/src/test/resources/rewrite/RedundantParens.stat
index ec0f3af349..289ed95697 100644
--- a/scalafmt-tests/shared/src/test/resources/rewrite/RedundantParens.stat
+++ b/scalafmt-tests/shared/src/test/resources/rewrite/RedundantParens.stat
@@ -554,12 +554,18 @@ object a {
   )
 }
 >>>
-Idempotency violated
-=> Diff (- obtained, + expected)
-     case false => false
--    + e
-+  + e
-   val b = c + (d match
+object a {
+  val b = c + d.match
+    case true  => true
+    case false => false
+  val b = c + d.match
+    case true  => true
+    case false => false
+  + e
+  val b = c + (d match
+    case true  => true
+    case false => false)
+}
 <<< #2194 6 match with parens, dot and no braces, !infixSide
 runner.dialect = scala3
 rewrite.redundantParens.infixSide = null