From 415dc2ac78697d648297084b638e37cbd7bac716 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Tue, 2 Jan 2024 06:41:20 -0800
Subject: [PATCH] RedundantParens: exclude case of trailing commas

---
 .../scalafmt/rewrite/RedundantParens.scala    |  4 ++-
 .../resources/rewrite/RedundantParens.stat    | 27 ++++++++++++-------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantParens.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantParens.scala
index 99713d6b47..9445cfaca8 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantParens.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantParens.scala
@@ -86,7 +86,9 @@ class RedundantParens(ftoks: FormatTokens) extends FormatTokensRewrite.Rule {
       style: ScalafmtConfig
   ): Option[(Replacement, Replacement)] =
     ft.right match {
-      case _: Token.RightParen if left.how eq ReplacementType.Remove =>
+      case _: Token.RightParen
+          if (left.how eq ReplacementType.Remove) && // check trailing comma
+            !ftoks.prevNonComment(ft).left.is[Token.Comma] =>
         Some((left, removeToken))
       case _ => None
     }
diff --git a/scalafmt-tests/src/test/resources/rewrite/RedundantParens.stat b/scalafmt-tests/src/test/resources/rewrite/RedundantParens.stat
index 843c478061..15c75c64d2 100644
--- a/scalafmt-tests/src/test/resources/rewrite/RedundantParens.stat
+++ b/scalafmt-tests/src/test/resources/rewrite/RedundantParens.stat
@@ -1334,12 +1334,15 @@ object A {
       Option(""),
     ).map(identity)}
 >>>
-test does not parse
 object A {
   def test =
-    foo,
+    (
+      foo,
+  )
   def test =
-    Option(""), .map(identity)
+    (
+      Option(""),
+    ).map(identity)
 }
 <<< #3743 trailingCommas = never
 rewrite.trailingCommas.style = never
@@ -1354,12 +1357,15 @@ object A {
       Option(""),
     ).map(identity)}
 >>>
-test does not parse
 object A {
   def test =
-    foo,
+    (
+      foo,
+  )
   def test =
-    Option(""), .map(identity)
+    (
+      Option(""),
+    ).map(identity)
 }
 <<< #3743 trailingCommas = keep
 rewrite.trailingCommas.style = keep
@@ -1374,10 +1380,13 @@ object A {
       Option(""),
     ).map(identity)}
 >>>
-test does not parse
 object A {
   def test =
-    foo,
+    (
+      foo,
+  )
   def test =
-    Option(""), .map(identity)
+    (
+      Option(""),
+    ).map(identity)
 }