MatchParentheses

input/src/main/scala-3/fix/MatchParenthesesTest.scala

@@ -0,0 +1,18 @@
+/*
+rule = MatchParentheses
+ */
+package fix
+
+trait MatchParenthesesTest {
+  def f1(x: List[Int]): Int = (x match {
+    case Nil => ","
+    case _ => x.mkString(",")
+  }).length
+
+  def g(s: String): String
+
+  def f2(x: List[Int]): Int = g(x match {
+    case Nil => ","
+    case _ => x.mkString(",")
+  }).length
+}

output/src/main/scala-3/fix/MatchParenthesesTest.scala

@@ -0,0 +1,15 @@
+package fix
+
+trait MatchParenthesesTest {
+  def f1(x: List[Int]): Int = x .match {
+    case Nil => ","
+    case _ => x.mkString(",")
+  }.length
+
+  def g(s: String): String
+
+  def f2(x: List[Int]): Int = g(x match {
+    case Nil => ","
+    case _ => x.mkString(",")
+  }).length
+}

rules/src/main/scala/fix/MatchParentheses.scala

@@ -0,0 +1,34 @@
+package fix
+
+import scala.meta.Term
+import scala.meta.XtensionClassifiable
+import scala.meta.XtensionCollectionLikeUI
+import scala.meta.tokens.Token
+import scalafix.Patch
+import scalafix.v1.SyntacticDocument
+import scalafix.v1.SyntacticRule
+import scalafix.v1.XtensionOptionPatch
+import scalafix.v1.XtensionSeqPatch
+
+class MatchParentheses extends SyntacticRule("MatchParentheses") {
+  override def fix(implicit doc: SyntacticDocument): Patch = {
+    doc.tree.collect { case t: Term.Match =>
+      PartialFunction
+        .condOpt(doc.tokens.filter(_.pos.start >= t.pos.end).take(2)) { case Seq(r: Token.RightParen, _: Token.Dot) =>
+          PartialFunction
+            .condOpt(doc.tokens.filter(_.pos.end <= t.pos.start).takeRight(2)) {
+              case Seq(n, l: Token.LeftParen) if !n.is[Token.Ident] =>
+                Seq(
+                  Patch.removeToken(l),
+                  t.tokens.collectFirst { case m: Token.KwMatch =>
+                    Patch.addLeft(m, ".")
+                  }.asPatch,
+                  Patch.removeToken(r)
+                ).asPatch
+            }
+            .asPatch
+        }
+        .asPatch
+    }.asPatch
+  }
+}