OrganizeImports: support Scala3 syntax as output

docs/rules/OrganizeImports.md

@@ -1342,16 +1342,17 @@ Enum: `Auto | Scala2 | Scala3`
 #### `Auto`
 
 Infer the dialect from compilation settings (Scala version or `-Xsource` when
-provided). This is safe only for sources that are not cross-compiled (see
-rationale below).
+provided). This is safe only for sources that are not cross-compiled and
+therefore it is NOT the default value (see rationale below).
 
 #### `Scala2`
 
 Use `_` as wildcard and `=>` for renames.
 
 #### `Scala3`
 
-Use `*` as wildcard and `as` for renames.
+Use `*` as wildcard and `as` for renames. Curly braces are omitted for importers
+with a single importee (including a rename, an unimport or a given).
 
 ### Default value
 
@@ -1374,11 +1375,16 @@ OrganizeImports {
 Before:
 
 ```scala
+import scala.collection.immutable.{List => L}
+import scala.collection.mutable.{Map, Buffer => _, Seq => S, _}
 ```
 
 After:
 
 ```scala
+import scala.collection.immutable.{List => L}
+import scala.collection.mutable.Map
+import scala.collection.mutable.{Buffer => _, Seq => S, _}
 ```
 
 #### `Scala3`  
@@ -1392,10 +1398,17 @@ OrganizeImports {
 Before:
 
 ```scala
+import scala.collection.immutable.{List => L}
+import scala.collection.mutable.{Map, Buffer => _, Seq => S, _}
+import scala.concurrent.ExecutionContext.Implicits.{given scala.concurrent.ExecutionContext}
 ```
 
 After:
 
 ```scala
+import scala.collection.immutable.List as L
+import scala.collection.mutable.Map
+import scala.collection.mutable.{Buffer as _, Seq as S, *}
+import scala.concurrent.ExecutionContext.Implicits.given scala.concurrent.ExecutionContext
 ```
 

scalafix-rules/src/main/scala/scalafix/internal/rule/OrganizeImports.scala

@@ -572,7 +572,12 @@ class OrganizeImports(
 
       importer match {
         case Importer(_, Importee.Wildcard() :: Nil) =>
-          syntax.patch(syntax.lastIndexOfSlice("._"), ".\u0001", 2)
+          val wildcardSyntax = Importee.Wildcard().syntax
+          syntax.patch(
+            syntax.lastIndexOfSlice(s".$wildcardSyntax"),
+            ".\u0001",
+            2
+          )
 
         case _ if importer.isCurlyBraced =>
           syntax
@@ -714,9 +719,48 @@ class OrganizeImports(
   private def importerSyntax(importer: Importer): String =
     importer.pos match {
       case pos: Position.Range =>
-        // Position found, implies that `importer` was directly parsed from the source code. Returns
-        // the original parsed text to preserve the original source level formatting.
-        pos.text
+        // Position found, implies that `importer` was directly parsed from the source code. Use
+        // the original parsed text to preserve the original source level formatting, but patch
+        // importee that have specific Scala 3 syntax.
+        val syntax = new StringBuilder(pos.text)
+        def patchSyntax(
+            t: Tree,
+            newSyntax: String,
+            stripEnclosingBraces: Boolean = false
+        ) = {
+          val start = t.pos.start - pos.start
+          syntax.replace(start, t.pos.end - pos.start, newSyntax)
+          val end = t.pos.start - pos.start + newSyntax.length
+
+          if (stripEnclosingBraces)
+            (
+              syntax.take(start).lastIndexOf('{'),
+              syntax.indexOf('}', end)
+            ) match {
+              case (from, to) if from != -1 && to != -1 =>
+                syntax.delete(end, to + 1)
+                syntax.delete(from, start)
+              case _ =>
+            }
+        }
+        val Importer(_, importees) = importer
+        val optionalBraces =
+          importees.length == 1 && targetDialect.allowAsForImportRename
+        // traverse & patch backwards to avoid shifting indices
+        importees.reverse.foreach {
+          case i @ Importee.Rename(_, _) =>
+            patchSyntax(i, i.copy().syntax, optionalBraces)
+          case i @ Importee.Unimport(_) =>
+            patchSyntax(i, i.copy().syntax, optionalBraces)
+          case i @ Importee.Wildcard() =>
+            patchSyntax(i, i.copy().syntax)
+          case i @ Importee.GivenAll() =>
+            patchSyntax(i, i.copy().syntax, importees.length == 1)
+          case i @ Importee.Given(_) =>
+            patchSyntax(i, i.copy().syntax, importees.length == 1)
+          case _ =>
+        }
+        syntax.toString
 
       case Position.None =>
         // Position not found, implies that `importer` is derived from certain existing import
@@ -742,7 +786,9 @@ class OrganizeImports(
     def isCurlyBraced: Boolean = {
       val importees @ Importees(_, renames, unimports, _, _, _) =
         importer.importees
-      renames.nonEmpty || unimports.nonEmpty || importees.length > 1
+
+      importees.length > 1 ||
+      ((renames.length == 1 || unimports.length == 1) && !targetDialect.allowAsForImportRename)
     }
 
     /**

scalafix-tests/input/src/main/scala-3/test/organizeImports/CoalesceImporteesGivensAndNames.scala

@@ -4,6 +4,7 @@ OrganizeImports {
   groupedImports = Keep
   coalesceToWildcardImportThreshold = 2
   removeUnused = false
+  targetDialect = Scala3
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala-3/test/organizeImports/CoalesceImporteesNoGivens.scala

@@ -4,6 +4,7 @@ OrganizeImports {
   groupedImports = Keep
   coalesceToWildcardImportThreshold = 2
   removeUnused = false
+  targetDialect = Scala3
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala-3/test/organizeImports/CoalesceImporteesNoGivensNoNames.scala

@@ -4,6 +4,7 @@ OrganizeImports {
   groupedImports = Keep
   coalesceToWildcardImportThreshold = 2
   removeUnused = false
+  targetDialect = Scala3
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala-3/test/organizeImports/CoalesceImporteesNoNames.scala

@@ -4,6 +4,7 @@ OrganizeImports {
   groupedImports = Keep
   coalesceToWildcardImportThreshold = 2
   removeUnused = false
+  targetDialect = Scala3
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala-3/test/organizeImports/DeduplicateGivenImportees.scala

@@ -1,6 +1,7 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala-3/test/organizeImports/ExpandGiven.scala

@@ -1,12 +1,13 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 
 import test.organizeImports.GivenImports.Beta
 import test.organizeImports.GivenImports.Alpha
-import test.organizeImports.GivenImports.{given Beta, given Alpha}
+import test.organizeImports.GivenImports.{given Beta, given test.organizeImports.GivenImports.Gamma, given Alpha}
 import scala.util.Either
 
 object ExpandGiven

scalafix-tests/input/src/main/scala-3/test/organizeImports/ExpandUnimportGiven.scala

@@ -1,6 +1,7 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala-3/test/organizeImports/GroupedGivenImportsMergeUnimports.scala

@@ -2,17 +2,18 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 
-import test.organizeImports.GivenImports._
-import test.organizeImports.GivenImports.{alpha => _, given}
+import test.organizeImports.GivenImports.*
+import test.organizeImports.GivenImports.{alpha as _, given}
 import test.organizeImports.GivenImports.{given Beta}
-import test.organizeImports.GivenImports.{gamma => _, given}
+import test.organizeImports.GivenImports.{gamma as _, given}
 import test.organizeImports.GivenImports.{given Zeta}
 
-import test.organizeImports.GivenImports2.{alpha => _}
-import test.organizeImports.GivenImports2.{beta => _}
+import test.organizeImports.GivenImports2.{alpha as _}
+import test.organizeImports.GivenImports2.beta as _
 import test.organizeImports.GivenImports2.{given Gamma}
 import test.organizeImports.GivenImports2.{given Zeta}
 

scalafix-tests/input/src/main/scala-3/test/organizeImports/GroupedImportsAggressiveMergeGivenAll.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = AggressiveMerge
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala-3/test/organizeImports/MergeGiven.scala

@@ -2,12 +2,14 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Scala3
  */
 package test.organizeImports
 
 import test.organizeImports.GivenImports.Beta
 import test.organizeImports.GivenImports.Alpha
 import test.organizeImports.GivenImports.{given Beta}
+import test.organizeImports.GivenImports.given test.organizeImports.GivenImports.Gamma
 import test.organizeImports.GivenImports.{given Alpha}
 import scala.util.Either
 

scalafix-tests/input/src/main/scala-3/test/organizeImports/MergeImportsFormatPreservingGiven.scala

@@ -0,0 +1,14 @@
+/*
+rules = [OrganizeImports]
+OrganizeImports.removeUnused = false
+OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Scala3
+ */
+
+package test.organizeImports
+
+import test.organizeImports.GivenImports.*
+import test.organizeImports.GivenImports.{ given Alpha, given Beta }
+import test.organizeImports.GivenImports2.{ given Gamma }
+
+object MergeImportsFormatPreservingGiven

scalafix-tests/input/src/main/scala/test/organizeImports/CoalesceImportees.scala

@@ -4,6 +4,7 @@ OrganizeImports {
   groupedImports = Keep
   coalesceToWildcardImportThreshold = 3
   removeUnused = false
+  targetDialect = Auto
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala/test/organizeImports/CurlyBracedSingleImportee.scala

@@ -1,10 +1,12 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 
 import scala.collection.{Map}
+import scala.collection.{Seq => _}
 import scala.collection.{Set => ImmutableSet}
 
 object CurlyBracedSingleImportee

scalafix-tests/input/src/main/scala/test/organizeImports/ExpandRelativeRootPackage.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.expandRelative = true
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/ExplodeImportsFormatPreserving.scala

@@ -2,11 +2,12 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Explode
+OrganizeImports.targetDialect = Auto
  */
 
 package test.organizeImports
 
 import test.organizeImports.ExplodeImports.FormatPreserving.g1.{ a, b }
-import test.organizeImports.ExplodeImports.FormatPreserving.g2.{ c => C, _ }
+import test.organizeImports.ExplodeImports.FormatPreserving.g2.{ c  =>  C, _ }
 
 object ExplodeImportsFormatPreserving

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsAggressiveMergeWildcard.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = AggressiveMerge
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsExplodeMixed.scala

@@ -1,6 +1,7 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsExplodeUnimport.scala

@@ -1,6 +1,7 @@
 /*
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsMergeDedup.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsMergeRenames.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsMergeUnimports.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/GroupedImportsMergeWildcard.scala

@@ -2,6 +2,7 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Auto
  */
 package test.organizeImports
 

scalafix-tests/input/src/main/scala/test/organizeImports/ImportsOrderKeep.scala

@@ -5,6 +5,7 @@ OrganizeImports {
   groupedImports = Keep
   importSelectorsOrder = Keep
   importsOrder = Keep
+  targetDialect = Auto
 }
  */
 package test.organizeImports

scalafix-tests/input/src/main/scala/test/organizeImports/ImportsOrderSymbolsFirst.scala

@@ -5,6 +5,7 @@ OrganizeImports {
   groupedImports = Keep
   importSelectorsOrder = Keep
   importsOrder = SymbolsFirst
+  targetDialect = Auto
 }
  */
 package test.organizeImports
@@ -15,6 +16,9 @@ import scala.concurrent.duration
 import scala.concurrent.{Promise, Future}
 
 import test.organizeImports.QuotedIdent.`a.b`.`{ d }`.e
+import test.organizeImports.QuotedIdent.`a.b`.`{ d }`.{  e => E  }
+import test.organizeImports.QuotedIdent.`a.b`
+import test.organizeImports.QuotedIdent.{`a.b` => ab}
 import test.organizeImports.QuotedIdent.`a.b`.{c => _, _}
 import test.organizeImports.QuotedIdent._
 

scalafix-tests/input/src/main/scala/test/organizeImports/MergeImportsFormatPreserving.scala

@@ -2,11 +2,12 @@
 rules = [OrganizeImports]
 OrganizeImports.removeUnused = false
 OrganizeImports.groupedImports = Merge
+OrganizeImports.targetDialect = Auto
  */
 
 package test.organizeImports
 
-import test.organizeImports.MergeImports.FormatPreserving.g1.{ a, b }
+import test.organizeImports.MergeImports.FormatPreserving.g1.{ a, b => B }
 import test.organizeImports.MergeImports.FormatPreserving.g2._
 import test.organizeImports.MergeImports.FormatPreserving.g2.{ d => D }