OrganizeImports: use new Scala 3 on Scala 3 sources

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

@@ -5,6 +5,7 @@ import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
 import scala.util.Try
 
+import scala.meta.Dialect
 import scala.meta.Import
 import scala.meta.Importee
 import scala.meta.Importee.GivenAll
@@ -28,6 +29,7 @@ import metaconfig.ConfEncoder
 import metaconfig.ConfOps
 import metaconfig.Configured
 import metaconfig.internal.ConfGet
+import scalafix.internal.config.ScalaVersion
 import scalafix.internal.rule.ImportMatcher.*
 import scalafix.internal.rule.ImportMatcher.---
 import scalafix.internal.rule.ImportMatcher.parse
@@ -43,8 +45,10 @@ import scalafix.v1.SymbolInformation
 import scalafix.v1.XtensionSeqPatch
 import scalafix.v1.XtensionTreeScalafix
 
-class OrganizeImports(config: OrganizeImportsConfig)
-    extends SemanticRule("OrganizeImports") {
+class OrganizeImports(
+    config: OrganizeImportsConfig,
+    implicit val dialect: Dialect
+) extends SemanticRule("OrganizeImports") {
   import OrganizeImports._
   import ImportMatcher._
 
@@ -58,7 +62,7 @@ class OrganizeImports(config: OrganizeImportsConfig)
   private val diagnostics: ArrayBuffer[Diagnostic] =
     ArrayBuffer.empty[Diagnostic]
 
-  def this() = this(OrganizeImportsConfig())
+  def this() = this(OrganizeImportsConfig(), Dialect.current)
 
   override def isLinter: Boolean = true
 
@@ -564,7 +568,12 @@ class OrganizeImports(config: OrganizeImportsConfig)
 
       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
@@ -685,6 +694,122 @@ class OrganizeImports(config: OrganizeImportsConfig)
 
     Patch.addLeft(token, indented mkString "\n")
   }
+
+  private def prettyPrintImportGroup(group: Seq[Importer]): String = {
+    group
+      .map(i => "import " + importerSyntax(i))
+      .mkString("\n")
+  }
+
+  /**
+   * HACK: The Scalafix pretty-printer decides to add spaces after open and
+   * before close braces in imports with multiple importees, i.e., `import a.{
+   * b, c }` instead of `import a.{b, c}`. On the other hand, renames are
+   * pretty-printed without the extra spaces, e.g., `import a.{b => c}`. This
+   * behavior is not customizable and makes ordering imports by ASCII order
+   * complicated.
+   *
+   * This function removes the unwanted spaces as a workaround. In cases where
+   * users do want the inserted spaces, Scalafmt should be used after running
+   * the `OrganizeImports` rule.
+   */
+  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. 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 && dialect.allowAsForImportRename
+        // traverse & patch backwards to avoid shifting indices
+        importees.reverse.foreach {
+          case i @ Importee.Rename(from, to) =>
+            patchSyntax(i, i.copy().syntax, optionalBraces)
+          case i @ Importee.Unimport(name) =>
+            patchSyntax(i, i.copy().syntax, optionalBraces)
+          case i @ Importee.Wildcard() =>
+            patchSyntax(i, i.copy().syntax)
+          case _ =>
+        }
+        syntax.toString
+
+      case Position.None =>
+        // Position not found, implies that `importer` is derived from certain existing import
+        // statement(s). Pretty-prints it.
+        val syntax = importer.syntax
+
+        // NOTE: We need to check whether the input importer is curly braced first and then replace
+        // the first "{ " and the last " }" if any. Naive string replacement is insufficient, e.g.,
+        // a quoted-identifier like "`{ d }`" may cause broken output.
+        (importer.isCurlyBraced, syntax lastIndexOfSlice " }") match {
+          case (_, -1) =>
+            syntax
+          case (true, index) =>
+            syntax.patch(index, "}", 2).replaceFirst("\\{ ", "{")
+          case _ =>
+            syntax
+        }
+    }
+
+  implicit private class ImporterExtension(importer: Importer) {
+
+    /** Checks whether the `Importer` is curly-braced when pretty-printed. */
+    def isCurlyBraced: Boolean = {
+      val importees @ Importees(_, renames, unimports, _, _, _) =
+        importer.importees
+
+      importees.length > 1 ||
+      ((renames.length == 1 || unimports.length == 1) && !dialect.allowAsForImportRename)
+    }
+
+    /**
+     * Returns an `Importer` with all the `Importee`s that are selected from the
+     * input `Importer` and satisfy a predicate. If all the `Importee`s are
+     * selected, the input `Importer` instance is returned to preserve the
+     * original source level formatting. If none of the `Importee`s are
+     * selected, returns a `None`.
+     */
+    def filterImportees(f: Importee => Boolean): Option[Importer] = {
+      val filtered = importer.importees filter f
+      if (filtered.length == importer.importees.length) Some(importer)
+      else if (filtered.isEmpty) None
+      else Some(importer.copy(importees = filtered))
+    }
+
+    /** Returns true if the `Importer` contains a standalone wildcard. */
+    def hasWildcard: Boolean = {
+      val Importees(_, _, unimports, _, _, wildcard) = importer.importees
+      unimports.isEmpty && wildcard.nonEmpty
+    }
+
+    /** Returns true if the `Importer` contains a standalone given wildcard. */
+    def hasGivenAll: Boolean = {
+      val Importees(_, _, unimports, _, givenAll, _) = importer.importees
+      unimports.isEmpty && givenAll.nonEmpty
+    }
+  }
 }
 
 object OrganizeImports {
@@ -717,8 +842,29 @@ object OrganizeImports {
       }
     }
 
+    // TODO: add an option to force a dialect with many tests
+    val maybeDialect = ScalaVersion.from(scalaVersion).map { scalaVersion =>
+      def extractSuffixForScalacOption(prefix: String) = {
+        scalacOptions
+          .filter(_.startsWith(prefix))
+          .lastOption
+          .map(_.stripPrefix(prefix))
+      }
+
+      // We only lookup the Scala 2 option (Scala 3 is `-source`), as the latest Scala 3
+      // dialect is used no matter what the actual minor version is anyway, and as of now,
+      // the pretty printer is just more permissive with the latest dialect.
+      val sourceScalaVersion =
+        extractSuffixForScalacOption("-Xsource:")
+          .flatMap(ScalaVersion.from(_).toOption)
+
+      scalaVersion.dialect(sourceScalaVersion)
+    }
+
     if (!conf.removeUnused || hasWarnUnused)
-      Configured.ok(new OrganizeImports(conf))
+      Configured.ok(
+        new OrganizeImports(conf, maybeDialect.getOrElse(Dialect.current))
+      )
     else if (hasCompilerSupport)
       Configured.error(
         "The Scala compiler option \"-Ywarn-unused\" is required to use OrganizeImports with"
@@ -776,48 +922,6 @@ object OrganizeImports {
     }
   }
 
-  private def prettyPrintImportGroup(group: Seq[Importer]): String =
-    group
-      .map(i => "import " + importerSyntax(i))
-      .mkString("\n")
-
-  /**
-   * HACK: The Scalafix pretty-printer decides to add spaces after open and
-   * before close braces in imports with multiple importees, i.e., `import a.{
-   * b, c }` instead of `import a.{b, c}`. On the other hand, renames are
-   * pretty-printed without the extra spaces, e.g., `import a.{b => c}`. This
-   * behavior is not customizable and makes ordering imports by ASCII order
-   * complicated.
-   *
-   * This function removes the unwanted spaces as a workaround. In cases where
-   * users do want the inserted spaces, Scalafmt should be used after running
-   * the `OrganizeImports` rule.
-   */
-  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
-
-      case Position.None =>
-        // Position not found, implies that `importer` is derived from certain existing import
-        // statement(s). Pretty-prints it.
-        val syntax = importer.syntax
-
-        // NOTE: We need to check whether the input importer is curly braced first and then replace
-        // the first "{ " and the last " }" if any. Naive string replacement is insufficient, e.g.,
-        // a quoted-identifier like "`{ d }`" may cause broken output.
-        (importer.isCurlyBraced, syntax lastIndexOfSlice " }") match {
-          case (_, -1) =>
-            syntax
-          case (true, index) =>
-            syntax.patch(index, "}", 2).replaceFirst("\\{ ", "{")
-          case _ =>
-            syntax
-        }
-    }
-
   @tailrec private def topQualifierOf(term: Term): Term.Name =
     term match {
       case Term.Select(qualifier, _) => topQualifierOf(qualifier)
@@ -908,11 +1012,11 @@ object OrganizeImports {
    * Categorizes a list of `Importee`s into the following four groups:
    *
    *   - Names, e.g., `Seq`, `Option`, etc.
-   *   - Renames, e.g., `{Long => JLong}`, `{Duration => D}`, etc.
-   *   - Unimports, e.g., `{Foo => _}`.
+   *   - Renames, e.g., `{Long => JLong}`, `Duration as D`, etc.
+   *   - Unimports, e.g., `{Foo => _}` or `Foo as _`.
    *   - Givens, e.g., `{given Foo}`.
    *   - GivenAll, i.e., `given`.
-   *   - Wildcard, i.e., `_`.
+   *   - Wildcard, i.e., `_` or `*`.
    */
   object Importees {
     def unapply(importees: Seq[Importee]): Option[
@@ -967,40 +1071,4 @@ object OrganizeImports {
     def infoNoThrow(implicit doc: SemanticDocument): Option[SymbolInformation] =
       Try(symbol.info).toOption.flatten
   }
-
-  implicit private class ImporterExtension(importer: Importer) {
-
-    /** Checks whether the `Importer` is curly-braced when pretty-printed. */
-    def isCurlyBraced: Boolean = {
-      val importees @ Importees(_, renames, unimports, _, _, _) =
-        importer.importees
-      renames.nonEmpty || unimports.nonEmpty || importees.length > 1
-    }
-
-    /**
-     * Returns an `Importer` with all the `Importee`s that are selected from the
-     * input `Importer` and satisfy a predicate. If all the `Importee`s are
-     * selected, the input `Importer` instance is returned to preserve the
-     * original source level formatting. If none of the `Importee`s are
-     * selected, returns a `None`.
-     */
-    def filterImportees(f: Importee => Boolean): Option[Importer] = {
-      val filtered = importer.importees filter f
-      if (filtered.length == importer.importees.length) Some(importer)
-      else if (filtered.isEmpty) None
-      else Some(importer.copy(importees = filtered))
-    }
-
-    /** Returns true if the `Importer` contains a standalone wildcard. */
-    def hasWildcard: Boolean = {
-      val Importees(_, _, unimports, _, _, wildcard) = importer.importees
-      unimports.isEmpty && wildcard.nonEmpty
-    }
-
-    /** Returns true if the `Importer` contains a standalone given wildcard. */
-    def hasGivenAll: Boolean = {
-      val Importees(_, _, unimports, _, givenAll, _) = importer.importees
-      unimports.isEmpty && givenAll.nonEmpty
-    }
-  }
 }

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

@@ -5,14 +5,14 @@ OrganizeImports.groupedImports = Merge
  */
 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/test/organizeImports/CurlyBracedSingleImportee.scala

@@ -5,6 +5,7 @@ OrganizeImports.removeUnused = false
 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/ExplodeImportsFormatPreserving.scala

@@ -7,6 +7,6 @@ OrganizeImports.groupedImports = Explode
 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/ImportsOrderSymbolsFirst.scala

@@ -15,6 +15,9 @@ 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/output/src/main/scala/test/organizeImports/CurlyBracedSingleImportee.scala → scalafix-tests/output/src/main/scala-2/test/organizeImports/CurlyBracedSingleImportee.scala

@@ -1,6 +1,7 @@
 package test.organizeImports
 
 import scala.collection.Map
+import scala.collection.{Seq => _}
 import scala.collection.{Set => ImmutableSet}
 
 object CurlyBracedSingleImportee

scalafix-tests/output/src/main/scala/test/organizeImports/ImportsOrderSymbolsFirst.scala → scalafix-tests/output/src/main/scala-2/test/organizeImports/ImportsOrderSymbolsFirst.scala

@@ -1,7 +1,10 @@
 package test.organizeImports
 
 import test.organizeImports.QuotedIdent._
+import test.organizeImports.QuotedIdent.{`a.b` => ab}
+import test.organizeImports.QuotedIdent.`a.b`
 import test.organizeImports.QuotedIdent.`a.b`.{c => _, _}
+import test.organizeImports.QuotedIdent.`a.b`.`{ d }`.{  e => E  }
 import test.organizeImports.QuotedIdent.`a.b`.`{ d }`.e
 
 import scala.concurrent._

scalafix-tests/output/src/main/scala-3/test/organizeImports/CoalesceImportees.scala

@@ -0,0 +1,8 @@
+package test.organizeImports
+
+import scala.collection.immutable.{Map, Seq, Vector}
+import scala.collection.mutable.*
+import scala.concurrent.{Channel as Ch, *}
+import scala.util.{Random as _, *}
+
+object CoalesceImportees

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

@@ -1,6 +1,6 @@
 package test.organizeImports
 
-import test.organizeImports.Givens._
-import test.organizeImports.Givens.{B => B1, C => _, _, given}
+import test.organizeImports.Givens.*
+import test.organizeImports.Givens.{B as B1, C as _, *, given}
 
 object CoalesceImporteesGivensAndNames