Allow configuring the dialect in Scalafix

.github/workflows/ci.yml

@@ -15,6 +15,7 @@ jobs:
           - "ci-211"
           - "ci-212"
           - "ci-213"
+          - "ci-3"
     steps:
       - uses: actions/checkout@v2
       - uses: olafurpg/setup-scala@v10

build.sbt

@@ -1,14 +1,15 @@
 import Dependencies._
+import sbt.Keys.scalacOptions
 
 inThisBuild(
   List(
     onLoadMessage := s"Welcome to scalafix ${version.value}",
     scalaVersion := scala213,
     crossScalaVersions := List(scala213, scala212, scala211),
     fork := true,
+    scalacOptions ++= List("-P:semanticdb:synthetics:on"),
     semanticdbEnabled := true,
     semanticdbVersion := scalametaV,
-    scalacOptions ++= List("-P:semanticdb:synthetics:on"),
     scalafixScalaBinaryVersion := scalaBinaryVersion.value,
     scalafixDependencies += "com.github.liancheng" %% "organize-imports" % "0.5.0"
   )
@@ -128,14 +129,19 @@ lazy val testsInput = project
   .in(file("scalafix-tests/input"))
   .settings(
     noPublishAndNoMima,
+    crossScalaVersions := List(scala3, scala213, scala212, scala211),
+    scalacOptions --= (if (isScala3.value)
+                         Seq("-P:semanticdb:synthetics:on")
+                       else Nil),
     scalacOptions ~= (_.filterNot(_ == "-Yno-adapted-args")),
     scalacOptions += warnAdaptedArgs.value, // For NoAutoTupling
     scalacOptions += warnUnusedImports.value, // For RemoveUnused
     scalacOptions += "-Ywarn-unused", // For RemoveUnusedTerms
     scalacOptions ++= maxwarns.value, // Increase the maximum warnings to print
     logLevel := Level.Error, // avoid flood of compiler warnings
-    libraryDependencies ++= testsDeps,
-    libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value,
+    libraryDependencies ++= (if (isScala2.value)
+                               testsDeps :+ "org.scala-lang" % "scala-reflect" % scalaVersion.value
+                             else Nil),
     coverageEnabled := false
   )
   .disablePlugins(ScalafixPlugin)
@@ -144,9 +150,13 @@ lazy val testsOutput = project
   .in(file("scalafix-tests/output"))
   .settings(
     noPublishAndNoMima,
+    scalacOptions --= (if (scalaVersion.value.startsWith("3"))
+                         Seq("-P:semanticdb:synthetics:on")
+                       else Nil),
     scalacOptions -= warnUnusedImports.value,
-    libraryDependencies ++= testsDeps,
-    libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value,
+    libraryDependencies ++= (if (scalaVersion.value.startsWith("2"))
+                               testsDeps :+ "org.scala-lang" % "scala-reflect" % scalaVersion.value
+                             else Nil),
     coverageEnabled := false
   )
   .disablePlugins(ScalafixPlugin)

project/Dependencies.scala

@@ -7,6 +7,7 @@ object Dependencies {
   val scala211 = "2.11.12"
   val scala212 = "2.12.13"
   val scala213 = "2.13.5"
+  val scala3 = "3.0.0-RC3"
   // we support 3 last binary versions of scala212 and scala213
   val testedPreviousScalaVersions: Map[String, List[String]] =
     List(scala213, scala212).map(version => version -> previousVersions(version)).toMap

project/Mima.scala

@@ -20,7 +20,9 @@ object Mima {
       ProblemFilters.exclude[ReversedMissingMethodProblem]("scalafix.interfaces.ScalafixFileEvaluation.getError"),
       ProblemFilters.exclude[DirectMissingMethodProblem]("scalafix.v1.SemanticDocument.fromPath"),
       ProblemFilters.exclude[Problem]("scala.meta.internal.*"),
-      ProblemFilters.exclude[Problem]("scala.tools.nsc.interactive.*")
+      ProblemFilters.exclude[Problem]("scala.tools.nsc.interactive.*"),
+      ProblemFilters.exclude[Problem]("scalafix.syntax.package.XtensionDocument"),
+      ProblemFilters.exclude[MissingClassProblem]("scalafix.syntax.package$XtensionDocument")
     )
   }
 }

project/ScalafixBuild.scala

@@ -29,6 +29,12 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
     lazy val isFullCrossVersion = Seq(
       crossVersion := CrossVersion.full
     )
+    lazy val isScala3 = Def.setting {
+      scalaVersion.value.startsWith("3")
+    }
+    lazy val isScala2 = Def.setting {
+      scalaVersion.value.startsWith("2")
+    }
     lazy val isScala213 = Def.setting {
       scalaVersion.value.startsWith("2.13")
     }
@@ -108,6 +114,11 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
       "unit/test:runMain scalafix.tests.util.SaveExpect" ::
         s
     },
+    commands += Command.command("ci-3") { s =>
+      s"""set testsInput/scalaVersion := "$scala3"""" ::
+        s"""set testsOutput/scalaVersion := "$scala3"""" ::
+        "unit/testOnly scalafix.tests.rule.RuleSuite" :: s
+    },
     commands += Command.command("ci-213") { s =>
       s"""set ThisBuild/scalaVersion := "$scala213"""" ::
         "unit/test" ::

scalafix-cli/src/main/scala/scalafix/internal/v1/Args.scala

@@ -17,6 +17,7 @@ import scala.util.Failure
 import scala.util.Success
 import scala.util.Try
 
+import scala.meta.Dialect
 import scala.meta.internal.io.PathIO
 import scala.meta.internal.symtab.SymbolTable
 import scala.meta.io.AbsolutePath
@@ -33,6 +34,7 @@ import scalafix.interfaces.ScalafixMainCallback
 import scalafix.internal.config.FilterMatcher
 import scalafix.internal.config.PrintStreamReporter
 import scalafix.internal.config.ScalafixConfig
+import scalafix.internal.config.ScalafixMetaconfigReaders
 import scalafix.internal.diff.DiffDisable
 import scalafix.internal.interfaces.MainCallbackImpl
 import scalafix.internal.jgit.JGitDiff
@@ -54,6 +56,11 @@ case class Args(
     @ExtraName("remainingArgs")
     @ExtraName("f")
     files: List[AbsolutePath] = Nil,
+    @Description(
+      "default Scala2" +
+        "Possibilities: Scala2, Scala3"
+    )
+    dialect: Option[Dialect] = None,
     @Description(
       "File path to a .scalafix.conf configuration file. " +
         "Defaults to .scalafix.conf in the current working directory, if any."
@@ -214,6 +221,16 @@ case class Args(
     }
   }
 
+  def configureDialect(
+      scalafixConfig: ScalafixConfig
+  ): Configured[ScalafixConfig] = {
+    dialect match {
+      case Some(value) =>
+        Configured.ok(scalafixConfig.copy(dialect = value))
+      case None => Configured.ok(scalafixConfig)
+    }
+  }
+
   def fileConfig: Configured[Conf] = {
     val toRead: Option[AbsolutePath] = config.orElse {
       val defaultPath = cwd.resolve(".scalafix.conf")
@@ -377,20 +394,25 @@ case class Args(
           configuredSymtab |@|
           configuredRules(base, scalafixConfig) |@|
           resolvedPathReplace |@|
-          configuredDiffDisable
-      ).map { case ((((root, symtab), rulez), pathReplace), diffDisable) =>
-        ValidatedArgs(
-          this,
-          symtab,
-          rulez,
-          scalafixConfig,
-          classLoader,
-          root,
-          pathReplace,
-          diffDisable,
-          delegator,
-          semanticdbFilterMatcher
-        )
+          configuredDiffDisable |@|
+          configureDialect(scalafixConfig)
+      ).map {
+        case (
+              ((((root, symtab), rulez), pathReplace), diffDisable),
+              scalafixConfig
+            ) =>
+          ValidatedArgs(
+            this,
+            symtab,
+            rulez,
+            scalafixConfig,
+            classLoader,
+            root,
+            pathReplace,
+            diffDisable,
+            delegator,
+            semanticdbFilterMatcher
+          )
       }
     }
   }
@@ -430,6 +452,12 @@ object Args {
     ConfDecoder.stringConfDecoder.map(glob =>
       FileSystems.getDefault.getPathMatcher("glob:" + glob)
     )
+  implicit val dialectDecoder: ConfDecoder[Dialect] =
+    ScalafixMetaconfigReaders.dialectReader
+  implicit val dialectEncoder: ConfEncoder[Dialect] =
+    ConfEncoder.StringEncoder.contramap(_.toString)
+  implicit val dialectPrint: TPrint[Dialect] =
+    TPrint.make[Dialect](_ => "dialect")
   implicit val callbackDecoder: ConfDecoder[ScalafixMainCallback] =
     ConfDecoder.stringConfDecoder.map(_ => MainCallbackImpl.default)
 
@@ -457,6 +485,7 @@ object Args {
     TPrint.make[PathMatcher](_ => "<glob>")
   implicit val confPrint: TPrint[Conf] =
     TPrint.make[Conf](implicit cfg => TPrint.implicitly[ScalafixConfig].render)
+
   implicit def optionPrint[T](implicit
       ev: pprint.TPrint[T]
   ): TPrint[Option[T]] =

scalafix-cli/src/main/scala/scalafix/internal/v1/MainOps.scala

@@ -18,7 +18,6 @@ import scala.util.Try
 import scala.util.control.NoStackTrace
 import scala.util.control.NonFatal
 
-import scala.meta.Tree
 import scala.meta.inputs.Input
 import scala.meta.internal.semanticdb.TextDocument
 import scala.meta.io.AbsolutePath
@@ -293,10 +292,7 @@ object MainOps {
       input: Input,
       file: AbsolutePath
   ): PatchInternals.ResultWithContext = {
-    val tree = LazyValue.later { () =>
-      args.parse(input).get: Tree
-    }
-    val doc = SyntacticDocument(input, tree, args.diffDisable, args.config)
+    val doc = SyntacticDocument(input, args.diffDisable, args.config)
     if (args.rules.isSemantic) {
       val relpath = file.toRelative(args.sourceroot)
       val sdoc = SemanticDocument.fromPath(

scalafix-cli/src/main/scala/scalafix/internal/v1/ValidatedArgs.scala

@@ -30,7 +30,7 @@ case class ValidatedArgs(
 
   def parse(input: Input): Parsed[Source] = {
     import scala.meta._
-    val dialect = config.parser.dialectForFile(input.syntax)
+    val dialect = config.dialectForFile(input.syntax)
     dialect(input).parse[Source]
   }
 

scalafix-core/src/main/scala/scala/meta/internal/scalafix/ScalafixScalametaHacks.scala

@@ -1,16 +1,10 @@
 package scala.meta.internal.scalafix
 
-import scala.meta.Dialect
 import scala.meta.Tree
-import scala.meta.dialects
 import scala.meta.internal.semanticdb.Scala.Names
 import scala.meta.internal.trees.Origin
 
 object ScalafixScalametaHacks {
-  def dialect(language: String): Dialect =
-    if (language == "Scala") dialects.Scala212
-    else if (language.isEmpty) dialects.Scala212
-    else Dialect.standards(language)
   def resetOrigin(tree: Tree): Tree = tree.withOrigin(Origin.None)
   def encode(name: String): String = Names.encode(name)
 }

scalafix-core/src/main/scala/scalafix/internal/config/ParserConfig.scala

@@ -1,37 +1 @@
-package scalafix.internal.config
 
-import java.nio.file.FileSystems
-import java.nio.file.PathMatcher
-
-import scala.meta.Dialect
-
-import metaconfig._
-
-case class ParserConfig(
-    literalTypes: Boolean = true,
-    trailingCommas: Boolean = true,
-    inlineKeyword: Boolean = false
-) {
-
-  private val dialect = scala.meta.dialects.Scala213.copy(
-    allowLiteralTypes = literalTypes,
-    allowTrailingCommas = trailingCommas,
-    allowInlineMods = inlineKeyword,
-    allowInlineIdents = !inlineKeyword
-  )
-  private val sbtDialect = dialect.copy(allowToplevelTerms = true)
-
-  def dialectForFile(path: String): Dialect =
-    if (path.endsWith(".sbt")) sbtDialect
-    else dialect
-
-}
-
-object ParserConfig {
-  val sbtMatcher: PathMatcher =
-    FileSystems.getDefault.getPathMatcher("glob:*.sbt")
-  implicit val surface: generic.Surface[ParserConfig] =
-    generic.deriveSurface
-  implicit val codec: ConfCodec[ParserConfig] =
-    generic.deriveCodec(ParserConfig())
-}

scalafix-core/src/main/scala/scalafix/internal/config/ScalafixConfig.scala

@@ -1,27 +1,29 @@
 package scalafix.internal.config
 
 import scala.meta._
-import scala.meta.dialects.Scala212
 
 import metaconfig._
 import metaconfig.generic.Surface
 import scalafix.Versions
+import scalafix.internal.config.ScalafixConfig._
 
 case class ScalafixConfig(
     version: String = Versions.version,
-    parser: ParserConfig = ParserConfig(),
     debug: DebugConfig = DebugConfig(),
     groupImportsByPrefix: Boolean = true,
     fatalWarnings: Boolean = true,
     reporter: ScalafixReporter = ScalafixReporter.default,
     patches: ConfigRulePatches = ConfigRulePatches.default,
-    dialect: Dialect = ScalafixConfig.DefaultDialect,
+    dialect: Dialect = ScalafixConfig.Scala2,
     lint: LintConfig = LintConfig.default
 ) {
 
+  def dialectForFile(path: String): Dialect =
+    if (path.endsWith(".sbt")) DefaultSbtDialect
+    else dialect
+
   val reader: ConfDecoder[ScalafixConfig] =
     ScalafixConfig.decoder(this)
-
 }
 
 object ScalafixConfig {
@@ -34,33 +36,6 @@ object ScalafixConfig {
   implicit lazy val ScalafixConfigDecoder: ConfDecoder[ScalafixConfig] =
     decoder(default)
 
-  val DefaultDialect: Dialect = Scala212.copy(
-    // Are `&` intersection types supported by this dialect?
-    allowAndTypes = true,
-    // Are extractor varargs specified using ats, i.e. is `case Extractor(xs @ _*)` legal or not?
-    allowAtForExtractorVarargs = true,
-    // Are extractor varargs specified using colons, i.e. is `case Extractor(xs: _*)` legal or not?
-    allowColonForExtractorVarargs = true,
-    // Are inline vals and defs supported by this dialect?
-    allowInlineMods = false,
-    // Are literal types allowed, i.e. is `val a : 42 = 42` legal or not?
-    allowLiteralTypes = true,
-    // Are `|` (union types) supported by this dialect?
-    allowOrTypes = true,
-    // Are trailing commas allowed? SIP-27.
-    allowTrailingCommas = true,
-    // Are trait allowed to have parameters?
-    // They are in Dotty, but not in Scala 2.12 or older.
-    allowTraitParameters = true,
-    // Are view bounds supported by this dialect?
-    // Removed in Dotty.
-    allowViewBounds = true,
-    // Are `with` intersection types supported by this dialect?
-    allowWithTypes = true,
-    // Are XML literals supported by this dialect?
-    // We plan to deprecate XML literal syntax, and some dialects
-    // might go ahead and drop support completely.
-    allowXmlLiterals = true
-  )
-
+  val Scala2: Dialect = scala.meta.dialects.Scala213
+  val DefaultSbtDialect: Dialect = scala.meta.dialects.Sbt1
 }