Add rudimentary ExplicitImplicit semantic rewrite.

- Use (super experimental) 2.0 version of scalameta
- Use (super experimental) 4.0 version of scala.meta paradise
- SBT plugin injects the 4.0 paradise compiler plugin and compiles with -Dpersist.enable
- ExplicitImplicit inserts the fully qualified type name, no fancy imports yet
- Everything is tested, including the SBT plugin interaction!
- Fixed tiny bug in VolatileLazyVal because I couldn't help myself

.scalafmt.conf

@@ -0,0 +1,6 @@
+assumeStandardLibraryStripMargin = true
+align.tokens = [
+  { code = "%", owner = "Infix" }
+  { code = "%%", owner = "Infix" }
+  { code = "%%%", owner = "Infix" }
+]

README.md

@@ -1,4 +1,4 @@
-# scalafix [![codecov.io](https://codecov.io/github/scalacenter/scalafix/coverage.svg?branch=master)](https://codecov.io/github/scalacenter/scalafix?branch=master) [![Build Status](http://stats.lassie.io:8001/api/badges/scalacenter/scalafix/status.svg)](http://stats.lassie.io:8001/scalacenter/scalafix) [![Join the chat at https://gitter.im/scalacenter/scalafix](https://badges.gitter.im/scalacenter/scalafix.svg)](https://gitter.im/scalacenter/scalafix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# scalafix [![Build Status](http://stats.lassie.io:8001/api/badges/scalacenter/scalafix/status.svg)](http://stats.lassie.io:8001/scalacenter/scalafix) [![Join the chat at https://gitter.im/scalacenter/scalafix](https://badges.gitter.im/scalacenter/scalafix.svg)](https://gitter.im/scalacenter/scalafix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 The [first meeting of the Scala Center advisory board](http://scala-lang.org/blog/2016/05/30/scala-center-advisory-board.html#the-first-meeting)
 approved a proposal to define a migration path from Scala 2.x to Dotty.

bin/nailgun_integration_test.sh

@@ -2,6 +2,7 @@
 set -e
 
 echo "Running nailgun integration test..."
+ng ng-stop || true
 
 cwd=$(pwd)
 cd cli/target/pack

bin/testAll.sh

@@ -1,9 +1,12 @@
 #!/bin/bash
 set -e
 
-sbt clean coverage test
+
+sbt -Dpersist.enable clean semanticCompile/compile
+#sbt coverage test # coverage seems to break the semantic tests :/
+sbt test
 sbt "; publishLocal ; scripted ; cli/pack"
-sbt coverageAggregate
+#sbt coverageAggregate
 
 # Integration tests
 ./bin/nailgun_integration_test.sh

build.sbt

@@ -3,13 +3,14 @@ import sbt.ScriptedPlugin._
 import scoverage.ScoverageSbtPlugin.ScoverageKeys._
 
 scalafmtConfig in ThisBuild := Some(file(".scalafmt"))
+val Versions = _root_.scalafix.Versions
 
 lazy val buildSettings = Seq(
   organization := "ch.epfl.scala",
   assemblyJarName in assembly := "scalafix.jar",
   // See core/src/main/scala/ch/epfl/scala/Versions.scala
-  version := scalafix.Versions.nightly,
-  scalaVersion := scalafix.Versions.scala,
+  version := Versions.nightly,
+  scalaVersion := Versions.scala,
   updateOptions := updateOptions.value.withCachedResolution(true)
 )
 
@@ -97,6 +98,7 @@ lazy val root = project
     core,
     cli,
     readme,
+    semanticCompile,
     sbtScalafix
   )
   .dependsOn(core)
@@ -105,11 +107,12 @@ lazy val core = project
   .settings(allSettings)
   .settings(
     moduleName := "scalafix-core",
+    fork := true,
     addCompilerPlugin(
       "org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full),
     libraryDependencies ++= Seq(
       "com.lihaoyi"    %% "sourcecode"   % "0.1.2",
-      "org.scalameta"  %% "scalameta"    % "1.0.0",
+      "com.geirsson"   %% "scalameta"    % "2.0.0-M7",
       "org.scala-lang" % "scala-reflect" % scalaVersion.value,
       // Test dependencies
       "org.scalatest"                  %% "scalatest" % "3.0.0" % "test",
@@ -159,6 +162,13 @@ lazy val sbtScalafix = project
     scriptedBufferLog := false
   )
 
+lazy val semanticCompile = project
+    .settings(
+      allSettings,
+      addCompilerPlugin(Versions.paradiseOrg % "paradise_2.11.8" % Versions.paradiseVersion),
+      scalacOptions += "-Ybackend:GenBCode"
+    )
+
 lazy val readme = scalatex
   .ScalatexReadme(projectId = "readme",
                   wd = file(""),

cli/src/main/scala/scalafix/cli/Cli.scala

@@ -3,7 +3,6 @@ package scalafix.cli
 import scala.collection.GenSeq
 import scalafix.Failure
 import scalafix.Scalafix
-import scalafix.ScalafixConfig
 import scalafix.rewrite.Rewrite
 import scalafix.util.FileOps
 
@@ -14,6 +13,8 @@ import java.io.PrintStream
 import java.util.concurrent.atomic.AtomicInteger
 import ArgParserImplicits._
 import scala.util.control.NonFatal
+import scalafix.config.ProjectFiles
+import scalafix.config.ScalafixConfig
 
 import caseapp._
 import caseapp.core.Messages
@@ -35,7 +36,10 @@ case class ScalafixOptions(
     ) rewrites: List[Rewrite] = Rewrite.default.toList,
     @Hidden @HelpMessage(
       "Files to fix. Runs on all *.scala files if given a directory."
-    ) @ExtraName("f") files: List[String] = List.empty[String],
+    ) @ExtraName("f") files: List[String] = Nil,
+    @HelpMessage(
+      "Target directory with .class files that contain TASTY fields"
+    ) @ExtraName("f") target: List[String] = Nil,
     @HelpMessage(
       "If true, writes changes to files instead of printing to stdout."
     ) @ExtraName("i") inPlace: Boolean = false,
@@ -47,7 +51,12 @@ case class ScalafixOptions(
     ) debug: Boolean = false,
     @Recurse common: CommonOptions = CommonOptions()
 ) extends App {
-
+  def toConfig = ScalafixConfig(
+    rewrites = rewrites,
+    project = ProjectFiles(
+      targetFiles = target.map(new File(_))
+    )
+  )
   Cli.runOn(this)
 }
 
@@ -56,43 +65,48 @@ object Cli extends AppOf[ScalafixOptions] {
 
   val default = ScalafixOptions()
 
-  def safeHandleFile(file: File, config: ScalafixOptions): Unit = {
-    try handleFile(file, config) catch {
+  def safeHandleFile(file: File,
+                     options: ScalafixOptions,
+                     config: ScalafixConfig): Unit = {
+    try handleFile(file, options, config)
+    catch {
       case NonFatal(e) =>
-        config.common.err.println(
-          s"""Unexpected error fixing file: $file
-             |Cause: $e""".stripMargin)
+        options.common.err.println(s"""Unexpected error fixing file: $file
+                                      |Cause: $e""".stripMargin)
     }
   }
-  def handleFile(file: File, config: ScalafixOptions): Unit = {
-    Scalafix
-      .fix(FileOps.readFile(file), ScalafixConfig(config.rewrites)) match {
+  def handleFile(file: File,
+                 options: ScalafixOptions,
+                 config: ScalafixConfig): Unit = {
+    val fixed = Scalafix.fix(FileOps.readFile(file), options.toConfig)
+    fixed match {
       case Right(code) =>
-        if (config.inPlace) {
+        if (options.inPlace) {
           FileOps.writeFile(file, code)
-        } else config.common.out.write(code.getBytes)
+        } else options.common.out.write(code.getBytes)
       case Left(e: Failure.ParseError) =>
-        if (config.files.contains(file.getPath)) {
+        if (options.files.contains(file.getPath)) {
           // Only log if user explicitly specified that file.
-          config.common.err.write(e.toString.getBytes())
+          options.common.err.write(e.toString.getBytes())
         }
       case Left(e) =>
-        config.common.err.write(s"Failed to fix $file. Cause: $e".getBytes)
+        options.common.err.write(s"Failed to fix $file. Cause: $e".getBytes)
     }
   }
 
-  def runOn(config: ScalafixOptions): Unit = {
-    config.files.foreach { pathStr =>
+  def runOn(options: ScalafixOptions): Unit = {
+    val config = options.toConfig
+    options.files.foreach { pathStr =>
       val path = new File(pathStr)
-      val workingDirectory = new File(config.common.workingDirectory)
+      val workingDirectory = new File(options.common.workingDirectory)
       val realPath: File =
         if (path.isAbsolute) path
-        else new File(config.common.workingDirectory, path.getPath)
+        else new File(options.common.workingDirectory, path.getPath)
       if (realPath.isDirectory) {
         val filesToFix: GenSeq[String] = {
           val files =
             FileOps.listFiles(realPath).filter(x => x.endsWith(".scala"))
-          if (config.parallel) files.par
+          if (options.parallel) files.par
           else files
         }
         val logger = new TermDisplay(new OutputStreamWriter(System.out))
@@ -102,13 +116,13 @@ object Cli extends AppOf[ScalafixOptions] {
         logger.taskLength(msg, filesToFix.length, 0)
         val counter = new AtomicInteger()
         filesToFix.foreach { x =>
-          safeHandleFile(new File(x), config)
+          safeHandleFile(new File(x), options, config)
           val progress = counter.incrementAndGet()
           logger.taskProgress(msg, progress)
         }
         logger.stop()
       } else {
-        safeHandleFile(realPath, config)
+        safeHandleFile(realPath, options, config)
       }
     }
   }

core/src/main/scala/scala/meta/Mirror.scala

@@ -0,0 +1,11 @@
+package scala.meta
+
+object Mirror {
+  def apply(artifacts: Artifact*)(implicit resolver: Resolver): Mirror = {
+    new Mirror {
+      lazy val domain = Domain(artifacts: _*)(resolver)
+      override def toString =
+        s"""Context(${artifacts.mkString(", ")})($resolver)"""
+    }
+  }
+}

core/src/main/scala/scalafix/Scalafix.scala

@@ -2,6 +2,7 @@ package scalafix
 
 import scala.meta._
 import scala.meta.inputs.Input
+import scalafix.config.ScalafixConfig
 import scalafix.rewrite.RewriteCtx
 import scalafix.util.Patch
 import scalafix.util.TokenList
@@ -14,7 +15,13 @@ object Scalafix {
   def fix(code: Input, config: ScalafixConfig): Fixed = {
     config.parser.apply(code, config.dialect) match {
       case Parsed.Success(ast) =>
-        val ctx = RewriteCtx(config, new TokenList(ast.tokens))
+        val m = Mirror(
+          config.project.targetFiles.map(x => Artifact(x.getAbsolutePath)): _*)
+        val ctx = RewriteCtx(
+          config,
+          new TokenList(ast.tokens),
+          Some(m)
+        )
         val patches: Seq[Patch] = config.rewrites.flatMap(_.rewrite(ast, ctx))
         Right(Patch.apply(ast.tokens, patches))
       case Parsed.Error(pos, msg, e) =>

core/src/main/scala/scalafix/Versions.scala

@@ -1,7 +1,9 @@
 package scalafix
 
 object Versions {
-  val nightly = "0.1.0"
+  val nightly = "0.1.0-SNAPSHOT"
   val stable = nightly
   val scala = "2.11.8"
+  val paradiseVersion = "4.0.0-M3"
+  val paradiseOrg = "com.geirsson"
 }

core/src/main/scala/scalafix/config/ProjectFiles.scala

@@ -0,0 +1,8 @@
+package scalafix.config
+
+import java.io.File
+
+case class ProjectFiles(
+    targetFiles: Seq[File] = Nil,
+    files: Seq[File] = Nil
+)

core/src/main/scala/scalafix/ScalafixConfig.scala → core/src/main/scala/scalafix/config/ScalafixConfig.scala

@@ -1,13 +1,16 @@
-package scalafix
+package scalafix.config
 
 import scala.meta.Dialect
 import scala.meta.Tree
 import scala.meta.dialects.Scala211
 import scala.meta.parsers.Parse
 import scalafix.rewrite.Rewrite
 
+import java.io.File
+
 case class ScalafixConfig(
     rewrites: Seq[Rewrite] = Rewrite.default,
     parser: Parse[_ <: Tree] = Parse.parseSource,
-    dialect: Dialect = Scala211
+    dialect: Dialect = Scala211,
+    project: ProjectFiles = ProjectFiles()
 )

core/src/main/scala/scalafix/rewrite/ExplicitImplicit.scala

@@ -0,0 +1,29 @@
+package scalafix.rewrite
+
+import scala.meta._
+import scala.meta.internal.prettyprinters.Attributes
+import scala.meta.tokens.Token.Comment
+import scala.meta.tokens.Token.LeftBrace
+import scala.meta.tokens.Token.RightBrace
+import scala.meta.tokens.Token.RightParen
+import scala.meta.tokens.Token.Space
+import scalafix.util.Patch
+import scalafix.util.SemanticOracle
+import scalafix.util.logger
+
+case object ExplicitImplicit extends Rewrite {
+
+  override def rewrite(ast: Tree, ctx: RewriteCtx): Seq[Patch] = {
+    val builder = Seq.newBuilder[Patch]
+    val oracle = new SemanticOracle(ctx.mirror.get)
+    ast.collect {
+      case Defn.Val(mods, Seq(Pat.Var.Term(t: Term.Name)), decltpe, _)
+          if decltpe.isEmpty && mods.exists(_.syntax == "implicit") =>
+        oracle.getType(t).foreach { typ =>
+          val toks = t.tokens
+          builder += Patch(toks.head, toks.last, s"${t.syntax}: $typ")
+        }
+    }
+    builder.result()
+  }
+}

core/src/main/scala/scalafix/rewrite/Rewrite.scala

@@ -4,9 +4,7 @@ import scala.meta._
 import scalafix.util.Patch
 
 abstract class Rewrite {
-
   def rewrite(code: Tree, rewriteCtx: RewriteCtx): Seq[Patch]
-
 }
 
 object Rewrite {
@@ -15,6 +13,7 @@ object Rewrite {
   }
 
   val name2rewrite: Map[String, Rewrite] = nameMap[Rewrite](
+    ExplicitImplicit,
     ProcedureSyntax,
     VolatileLazyVal
   )

core/src/main/scala/scalafix/rewrite/RewriteCtx.scala

@@ -1,9 +1,18 @@
 package scalafix.rewrite
 
-import scalafix.ScalafixConfig
+import scala.meta.Tree
+import scala.meta.inputs.Input
+import scala.meta.semantic.Mirror
+import scalafix.config.ScalafixConfig
 import scalafix.util.TokenList
 
+case class RewriteInput(
+    input: Input,
+    ast: Tree
+)
+
 case class RewriteCtx(
     config: ScalafixConfig,
-    tokenList: TokenList
+    tokenList: TokenList,
+    mirror: Option[Mirror]
 )

core/src/main/scala/scalafix/rewrite/VolatileLazyVal.scala

@@ -10,13 +10,13 @@ case object VolatileLazyVal extends Rewrite {
         case x if x.syntax == "@volatile" =>
           None
         case x if x.syntax == "lazy" =>
-          Some(x.tokens.head)
+          Some(defn.mods.head.tokens.head)
       }
     }.flatten
   }
   override def rewrite(ast: Tree, ctx: RewriteCtx): Seq[Patch] = {
     ast.collect {
-      case NonVolatileLazyVal(tok) => Patch(tok, tok, "@volatile lazy")
+      case NonVolatileLazyVal(tok) => Patch(tok, tok, s"@volatile ${tok.syntax}")
     }
   }
 }