Run -rewrite -source 3.6-migration, enable Scalafix in tests (#4512)

This wipes out the bulk of the annoying warnings that scroll past when
compiling

There are still a few residual warnings, but I'll tackle those in a
follow up

.scalafix.conf

@@ -1,5 +1,4 @@
 rules = [
     RemoveUnused,
     NoAutoTupling
-    ExplicitResultTypes
 ]

bsp/src/mill/bsp/BspWorker.scala

@@ -17,7 +17,7 @@ private trait BspWorker {
 
 private object BspWorker {
 
-  private[this] var worker: Option[BspWorker] = None
+  private var worker: Option[BspWorker] = None
 
   def apply(
       workspace: os.Path,

bsp/worker/src/mill/bsp/worker/BspTestReporter.scala

@@ -65,7 +65,7 @@ private class BspTestReporter(
 
   // Compute the display name of the test / test suite
   // to which the given event relates
-  private[this] def getDisplayName(e: Event): String = {
+  private def getDisplayName(e: Event): String = {
     e.selector() match {
       case s: NestedSuiteSelector => s.suiteId()
       case s: NestedTestSelector => s.suiteId() + "." + s.testName()

bsp/worker/src/mill/bsp/worker/BspWorkerImpl.scala

@@ -56,7 +56,7 @@ private class BspWorkerImpl() extends BspWorker {
       }
 
       val bspServerHandle = new BspServerHandle {
-        private[this] var lastResult0: Option[BspServerResult] = None
+        private var lastResult0: Option[BspServerResult] = None
 
         override def runSession(evaluators: Seq[Evaluator]): BspServerResult = {
           lastResult0 = None

bsp/worker/src/mill/bsp/worker/MillBuildServer.scala

@@ -48,7 +48,7 @@ private class MillBuildServer(
 
   private[worker] var cancellator: Boolean => Unit = shutdownBefore => ()
   private[worker] var onSessionEnd: Option[BspServerResult => Unit] = None
-  protected var client: BuildClient = _
+  protected var client: BuildClient = scala.compiletime.uninitialized
   private var initialized = false
   private var shutdownRequested = false
   protected var clientWantsSemanticDb = false
@@ -57,7 +57,7 @@ private class MillBuildServer(
   /** `true` when client and server support the `JvmCompileClasspathProvider` request. */
   protected var enableJvmCompileClasspathProvider = false
 
-  private[this] var statePromise: Promise[State] = Promise[State]()
+  private var statePromise: Promise[State] = Promise[State]()
 
   def updateEvaluator(evaluatorsOpt: Option[Seq[Evaluator]]): Unit = {
     debug(s"Updating Evaluator: $evaluatorsOpt")
@@ -523,7 +523,7 @@ private class MillBuildServer(
         .foldLeft(StatusCode.OK) { (overallStatusCode, targetId) =>
           state.bspModulesById(targetId) match {
             case (testModule: TestModule, ev) =>
-              val testTask = testModule.testLocal(argsMap(targetId.getUri): _*)
+              val testTask = testModule.testLocal(argsMap(targetId.getUri)*)
 
               // notifying the client that the testing of this build target started
               val taskStartParams = new TaskStartParams(new TaskId(testTask.hashCode().toString))
@@ -601,7 +601,7 @@ private class MillBuildServer(
             }
             val compileTargetName = (module.millModuleSegments ++ Label("compile")).render
             debug(s"about to clean: ${compileTargetName}")
-            val cleanTask = mainModule.clean(ev, Seq(compileTargetName): _*)
+            val cleanTask = mainModule.clean(ev, Seq(compileTargetName)*)
             val cleanResult = evaluate(
               ev,
               Strict.Agg(cleanTask),
@@ -806,7 +806,7 @@ private class MillBuildServer(
 
   private def evaluate(
       evaluator: Evaluator,
-      goals: Agg[Task[_]],
+      goals: Agg[Task[?]],
       reporter: Int => Option[CompileProblemReporter] = _ => Option.empty[CompileProblemReporter],
       testReporter: TestReporter = DummyTestReporter,
       logger: ColorLogger = null

bsp/worker/src/mill/bsp/worker/MillJvmBuildServer.scala

@@ -72,7 +72,7 @@ private trait MillJvmBuildServer extends JvmBuildServer { this: MillBuildServer
             ev,
             state,
             id,
-            _: TestModule with JavaModule,
+            _: (TestModule & JavaModule),
             (
               _,
               forkArgs,

bsp/worker/src/mill/bsp/worker/MillScalaBuildServer.scala

@@ -118,7 +118,7 @@ private trait MillScalaBuildServer extends ScalaBuildServer { this: MillBuildSer
       }
     ) {
       case (ev, state, id, m: TestModule, Some((classpath, testFramework, testClasspath))) =>
-        val (frameworkName, classFingerprint): (String, Agg[(Class[_], Fingerprint)]) =
+        val (frameworkName, classFingerprint): (String, Agg[(Class[?], Fingerprint)]) =
           Jvm.withClassLoader(
             classPath = classpath.map(_.path).toVector,
             sharedPrefixes = Seq("sbt.testing.")
@@ -130,7 +130,7 @@ private trait MillScalaBuildServer extends ScalaBuildServer { this: MillBuildSer
               Agg.from(testClasspath.map(_.path))
             )
             (framework.name(), discoveredTests)
-          }
+          }: @unchecked
         val classes = Seq.from(classFingerprint.map(classF => classF._1.getName.stripSuffix("$")))
         new ScalaTestClassesItem(id, classes.asJava).tap { it =>
           it.setFramework(frameworkName)

bsp/worker/src/mill/bsp/worker/Utils.scala

@@ -106,9 +106,9 @@ private object Utils {
     else Nil
   }
 
-  private[this] def getStatusCodePerTask(
+  private def getStatusCodePerTask(
       results: Evaluator.Results,
-      task: mill.define.Task[_]
+      task: mill.define.Task[?]
   ): StatusCode = {
     results.results(task).result match {
       case Success(_) => StatusCode.OK

build.mill

@@ -472,9 +472,8 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
     else ZincWorkerUtil.scalaBinaryVersion(sv)
   }
 
-  def scalafixConfig = T {
-    if (ZincWorkerUtil.isScala3(scalaVersion())) Some(T.workspace / ".scalafix-3.conf") else None
-  }
+  def scalafixConfig = T { Some(T.workspace / ".scalafix.conf") }
+
   def semanticDbVersion = Deps.semanticDBscala.version
 
   def scaladocOptions = Seq("-Xsource:3")
@@ -492,6 +491,7 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
         // "-Wsafe-init",
         // "-Wnonunit-statement",
         // "-Wimplausible-patterns",
+        // "-rewrite", "-source", "3.6-migration"
       )
       else Seq(
         "-P:acyclic:force",
@@ -524,7 +524,9 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
 
   /** Default tests module. */
   lazy val test: MillScalaTests = new MillScalaTests {}
-  trait MillScalaTests extends ScalaTests with MillJavaModule with MillBaseTestsModule {
+  trait MillScalaTests extends ScalaTests with MillJavaModule with MillBaseTestsModule
+      with ScalafixModule {
+    def scalafixConfig = T { Some(T.workspace / ".scalafix.conf") }
     def forkArgs = super.forkArgs() ++ outer.testArgs()
     def moduleDeps = outer.testModuleDeps
     def ivyDeps = super.ivyDeps() ++ outer.testIvyDeps()

ci/mill-bootstrap.patch

@@ -1,5 +1,5 @@
 diff --git a/build.mill b/build.mill
-index 4f66e7cfeb7..1c608ae4d86 100644
+index 70cfce14468..8ea29a961ab 100644
 --- a/build.mill
 +++ b/build.mill
 @@ -1,9 +1,9 @@
@@ -48,7 +48,16 @@ index 4f66e7cfeb7..1c608ae4d86 100644
    def scalaVersion = Deps.scalaVersion
    def scalapVersion: T[String] = Deps.scala2Version
    def scalafixScalaBinaryVersion = T {
-@@ -561,7 +561,8 @@ trait MillBaseTestsModule extends TestModule {
+@@ -525,7 +525,7 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
+   /** Default tests module. */
+   lazy val test: MillScalaTests = new MillScalaTests {}
+   trait MillScalaTests extends ScalaTests with MillJavaModule with MillBaseTestsModule
+-      with ScalafixModule {
++      /*with ScalafixModule*/ {
+     def scalafixConfig = T { Some(T.workspace / ".scalafix.conf") }
+     def forkArgs = super.forkArgs() ++ outer.testArgs()
+     def moduleDeps = outer.testModuleDeps
+@@ -565,7 +565,8 @@ trait MillBaseTestsModule extends TestModule {
  trait MillPublishScalaModule extends MillScalaModule with MillPublishJavaModule
 
  /** Publishable module which contains strictly handled API. */
@@ -58,7 +67,7 @@ index 4f66e7cfeb7..1c608ae4d86 100644
    import com.github.lolgab.mill.mima._
    override def mimaBinaryIssueFilters: T[Seq[ProblemFilter]] = Seq(
      // (5x) MIMA doesn't properly ignore things which are nested inside other private things
-@@ -691,7 +692,7 @@ trait MillStableScalaModule extends MillPublishScalaModule with Mima {
+@@ -695,7 +696,7 @@ trait MillStableScalaModule extends MillPublishScalaModule with Mima {
    def skipPreviousVersions: T[Seq[String]] = T {
      T.log.info("Skipping mima for previous versions (!!1000s of errors due to Scala 3)")
      mimaPreviousVersions() // T(Seq.empty[String])
@@ -68,7 +77,7 @@ index 4f66e7cfeb7..1c608ae4d86 100644
 
  object bridge extends Cross[BridgeModule](compilerBridgeScalaVersions)
 diff --git a/dist/package.mill b/dist/package.mill
-index 67d3f94c143..98733778894 100644
+index 5b8d77f5180..72f4963ce5f 100644
 --- a/dist/package.mill
 +++ b/dist/package.mill
 @@ -3,7 +3,7 @@ import mill._, scalalib._, publish._
@@ -111,8 +120,28 @@ index 67d3f94c143..98733778894 100644
      ()
    }
 
+diff --git a/mill-build/build.mill b/mill-build/build.mill
+index 957d929826d..112f1aaccb8 100644
+--- a/mill-build/build.mill
++++ b/mill-build/build.mill
+@@ -4,12 +4,12 @@ import mill.scalalib._
+
+ object `package` extends MillBuildRootModule {
+   override def ivyDeps = Agg(
+-    ivy"de.tototec::de.tobiasroeser.mill.vcs.version::0.4.1",
+-    ivy"com.github.lolgab::mill-mima::0.1.1",
++//    ivy"de.tototec::de.tobiasroeser.mill.vcs.version::0.4.1",
++//    ivy"com.github.lolgab::mill-mima::0.1.1",
+     ivy"net.sourceforge.htmlcleaner:htmlcleaner:2.29",
+     // TODO: implement empty version for ivy deps as we do in import parser
+     ivy"com.lihaoyi::mill-contrib-buildinfo:${mill.api.BuildInfo.millVersion}",
+-    ivy"com.goyeau::mill-scalafix::0.5.0",
++//    ivy"com.goyeau::mill-scalafix::0.5.0",
+     ivy"com.lihaoyi::mill-main-graphviz:${mill.api.BuildInfo.millVersion}",
+     // TODO: document, why we have this dependency
+     ivy"org.jsoup:jsoup:1.18.1"
 diff --git a/website/package.mill b/website/package.mill
-index d558389312e..11f8e5c3ce9 100644
+index eb4f1515dee..a49e72e84fe 100644
 --- a/website/package.mill
 +++ b/website/package.mill
 @@ -40,8 +40,8 @@ object `package` extends RootModule {
@@ -164,23 +193,3 @@ index d558389312e..11f8e5c3ce9 100644
        mainArgs = orderedDiagrams.map { case (p, i, src, dest) => s"$src;$dest;svg" }
      )
 
-diff --git a/mill-build/build.mill b/mill-build/build.mill
-index 957d929826d..112f1aaccb8 100644
---- a/mill-build/build.mill
-+++ b/mill-build/build.mill
-@@ -4,12 +4,12 @@ import mill.scalalib._
-
- object `package` extends MillBuildRootModule {
-   override def ivyDeps = Agg(
--    ivy"de.tototec::de.tobiasroeser.mill.vcs.version::0.4.1",
--    ivy"com.github.lolgab::mill-mima::0.1.1",
-+//    ivy"de.tototec::de.tobiasroeser.mill.vcs.version::0.4.1",
-+//    ivy"com.github.lolgab::mill-mima::0.1.1",
-     ivy"net.sourceforge.htmlcleaner:htmlcleaner:2.29",
-     // TODO: implement empty version for ivy deps as we do in import parser
-     ivy"com.lihaoyi::mill-contrib-buildinfo:${mill.api.BuildInfo.millVersion}",
--    ivy"com.goyeau::mill-scalafix::0.5.0",
-+//    ivy"com.goyeau::mill-scalafix::0.5.0",
-     ivy"com.lihaoyi::mill-main-graphviz:${mill.api.BuildInfo.millVersion}",
-     // TODO: document, why we have this dependency
-     ivy"org.jsoup:jsoup:1.18.1"

contrib/artifactory/src/mill/contrib/artifactory/ArtifactoryPublishModule.scala

@@ -73,7 +73,7 @@ object ArtifactoryPublishModule extends ExternalModule {
       connectTimeout,
       Task.log
     ).publishAll(
-      artifacts: _*
+      artifacts*
     )
   }
 

contrib/bintray/src/mill/contrib/bintray/BintrayPublishModule.scala

@@ -80,7 +80,7 @@ object BintrayPublishModule extends ExternalModule {
       connectTimeout,
       Task.log
     ).publishAll(
-      Task.sequence(publishArtifacts.value)(): _*
+      Task.sequence(publishArtifacts.value)()*
     )
   }
 

contrib/buildinfo/test/src/mill/contrib/buildinfo/BuildInfoTests.scala

@@ -116,13 +116,13 @@ object BuildInfoTests extends TestSuite {
       EmptyBuildInfo,
       testModuleSourcesPath / "scala"
     ).scoped { eval =>
-      val Right(_) = eval.apply(EmptyBuildInfo.buildInfoSources)
+      val Right(_) = eval.apply(EmptyBuildInfo.buildInfoSources): @unchecked
       assert(!os.exists(buildInfoSourcePath(eval)))
     }
 
     test("fileGeneration") - UnitTester(BuildInfoComment, testModuleSourcesPath / "scala").scoped {
       eval =>
-        val Right(_) = eval.apply(BuildInfoComment.compile)
+        val Right(_) = eval.apply(BuildInfoComment.compile): @unchecked
 
         // Make sure that the buildinfo Scala file buildinfo is created and buildinfo
         // resource file is *not* created when we compile the Scala code
@@ -145,7 +145,7 @@ object BuildInfoTests extends TestSuite {
         }
 
         // But becomes created once we package the jar for running
-        val Right(_) = eval.apply(BuildInfoComment.jar)
+        val Right(_) = eval.apply(BuildInfoComment.jar): @unchecked
 
         val expectedResource = "mill.contrib.buildinfo.BuildInfo for foo."
 
@@ -158,7 +158,7 @@ object BuildInfoTests extends TestSuite {
       BuildInfoSettings,
       testModuleSourcesPath / "scala"
     ).scoped { eval =>
-      val Right(result) = eval.apply(BuildInfoSettings.buildInfoSources)
+      val Right(result) = eval.apply(BuildInfoSettings.buildInfoSources): @unchecked
       val path = result.value.head.path
 
       assert(os.exists(path / "foo/bar.scala"))
@@ -168,14 +168,14 @@ object BuildInfoTests extends TestSuite {
     }
 
     test("compile") - UnitTester(BuildInfoPlain, testModuleSourcesPath / "scala").scoped { eval =>
-      val Right(_) = eval.apply(BuildInfoPlain.compile)
+      val Right(_) = eval.apply(BuildInfoPlain.compile): @unchecked
       assert(true)
     }
 
     test("run") - UnitTester(BuildInfoPlain, testModuleSourcesPath / "scala").scoped { eval =>
       val runResult = eval.outPath / "hello-mill"
       val Right(_) =
-        eval.apply(BuildInfoPlain.run(Task.Anon(Args(runResult.toString))))
+        eval.apply(BuildInfoPlain.run(Task.Anon(Args(runResult.toString)))): @unchecked
 
       assert(
         os.exists(runResult),
@@ -185,7 +185,7 @@ object BuildInfoTests extends TestSuite {
 
     test("scalajs") - UnitTester(BuildInfoScalaJS, testModuleSourcesPath / "scala-simple").scoped {
       eval =>
-        val runResult = eval.outPath / "hello-mill"
+        eval.outPath / "hello-mill"
         assert(eval.apply(BuildInfoScalaJS.fastLinkJS).isRight)
     }
 
@@ -195,7 +195,7 @@ object BuildInfoTests extends TestSuite {
       val runResult = eval.outPath / "hello-mill"
 
       val Right(_) =
-        eval.apply(BuildInfoStatic.run(Task.Anon(Args(runResult.toString))))
+        eval.apply(BuildInfoStatic.run(Task.Anon(Args(runResult.toString)))): @unchecked
 
       assert(os.exists(buildInfoSourcePath(eval)))
       assert(!os.exists(buildInfoResourcePath(eval)))
@@ -206,7 +206,7 @@ object BuildInfoTests extends TestSuite {
     test("java") - UnitTester(BuildInfoJava, testModuleSourcesPath / "java").scoped { eval =>
       val runResult = eval.outPath / "hello-mill"
       val Right(_) =
-        eval.apply(BuildInfoJava.run(Task.Anon(Args(runResult.toString))))
+        eval.apply(BuildInfoJava.run(Task.Anon(Args(runResult.toString)))): @unchecked
 
       assert(
         os.exists(runResult),
@@ -219,7 +219,7 @@ object BuildInfoTests extends TestSuite {
         val runResult = eval.outPath / "hello-mill"
         val generatedSrc = eval.outPath / "buildInfoSources.dest/foo/BuildInfo.java"
         val Right(_) =
-          eval.apply(BuildInfoJavaStatic.run(Task.Anon(Args(runResult.toString))))
+          eval.apply(BuildInfoJavaStatic.run(Task.Anon(Args(runResult.toString)))): @unchecked
 
         assert(
           os.exists(runResult),
@@ -233,7 +233,7 @@ object BuildInfoTests extends TestSuite {
       testModuleSourcesPath / "scala"
     ).scoped { eval =>
       val buildInfoGeneratedSourcesFolder = eval.outPath / "buildInfoSources.dest"
-      val Right(result) = eval.apply(BuildInfoPlain.generatedSources)
+      val Right(result) = eval.apply(BuildInfoPlain.generatedSources): @unchecked
       assert(
         result.value.size == 1,
         os.isDir(result.value.head.path),

contrib/codeartifact/src/mill/contrib/codeartifact/CodeartifactPublishModule.scala

@@ -53,7 +53,7 @@ object CodeartifactPublishModule extends ExternalModule {
         connectTimeout,
         Task.log
       ).publishAll(
-        artifacts: _*
+        artifacts*
       )
     }