Add fmt command

.scalafmt.conf

@@ -1,4 +1,4 @@
-version = "3.0.0"
+version = "3.0.3"
 
 align.preset = more
 maxColumn = 100
@@ -12,6 +12,8 @@ newlines.beforeMultiline = keep
 newlines.afterCurlyLambdaParams = keep
 newlines.alwaysBeforeElseAfterCurlyIf = true
 
+runner.dialect = scala213
+
 fileOverride {
   "glob:**/scala-3-stable/**" {
     runner.dialect = scala3

build.sc

@@ -100,16 +100,23 @@ object `generate-reference-doc` extends SbtModule {
 }
 
 object dummy extends Module {
-  // dummy project to get scala steward updates for Ammonite, whose
-  // version is used in the repl command, and ensure Ammonite is available
-  // for all Scala versions we support
+  // dummy projects to get scala steward updates for Ammonite and scalafmt, whose
+  // versions are used in the fmt and repl commands, and ensure Ammonite is available
+  // for all Scala versions we support.
   object amm extends Cross[Amm](Scala.listAll: _*)
   class Amm(val crossScalaVersion: String) extends CrossScalaModule with Bloop.Module {
     def skipBloop = true
     def ivyDeps = Agg(
       Deps.ammonite
     )
   }
+  object scalafmt extends ScalaModule with Bloop.Module {
+    def skipBloop    = true
+    def scalaVersion = Scala.defaultInternal
+    def ivyDeps = Agg(
+      Deps.scalafmtCli
+    )
+  }
 }
 
 class BuildMacros(val crossScalaVersion: String) extends CrossSbtModule with ScalaCliPublishModule {
@@ -134,6 +141,9 @@ class Build(val crossScalaVersion: String)
   def repositories = super.repositories ++ Seq(
     coursier.Repositories.sonatype("snapshots")
   )
+  def compileIvyDeps = super.compileIvyDeps() ++ Agg(
+    Deps.svm
+  )
   def ivyDeps = super.ivyDeps() ++ Agg(
     Deps.asm,
     Deps.bloopConfig,
@@ -218,6 +228,8 @@ class Build(val crossScalaVersion: String)
          |
          |  def ammoniteVersion = "${Deps.ammonite.dep.version}"
          |
+         |  def defaultScalafmtVersion = "${Deps.scalafmtCli.dep.version}"
+         |
          |  def defaultScalaVersion = "${Scala.defaultUser}"
          |}
          |""".stripMargin

examples/cross-build/Hello.js.scala

@@ -0,0 +1,11 @@
+// using scala 2.13
+// require scala-js
+
+import scala.scalajs.js
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val console = js.Dynamic.global.console
+    console.log("Hello from Scala.JS")
+  }
+}

examples/cross-build/Hello.native.scala

@@ -0,0 +1,14 @@
+// using scala 2.13
+// require scala-native
+
+import scala.scalanative.libc._
+import scala.scalanative.unsafe._
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val message = "Hello from Scala Native\n"
+    Zone { implicit z =>
+      stdio.printf(toCString(message))
+    }
+  }
+}

modules/build/src/main/java/scala/build/internal/Chdir.java

@@ -0,0 +1,15 @@
+package scala.build.internal;
+
+import coursier.jvm.ErrnoException;
+
+public final class Chdir {
+
+  public static boolean available() {
+    return false;
+  }
+
+  public static void chdir(String path) throws ErrnoException {
+    // Not supported on the JVM, returning immediately
+  }
+
+}

modules/build/src/main/java/scala/build/internal/ChdirGraalvm.java

@@ -0,0 +1,37 @@
+package scala.build.internal;
+
+import java.io.FileNotFoundException;
+
+import com.oracle.svm.core.CErrorNumber;
+import com.oracle.svm.core.annotate.Substitute;
+import com.oracle.svm.core.annotate.TargetClass;
+import coursier.jvm.ErrnoException;
+import coursier.jvm.GraalvmErrnoExtras;
+import org.graalvm.nativeimage.c.type.CTypeConversion;
+import org.graalvm.nativeimage.Platform;
+import org.graalvm.nativeimage.Platforms;
+
+@TargetClass(className = "scala.build.internal.Chdir")
+@Platforms({Platform.LINUX.class, Platform.DARWIN.class})
+final class ChdirGraalvm {
+
+  @Substitute
+  public static boolean available() {
+    return true;
+  }
+
+  @Substitute
+  public static void chdir(String path) throws ErrnoException {
+    CTypeConversion.CCharPointerHolder path0 = CTypeConversion.toCString(path);
+    int ret = GraalvmUnistdExtras.chdir(path0.get());
+
+    if (ret != 0) {
+      int n = CErrorNumber.getCErrorNumber();
+      Throwable cause = null;
+      if (n == GraalvmErrnoExtras.ENOENT() || n == GraalvmErrnoExtras.ENOTDIR())
+        cause = new FileNotFoundException(path);
+      throw new ErrnoException(n, cause);
+    }
+  }
+
+}

modules/build/src/main/java/scala/build/internal/GraalvmUnistdExtras.java

@@ -0,0 +1,18 @@
+package scala.build.internal;
+
+import com.oracle.svm.core.posix.headers.PosixDirectives;
+import org.graalvm.nativeimage.Platform;
+import org.graalvm.nativeimage.Platforms;
+import org.graalvm.nativeimage.c.CContext;
+import org.graalvm.nativeimage.c.function.CFunction;
+import org.graalvm.nativeimage.c.type.CCharPointer;
+import org.graalvm.nativeimage.c.type.CCharPointerPointer;
+
+@CContext(PosixDirectives.class)
+@Platforms({Platform.LINUX.class, Platform.DARWIN.class})
+public class GraalvmUnistdExtras {
+
+    @CFunction
+    public static native int chdir(CCharPointer path);
+
+}

modules/build/src/main/scala/scala/build/internal/OsLibc.scala

@@ -9,7 +9,7 @@ import scala.util.Properties
 
 object OsLibc {
 
-  private lazy val isMusl: Option[Boolean] = {
+  lazy val isMusl: Option[Boolean] = {
 
     def tryRun(cmd: String*): Option[os.CommandResult] =
       try {

modules/build/src/main/scala/scala/build/internal/Runner.scala

@@ -18,7 +18,8 @@ object Runner {
     commandName: String,
     command: Seq[String],
     logger: Logger,
-    allowExecve: Boolean = false
+    allowExecve: Boolean = false,
+    cwd: Option[os.Path] = None
   ): Int = {
 
     import logger.{log, debug}
@@ -31,18 +32,24 @@ object Runner {
 
     if (allowExecve && Execve.available()) {
       debug("execve available")
+
+      for (dir <- cwd)
+        Chdir.chdir(dir.toString)
+
       Execve.execve(
         findInPath(command.head).fold(command.head)(_.toString),
         commandName +: command.tail.toArray,
         sys.env.toArray.sorted.map { case (k, v) => s"$k=$v" }
       )
       sys.error("should not happen")
     }
-    else
-      new ProcessBuilder(command: _*)
+    else {
+      val b = new ProcessBuilder(command: _*)
         .inheritIO()
-        .start()
-        .waitFor()
+      for (dir <- cwd)
+        b.directory(dir.toIO)
+      b.start().waitFor()
+    }
   }
 
   def runJvm(

modules/cli/src/main/scala/scala/cli/ScalaCli.scala

@@ -21,6 +21,7 @@ object ScalaCli extends CommandsEntryPoint {
     Compile,
     Directories,
     Export,
+    Fmt,
     InstallCompletions,
     Metabrowse,
     Repl,

modules/cli/src/main/scala/scala/cli/commands/Fmt.scala

@@ -0,0 +1,54 @@
+package scala.cli.commands
+
+import caseapp._
+
+import scala.build.Inputs
+import scala.build.internal.Runner
+import scala.cli.internal.FetchExternalBinary
+
+object Fmt extends ScalaCommand[FmtOptions] {
+  override def group                              = "Miscellaneous"
+  override def sharedOptions(options: FmtOptions) = Some(options.shared)
+  def run(options: FmtOptions, args: RemainingArgs): Unit = {
+
+    // TODO If no input is given, just pass '.' to scalafmt?
+    val (sourceFiles, workspace) =
+      if (args.remaining.isEmpty)
+        (Seq(os.pwd), os.pwd)
+      else {
+        val i = options.shared.inputsOrExit(args)
+        val s = i.sourceFiles().collect {
+          case sc: Inputs.Script    => sc.path
+          case sc: Inputs.ScalaFile => sc.path
+        }
+        (s, i.workspace)
+      }
+
+    val logger = options.shared.logger
+    val cache  = options.shared.coursierCache
+
+    if (sourceFiles.isEmpty)
+      logger.debug("No source files, not formatting anything")
+    else {
+
+      val fmtLauncher = options.scalafmtLauncher.filter(_.nonEmpty) match {
+        case Some(launcher) =>
+          os.Path(launcher, os.pwd)
+        case None =>
+          val (url, changing) = options.binaryUrl
+          FetchExternalBinary.fetch(url, changing, cache, logger, "scalafmt")
+      }
+
+      logger.debug(s"Using scalafmt launcher $fmtLauncher")
+
+      val command = Seq(fmtLauncher.toString) ++ sourceFiles.map(_.toString)
+      Runner.run(
+        "scalafmt",
+        command,
+        logger,
+        allowExecve = true,
+        cwd = Some(workspace)
+      )
+    }
+  }
+}

modules/cli/src/main/scala/scala/cli/commands/FmtOptions.scala

@@ -0,0 +1,41 @@
+package scala.cli.commands
+
+import caseapp._
+
+import scala.build.internal.Constants
+import scala.cli.internal.FetchExternalBinary
+import scala.util.Properties
+
+// format: off
+@HelpMessage("Format Scala code")
+final case class FmtOptions(
+  @Recurse
+    shared: SharedOptions = SharedOptions(),
+  @HelpMessage("Check that sources are well formatted")
+    check: Boolean = false,
+
+  @Hidden
+    osArchSuffix: Option[String] = None,
+  @Hidden
+    scalafmtTag: Option[String] = None,
+  @Hidden
+    scalafmtGitHubOrgName: Option[String] = None,
+  @Hidden
+    scalafmtExtension: Option[String] = None,
+  @Hidden
+    scalafmtLauncher: Option[String] = None
+) {
+  // format: on
+
+  def binaryUrl: (String, Boolean) = {
+    val osArchSuffix0 = osArchSuffix.map(_.trim).filter(_.nonEmpty)
+      .getOrElse(FetchExternalBinary.platformSuffix())
+    val tag0           = scalafmtTag.getOrElse("v" + Constants.defaultScalafmtVersion)
+    val gitHubOrgName0 = scalafmtGitHubOrgName.getOrElse("alexarchambault/scalafmt-native-image")
+    val extension0     = if (Properties.isWin) ".zip" else ".gz"
+    val url =
+      s"https://github.com/$gitHubOrgName0/releases/download/$tag0/scalafmt-$osArchSuffix0$extension0"
+    (url, !tag0.startsWith("v"))
+  }
+
+}