Add fmt command

Author: alexarchambault

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 {
@@ -221,6 +228,8 @@ class Build(val crossScalaVersion: String)
          |
          |  def ammoniteVersion = "${Deps.ammonite.dep.version}"
          |
+         |  def defaultScalafmtVersion = "${Deps.scalafmtCli.dep.version}"
+         |
          |  def defaultScalaVersion = "${Scala.defaultUser}"
          |}
          |""".stripMargin

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"))
+  }
+
+}

modules/integration/src/test/scala/scala/cli/integration/FmtTests.scala

@@ -0,0 +1,49 @@
+package scala.cli.integration
+
+import com.eed3si9n.expecty.Expecty.expect
+
+class FmtTests extends munit.FunSuite {
+
+  val simpleInputs = TestInputs(
+    Seq(
+      os.rel / ".scalafmt.conf" ->
+        """runner.dialect = scala213
+          |""".stripMargin,
+      os.rel / "Foo.scala" ->
+        """package foo
+          |
+          |    object Foo       extends       java.lang.Object  {
+          |                     def           get()             = 2
+          | }
+          |""".stripMargin
+    )
+  )
+  val expectedSimpleInputsFormattedContent = noCrLf {
+    """package foo
+      |
+      |object Foo extends java.lang.Object {
+      |  def get() = 2
+      |}
+      |""".stripMargin
+  }
+
+  private def noCrLf(input: String): String =
+    input.replaceAll("\r\n", "\n")
+
+  test("simple") {
+    simpleInputs.fromRoot { root =>
+      os.proc(TestUtil.cli, "fmt", ".").call(cwd = root)
+      val updatedContent = noCrLf(os.read(root / "Foo.scala"))
+      expect(updatedContent == expectedSimpleInputsFormattedContent)
+    }
+  }
+
+  test("no inputs") {
+    simpleInputs.fromRoot { root =>
+      os.proc(TestUtil.cli, "fmt").call(cwd = root)
+      val updatedContent = noCrLf(os.read(root / "Foo.scala"))
+      expect(updatedContent == expectedSimpleInputsFormattedContent)
+    }
+  }
+
+}

project/deps.sc

@@ -52,6 +52,7 @@ object Deps {
   def scala3Compiler(sv: String) = ivy"org.scala-lang::scala3-compiler:$sv"
   def scalaAsync                 = ivy"org.scala-lang.modules::scala-async:0.10.0"
   def scalac(sv: String)         = ivy"org.scala-lang:scala-compiler:$sv"
+  def scalafmtCli                = ivy"org.scalameta::scalafmt-cli:3.0.3"
   def scalaJsEnvNodeJs           = ivy"org.scala-js::scalajs-env-nodejs:1.1.1"
   def scalaJsLinker              = ivy"org.scala-js::scalajs-linker:${Versions.scalaJs}"
   def scalaJsLinkerInterface     = ivy"org.scala-js::scalajs-linker-interface:${Versions.scalaJs}"

website/docs/reference/cli-options.md

@@ -53,6 +53,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -126,6 +127,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -156,6 +158,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -192,6 +195,28 @@ Available in commands:
 
 Aliases: `-o`
 
+## Fmt options
+
+Available in commands:
+- [`fmt`](./commands#fmt)
+
+
+<!-- Automatically generated, DO NOT EDIT MANUALLY -->
+
+#### `--check`
+
+Check that sources are well formatted
+
+#### `--os-arch-suffix`
+
+#### `--scalafmt-tag`
+
+#### `--scalafmt-git-hub-org-name`
+
+#### `--scalafmt-extension`
+
+#### `--scalafmt-launcher`
+
 ## Help options
 
 Available in commands:
@@ -204,6 +229,7 @@ Available in commands:
 - [`compile`](./commands#compile)
 - [`directories`](./commands#directories)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`install completions`](./commands#install-completions)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
@@ -280,6 +306,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -321,6 +348,7 @@ Available in commands:
 - [`clean`](./commands#clean)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`install completions`](./commands#install-completions)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
@@ -588,6 +616,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -620,6 +649,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -658,6 +688,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)
@@ -698,6 +729,7 @@ Available in commands:
 - [`bsp`](./commands#bsp)
 - [`compile`](./commands#compile)
 - [`export`](./commands#export)
+- [`fmt`](./commands#fmt)
 - [`browse` / `metabrowse`](./commands#browse)
 - [`package`](./commands#package)
 - [`console` / `repl`](./commands#console)

website/docs/reference/commands.md

@@ -62,6 +62,22 @@ Accepts options:
 - [scalac](./cli-options.md#scalac-options)
 - [shared](./cli-options.md#shared-options)
 
+## `fmt`
+
+Format Scala code
+
+Accepts options:
+- [compilation server](./cli-options.md#compilation-server-options)
+- [coursier](./cli-options.md#coursier-options)
+- [dependency](./cli-options.md#dependency-options)
+- [fmt](./cli-options.md#fmt-options)
+- [jvm](./cli-options.md#jvm-options)
+- [logging](./cli-options.md#logging-options)
+- [Scala.JS](./cli-options.md#scalajs-options)
+- [Scala Native](./cli-options.md#scala-native-options)
+- [scalac](./cli-options.md#scalac-options)
+- [shared](./cli-options.md#shared-options)
+
 ## `install completions`
 
 Accepts options: