Add Scalafmt

.scalafmt.conf

@@ -0,0 +1,18 @@
+maxColumn = 100
+project.git = true
+project.excludeFilters = [ /sbt-test/, /input_sources/, /contraband-scala/, /Keys.scala ]
+
+# http://docs.scala-lang.org/style/scaladoc.html recommends the JavaDoc style.
+# scala/scala is written that way too https://github.com/scala/scala/blob/v2.12.2/src/library/scala/Predef.scala
+docstrings = JavaDoc
+
+# This also seems more idiomatic to include whitespace in import x.{ yyy }
+spaces.inImportCurlyBraces = true
+
+# This works around sequence wildcard (`_*`) turning into `_ *`
+spaces.beforeSeqWildcard = true
+
+# Vertical alignment only => for pattern matching
+align.tokens.add = [
+  { code = "=>",  owner = "Case"  }
+]

build.sbt

@@ -58,7 +58,7 @@ def minimalSettings: Seq[Setting[_]] =
   publishPomSettings ++ Release.javaVersionCheckSettings
 
 def baseSettings: Seq[Setting[_]] =
-  minimalSettings ++ Seq(projectComponent) ++ baseScalacOptions ++ Licensed.settings ++ Formatting.settings
+  minimalSettings ++ Seq(projectComponent) ++ baseScalacOptions ++ Licensed.settings
 
 def testedBaseSettings: Seq[Setting[_]] =
   baseSettings ++ testDependencies
@@ -221,7 +221,6 @@ lazy val mainSettingsProj = (project in file("main-settings")).
 // The main integration project for sbt.  It brings all of the projects together, configures them, and provides for overriding conventions.
 lazy val mainProj = (project in file("main")).
   dependsOn(actionsProj, mainSettingsProj, runProj, commandProj).
-  disablePlugins(SbtScalariform).
   settings(
     testedBaseSettings,
     name := "Main",
@@ -277,7 +276,7 @@ def projectsWithMyProvided = allProjects.map(p => p.copy(configurations = (p.con
 lazy val nonRoots = projectsWithMyProvided.map(p => LocalProject(p.id))
 
 def rootSettings = fullDocSettings ++
-  Util.publishPomSettings ++ otherRootSettings ++ Formatting.sbtFilesSettings ++
+  Util.publishPomSettings ++ otherRootSettings ++
   Transform.conscriptSettings(bundledLauncherProj)
 def otherRootSettings = Seq(
   scripted := scriptedTask.evaluated,

project/AutomateScalafmtPlugin.scala

@@ -0,0 +1,67 @@
+import org.scalafmt.bootstrap.ScalafmtBootstrap
+import org.scalafmt.sbt.ScalafmtPlugin
+import sbt._
+import sbt.Keys._
+import sbt.inc.Analysis
+
+// Taken from https://github.com/akka/alpakka/blob/master/project/AutomateScalafmtPlugin.scala
+object AutomateScalafmtPlugin extends AutoPlugin {
+
+  object autoImport {
+    def automateScalafmtFor(configurations: Configuration*): Seq[Setting[_]] =
+      configurations.flatMap { c =>
+        inConfig(c)(
+          Seq(
+            compileInputs.in(compile) := {
+              scalafmtInc.value
+              compileInputs.in(compile).value
+            },
+            sourceDirectories.in(scalafmtInc) := Seq(scalaSource.value),
+            scalafmtInc := {
+              val cache   = streams.value.cacheDirectory / "scalafmt"
+              val include = includeFilter.in(scalafmtInc).value
+              val exclude = excludeFilter.in(scalafmtInc).value
+              val sources =
+                sourceDirectories
+                  .in(scalafmtInc)
+                  .value
+                  .descendantsExcept(include, exclude)
+                  .get
+                  .toSet
+              def format(handler: Set[File] => Unit, msg: String) = {
+                def update(handler: Set[File] => Unit, msg: String)(in: ChangeReport[File],
+                                                                    out: ChangeReport[File]) = {
+                  val label = Reference.display(thisProjectRef.value)
+                  val files = in.modified -- in.removed
+                  Analysis
+                    .counted("Scala source", "", "s", files.size)
+                    .foreach(count => streams.value.log.info(s"$msg $count in $label ..."))
+                  handler(files)
+                  files
+                }
+                FileFunction.cached(cache)(FilesInfo.hash, FilesInfo.exists)(update(handler, msg))(
+                  sources
+                )
+              }
+              def formattingHandler(files: Set[File]) =
+                if (files.nonEmpty) {
+                  val filesArg = files.map(_.getAbsolutePath).mkString(",")
+                  ScalafmtBootstrap.main(List("--quiet", "-i", "-f", filesArg))
+                }
+              format(formattingHandler, "Formatting")
+              format(_ => (), "Reformatted") // Recalculate the cache
+            }
+          )
+        )
+      }
+  }
+
+  private val scalafmtInc = taskKey[Unit]("Incrementally format modified sources")
+
+  override def requires = ScalafmtPlugin
+
+  override def trigger = allRequirements
+
+  override def projectSettings =
+    (includeFilter.in(scalafmtInc) := "*.scala") +: autoImport.automateScalafmtFor(Compile, Test)
+}

project/Formatting.scala

@@ -1,40 +0,0 @@
-import sbt._, Keys._
-import com.typesafe.sbt.SbtScalariform._, autoImport._
-
-object Formatting {
-  val BuildConfig = config("build") extend Compile
-  val BuildSbtConfig = config("buildsbt") extend Compile
-
-  val scalariformCheck = taskKey[Unit]("Checks that the existing code is formatted, via git diff")
-
-  private val prefs: Seq[Setting[_]] = {
-    import scalariform.formatter.preferences._
-    Seq(
-      scalariformPreferences ~= (_
-        .setPreference(AlignSingleLineCaseStatements, true)
-        .setPreference(AlignSingleLineCaseStatements.MaxArrowIndent, 100)
-        .setPreference(DanglingCloseParenthesis, Force)
-      )
-    )
-  }
-
-  val settings: Seq[Setting[_]] = Seq() ++ prefs
-  val sbtFilesSettings: Seq[Setting[_]] = Seq() ++ prefs ++
-    inConfig(BuildConfig)(configScalariformSettings) ++
-    inConfig(BuildSbtConfig)(configScalariformSettings) ++
-    Seq(
-      scalaSource in BuildConfig := baseDirectory.value / "project",
-      scalaSource in BuildSbtConfig := baseDirectory.value / "project",
-      includeFilter in (BuildConfig, scalariformFormat) := ("*.scala": FileFilter),
-      includeFilter in (BuildSbtConfig, scalariformFormat) := ("*.sbt": FileFilter),
-      scalariformFormat in Compile := {
-        val x = (scalariformFormat in BuildSbtConfig).value
-        val y = (scalariformFormat in BuildConfig).value
-        (scalariformFormat in Compile).value
-      },
-      scalariformCheck := {
-        val diff = "git diff".!!
-        if (diff.nonEmpty) sys.error("Working directory is dirty!\n" + diff)
-      }
-    )
-}

project/plugins.sbt

@@ -6,7 +6,7 @@ addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "0.1.11")
 addSbtPlugin("com.typesafe.sbt" % "sbt-ghpages" % "0.5.4")
 addSbtPlugin("com.typesafe.sbt" % "sbt-git" % "0.8.5")
 addSbtPlugin("com.typesafe.sbt" % "sbt-javaversioncheck" % "0.1.0")
-addSbtPlugin("org.scalariform" % "sbt-scalariform" % "1.6.0")
+addSbtPlugin("com.geirsson" % "sbt-scalafmt" % "0.6.8")
 addSbtPlugin("com.typesafe.sbt" % "sbt-site" % "0.8.2")
 addSbtPlugin("me.lessis" % "bintray-sbt" % "0.3.0")
 addSbtPlugin("org.scala-sbt" % "sbt-contraband" % "0.3.0-M4")