refactor scalafmt to new plugin style

turn replaceSections into helper function instead of trait method

proguard scalafmt build currently suffers from non-deterministic
formatting. Try a few times to reproduce commited Proguard.scala

2 files changed, 89 insertions, 58 deletions

diff --git a/plugins/scalafmt/Scalafmt.scala b/plugins/scalafmt/Scalafmt.scala
index 5f4e054..9d42cbd 100644
--- a/plugins/scalafmt/Scalafmt.scala
+++ b/plugins/scalafmt/Scalafmt.scala
@@ -8,75 +8,106 @@ import java.io.File
 import java.nio.file.Files._
 import java.nio.file._
 
-/**
-  * This plugin provides scalafmt support for cbt.
-  *
-  */
+/** This plugin provides scalafmt support for cbt. */
 trait Scalafmt extends BaseBuild {
-  /**
-    * Reformat scala source code according to `scalafmtConfig` rules
-    *
-    * @return always returns `ExitCode.Success`
-    */
-  final def scalafmt: ExitCode = Scalafmt.format(sourceFiles, scalafmtConfig)
-
-  /**
-    * Scalafmt formatting config.
-    *
-    * Tries to get style in following order:
-    * • project local .scalafmt.conf
-    * • global ~/.scalafmt.conf
-    * • default scalafmt config
-    *
-    * Override this task if you want to provide
-    * scalafmt config programmatically on your own.
-    */
-  def scalafmtConfig: ScalafmtConfig =
-    Scalafmt.getStyle(
-      project = projectDirectory.toPath,
-      home = Option(System.getProperty("user.home")) map (p => Paths.get(p))
+  /** Reformat scala source code according to `scalafmtConfig` rules */
+  def scalafmt = {
+    val scalafmtLib = new ScalafmtLib(lib)
+    scalafmtLib.format( sourceFiles ).config(
+      scalafmtLib.loadConfig(
+        projectDirectory.toPath
+      ) getOrElse ScalafmtConfig.default
     )
+  }
 }
 
-object Scalafmt {
+class ScalafmtLib(lib: Lib){ scalafmtLib =>
+  def userHome = Option( System.getProperty("user.home") ).map(Paths.get(_))
 
-  def getStyle(project: Path, home: Option[Path]): ScalafmtConfig = {
-    val local = getConfigPath(project)
-    val global = home flatMap getConfigPath
-    val customStyle = for {
-      configPath <- local.orElse(global)
-      style <- StyleCache.getStyleForFile(configPath.toString)
-    } yield style
+  /** Tries to load config from .scalafmt.conf in given directory or fallback directory */
+  def loadConfig( directory: Path, fallback: Option[Path] = userHome ): Option[ScalafmtConfig] = {
+    def findIn( base: Path ): Option[Path] = {
+      Some( base.resolve(".scalafmt.conf").toAbsolutePath ).filter(isRegularFile(_))
+    }
 
-    customStyle.getOrElse(ScalafmtConfig.default)
+    findIn( directory ).orElse( fallback flatMap findIn )
+      .flatMap ( file => StyleCache.getStyleForFile(file.toString) )
   }
 
-  def format(files: Seq[File], style: ScalafmtConfig): ExitCode = {
-    val results = files.filter(_.string endsWith ".scala").map(_.toPath).map{ path =>
-      val original = new String(readAllBytes(path))
-      org.scalafmt.Scalafmt.format(original, style) match {
-        case Formatted.Success(formatted) =>
-          if (original != formatted) {
-            val tmpPath = Paths.get(path.toString ++ ".scalafmt-tmp")
-            write(tmpPath, formatted.getBytes)
-            move(tmpPath, path, StandardCopyOption.REPLACE_EXISTING)
-            Some(1)
-          } else {
-            Some(0)
+  case class format(files: Seq[File]){
+    /**
+      * @param whiteSpaceInParenthesis more of a hack to make up for missing support in Scalafmt. Does not respect alignment and maxColumn.
+      */
+    case class config(
+      config: ScalafmtConfig,
+      whiteSpaceInParenthesis: Boolean = false
+    ) extends (() => Seq[File]){
+      def lib = scalafmtLib
+      def apply = {
+        val (successes, errors) = scalafmtLib.lib.transformFilesOrError(
+          files,
+          org.scalafmt.Scalafmt.format(_, config) match {
+            case Formatted.Success(formatted) => Right(
+              if( whiteSpaceInParenthesis ){
+                scalafmtLib.whiteSpaceInParenthesis(formatted)
+              } else formatted
+            )
+            case Formatted.Failure( e ) => Left( e )
           }
-        case Formatted.Failure(e) =>
-          System.err.println(s"Scalafmt failed for $path\nCause: $e\n")
-          None
+        )
+        if(errors.nonEmpty)
+          throw new RuntimeException(
+            "Scalafmt failed to format some files:\n" ++ errors.map{
+              case (file, error) => file.string ++ ": " ++ error.getMessage
+            }.mkString("\n"),
+            errors.head._2
+          )
+        successes
       }
     }
-    if(results.forall(_.nonEmpty)){
-      System.err.println(s"Formatted ${results.flatten.sum} Scala sources")
-      ExitCode.Success
-    } else ExitCode.Failure
   }
 
-  private def getConfigPath(base: Path): Option[Path] = {
-    Some( base.resolve(".scalafmt.conf").toFile )
-      .collect{ case f if f.exists && f.isFile => f.toPath.toAbsolutePath }
+  private def whiteSpaceInParenthesis: String => String =
+    Seq(
+      "(\\(+)([^\\s\\)])".r.replaceAllIn(_:String, m => m.group(1).mkString(" ") ++ " " ++ m.group(2) ),
+      "([^\\s\\(])(\\)+)".r.replaceAllIn(_:String, m => m.group(1) ++ " " ++ m.group(2).mkString(" ") )
+    ).reduce(_ andThen _)
+
+  def cbtRecommendedConfig = {
+    import org.scalafmt.config._
+    val c = ScalafmtConfig.defaultWithAlign
+    c.copy(
+      maxColumn = 110,
+      continuationIndent = c.continuationIndent.copy(
+        defnSite = 2
+      ),
+      align = c.align.copy(
+        tokens = AlignToken.default ++ Set(
+          // formatting for these alignment tokens seems to be deterministic right now
+          // Maybe because of scala meta. Killing the class loader between runs seems not to help.
+          // Starting a new jvm each time does.
+          AlignToken( "=>", ".*" ),
+          AlignToken( ":", ".*" ),
+          AlignToken( "=", ".*" )
+        ) + AlignToken.caseArrow,
+        arrowEnumeratorGenerator = true,
+        mixedOwners = true
+      ),
+      binPack = c.binPack.copy(
+        parentConstructors = true
+      ),
+      spaces = c.spaces.copy(
+        inImportCurlyBraces = true
+      ),
+      lineEndings = LineEndings.unix,
+      newlines = c.newlines.copy(
+        penalizeSingleSelectMultiArgList = false
+      ),
+      runner = c.runner.copy(
+        optimizer = c.runner.optimizer.copy(
+          forceConfigStyleOnOffset = -1
+        )
+      )
+    )
   }
 }
diff --git a/plugins/scalafmt/build/build.scala b/plugins/scalafmt/build/build.scala
index b37d769..e592873 100644
--- a/plugins/scalafmt/build/build.scala
+++ b/plugins/scalafmt/build/build.scala
@@ -1,7 +1,7 @@
 import cbt._
 
 class Build(val context: Context) extends Plugin {
-  private val ScalafmtVersion = "0.5.7"
+  private val ScalafmtVersion = "0.6.2"
 
   override def dependencies =
     super.dependencies ++