Add an option to add newlines to the end of files.

Fixes scala-ide#113 .

README.rst

@@ -482,6 +482,13 @@ If ``false``, start the comment body on a separate line below the opening delimi
    * element of the given list.
    */
 
+newlineAtEndOfFile
+~~~~~~~~~~~~~~~~~~
+
+Default: ``false``
+
+If ``true``, newlines will be added at the end of all formatted files.
+
 placeScaladocAsterisksBeneathSecondAsterisk
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

scalariform/src/main/scala/scalariform/formatter/ScalaFormatter.scala

@@ -40,7 +40,12 @@ abstract class ScalaFormatter extends HasFormattingPreferences with TypeFormatte
     var result = format(topStats)
     for (firstStat ← topStats.firstStatOpt)
       result = result.before(firstStat.firstToken, EnsureNewlineAndIndent(0))
-    result
+
+    if (formattingPreferences(NewlineAtEndOfFile)) {
+      result.before(compilationUnit.eofToken, EnsureNewlineAndIndent(0))
+    } else {
+      result
+    }
   }
 
   /**

scalariform/src/main/scala/scalariform/formatter/preferences/PreferenceDescriptor.scala

@@ -94,7 +94,7 @@ object AllPreferences {
     PreserveSpaceBeforeArguments, AlignParameters, AlignArguments, DoubleIndentClassDeclaration, FormatXml, IndentPackageBlocks,
     AlignSingleLineCaseStatements, AlignSingleLineCaseStatements.MaxArrowIndent, IndentLocalDefs, PreserveDanglingCloseParenthesis, DanglingCloseParenthesis,
     SpaceInsideParentheses, SpaceInsideBrackets, SpacesWithinPatternBinders, MultilineScaladocCommentsStartOnFirstLine, IndentWithTabs,
-    CompactControlReadability, PlaceScaladocAsterisksBeneathSecondAsterisk, SpacesAroundMultiImports
+    CompactControlReadability, PlaceScaladocAsterisksBeneathSecondAsterisk, SpacesAroundMultiImports, NewlineAtEndOfFile
   )
 
   val preferencesByKey: Map[String, PreferenceDescriptor[_]] =
@@ -244,3 +244,9 @@ case object SpacesAroundMultiImports extends BooleanPreferenceDescriptor {
   val description = "Place spaces around multi imports (import a.{ b, c, d }"
   val defaultValue = false
 }
+
+case object NewlineAtEndOfFile extends BooleanPreferenceDescriptor {
+  val key = "newlineAtEndOfFile"
+  val description = "Add a newline at the end of all files"
+  val defaultValue = false
+}

scalariform/src/test/scala/scalariform/formatter/NewlineAtEndOfFileFormatterTest.scala

@@ -0,0 +1,41 @@
+package scalariform.formatter
+
+import scalariform.parser.{CompilationUnit, ScalaParser}
+import scalariform.formatter.preferences.{FormattingPreferences, NewlineAtEndOfFile}
+
+/** Tests that top-level parses add a newline when NewlineAtEndOfFile is set. */
+class NewlineAtEndOfFileFormatterTest extends AbstractFormatterTest {
+  type Result = CompilationUnit
+
+  // Must parse as a full script to verify the newline formatting.
+  def parse(parser: ScalaParser) = parser.scriptBody()
+
+  def format(formatter: ScalaFormatter, result: Result) = formatter.format(result)(FormatterState())
+
+  override val debug = false
+
+  {
+  implicit val formattingPreferences = FormattingPreferences.setPreference(NewlineAtEndOfFile, true)
+
+  // No newline; should have one added.
+  """import foo.bar
+  |
+  |class Foo {
+  |}""" ==>
+  """import foo.bar
+  |
+  |class Foo {
+  |}
+  |"""
+
+  // Has newline; should stay the same.
+  """import foo.bar
+  |class Foo {
+  |}
+  |""" ==>
+  """import foo.bar
+  |class Foo {
+  |}
+  |"""
+  }
+}