Add package-private option

src/main/scala/sbtbuildinfo/BuildInfoOption.scala

@@ -9,4 +9,5 @@ object BuildInfoOption {
   case object ToJson extends BuildInfoOption
   case class Traits(names: String*) extends BuildInfoOption
   case object BuildTime extends BuildInfoOption
+  case object PackagePrivate extends BuildInfoOption
 }

src/main/scala/sbtbuildinfo/BuildInfoRenderer.scala

@@ -6,10 +6,12 @@ object BuildInfoRenderer {
 
 trait BuildInfoRenderer {
 
+  def options: Seq[BuildInfoOption]
   def fileType: BuildInfoType
   def extension: String
   def renderKeys(infoKeysNameAndValues: Seq[BuildInfoResult]): Seq[String]
 
   def isSource = fileType == BuildInfoType.Source
   def isResource = fileType == BuildInfoType.Resource
+  def isPkgPriv: Boolean = options contains BuildInfoOption.PackagePrivate
 }

src/main/scala/sbtbuildinfo/ScalaCaseClassRenderer.scala

@@ -33,7 +33,7 @@ case class ScalaCaseClassRenderer(options: Seq[BuildInfoOption], pkg: String, ob
       caseObjectLine(buildInfoResults)
 
   private def caseClassDefinitionBegin = List(
-    s"case class $obj("
+    withPkgPriv(s"case class $obj(")
   )
 
   private def caseClassParameter(r: BuildInfoResult): Seq[String] = {
@@ -57,7 +57,7 @@ case class ScalaCaseClassRenderer(options: Seq[BuildInfoOption], pkg: String, ob
   private def caseClassEnd = List("}")
 
   private def caseObjectLine(buildInfoResults: Seq[BuildInfoResult]) = List(
-    s"case object $obj {",
+    withPkgPriv(s"case object $obj {"),
     s"  def apply(): $obj = new $obj(${buildInfoResults.map(r => s"\n    ${r.identifier} = ${quote(r.value)}").mkString(",")})",
     s"  val get = apply()",
     s"  val value = apply()",

src/main/scala/sbtbuildinfo/ScalaCaseObjectRenderer.scala

@@ -19,7 +19,7 @@ private[sbtbuildinfo] case class ScalaCaseObjectRenderer(options: Seq[BuildInfoO
     "import scala.Predef._",
     "",
     s"/** This object was generated by sbt-buildinfo. */",
-    s"case object $obj$objTraits {"
+    withPkgPriv(s"case object $obj$objTraits {")
   )
 
   def footer = List("}")

src/main/scala/sbtbuildinfo/ScalaFinalCaseObjectRenderer.scala

@@ -19,7 +19,7 @@ case class ScalaFinalCaseObjectRenderer(options: Seq[BuildInfoOption], pkg: Stri
     "import scala.Predef._",
     "",
     s"/** This object was generated by sbt-buildinfo. */",
-    s"case object $obj$objTraits {"
+    withPkgPriv(s"case object $obj$objTraits {")
   )
 
   def footer = List("}")

src/main/scala/sbtbuildinfo/ScalaRenderer.scala

@@ -1,6 +1,9 @@
 package sbtbuildinfo
 
 abstract class ScalaRenderer extends BuildInfoRenderer {
+
+  protected def pkg: String
+
   protected def getType(typeExpr: TypeExpression): Option[String] = {
     def tpeToReturnType(tpe: TypeExpression): Option[String] =
       tpe match {
@@ -62,5 +65,9 @@ abstract class ScalaRenderer extends BuildInfoRenderer {
     str.replace("\\","\\\\").replace("\n","\\n").replace("\b","\\b").replace("\r","\\r").
       replace("\t","\\t").replace("\'","\\'").replace("\f","\\f").replace("\"","\\\"")
 
+  protected def withPkgPriv(str: String): String =
+    if(pkg.nonEmpty && isPkgPriv)
+      s"private[${pkg.split('.').last}] $str"
+    else str
 
 }

src/sbt-test/sbt-buildinfo/options/build.sbt

@@ -15,7 +15,8 @@ lazy val root = (project in file(".")).
       BuildInfoOption.ToJson,
       BuildInfoOption.ToMap,
       BuildInfoOption.Traits("TestTrait1", "TestTrait2"),
-      BuildInfoOption.Traits("TestTrait3")),
+      BuildInfoOption.Traits("TestTrait3"),
+      BuildInfoOption.PackagePrivate),
     homepage := Some(url("http://example.com")),
     licenses := Seq("MIT License" -> url("https://github.com/sbt/sbt-buildinfo/blob/master/LICENSE")),
     check := {
@@ -27,7 +28,7 @@ lazy val root = (project in file(".")).
              """import scala.Predef._""" ::
              """""" ::
              """/** This object was generated by sbt-buildinfo. */""" ::
-             """case object BuildInfo extends TestTrait1 with TestTrait2 with TestTrait3 {""" ::
+             """private[hello] case object BuildInfo extends TestTrait1 with TestTrait2 with TestTrait3 {""" ::
              """  /** The value is "helloworld". */"""::
              """  val name: String = "helloworld"""" ::
              """  /** The value is "2.12.7". */""" ::