Added clean of datadir before run

Author: sksamuel

src/main/scala/scoverage/IOUtils.scala

@@ -10,6 +10,9 @@ object IOUtils {
   private val CoverageFileName = "scoverage.coverage.xml"
   val DataDir = "scoverage-data"
 
+  def clean(dataDir: File): Unit = dataDir.listFiles.foreach(_.delete())
+  def clean(dataDir: String): Unit = clean(new File(dataDir))
+
   def coverageFile(dataDir: File): File = coverageFile(dataDir.getAbsolutePath)
   def coverageFile(dataDir: String): File = new File(dataDir + "/" + CoverageFileName)
 

src/main/scala/scoverage/plugin.scala

@@ -107,6 +107,9 @@ class ScoverageInstrumentationComponent(val global: Global)
   override def newPhase(prev: scala.tools.nsc.Phase): Phase = new Phase(prev) {
 
     override def run(): Unit = {
+      println("[scoverage]: Cleaning datadir")
+      IOUtils.clean(options.dataDir)
+
       println("[scoverage]: Begin instrumentation phase")
       super.run()
       println(s"[scoverage]: Instrumentation completed [${coverage.statements.size} statements]")