Ensure utf8 encoding is defaulted everywhere.

scalac-scoverage-plugin/src/main/scala/scoverage/IOUtils.scala

@@ -17,7 +17,6 @@ object IOUtils {
 
   private val UnixSeperator: Char = '/'
   private val WindowsSeperator: Char = '\\'
-  private val UTF8Encoding: String = "UTF-8"
 
   def getName(path: String): Any = {
     val index = {
@@ -37,9 +36,12 @@ object IOUtils {
     findMeasurementFiles(dataDir).foreach(_.delete)
   def clean(dataDir: String): Unit = clean(new File(dataDir))
 
-  def writeToFile(file: File, str: String) = {
+  def writeToFile(file: File, str: String)(implicit encoding: String) = {
     val writer = new BufferedWriter(
-      new OutputStreamWriter(new FileOutputStream(file), UTF8Encoding)
+      new OutputStreamWriter(
+        new FileOutputStream(file),
+        encoding
+      )
     )
     try {
       writer.write(str)
@@ -86,10 +88,13 @@ object IOUtils {
     file.getName == Constants.XMLReportFilenameWithDebug
 
   // loads all the invoked statement ids from the given files
-  def invoked(files: Seq[File]): Set[(Int, String)] = {
+  def invoked(
+      files: Seq[File]
+  )(implicit encoding: String): Set[(Int, String)] = {
     val acc = mutable.Set[(Int, String)]()
     files.foreach { file =>
-      val reader = Source.fromFile(file)
+      val reader =
+        Source.fromFile(file, encoding)
       for (line <- reader.getLines()) {
         if (!line.isEmpty) {
           acc += (line.split(" ").toList match {

scalac-scoverage-plugin/src/main/scala/scoverage/report/BaseReportWriter.scala

@@ -2,7 +2,15 @@ package scoverage.report
 
 import java.io.File
 
-class BaseReportWriter(sourceDirectories: Seq[File], outputDir: File) {
+import scala.io.Codec
+
+class BaseReportWriter(
+    sourceDirectories: Seq[File],
+    outputDir: File,
+    sourceEncoding: Option[String]
+) {
+
+  implicit val encoding = sourceEncoding.fold(Codec.UTF8.name)(identity)
 
   // Source paths in canonical form WITH trailing file separator
   private val formattedSourcePaths: Seq[String] =

scalac-scoverage-plugin/src/main/scala/scoverage/report/CoberturaXmlWriter.scala

@@ -9,11 +9,14 @@ import scoverage.DoubleFormat.twoFractionDigits
 import scoverage._
 
 /** @author Stephen Samuel */
-class CoberturaXmlWriter(sourceDirectories: Seq[File], outputDir: File)
-    extends BaseReportWriter(sourceDirectories, outputDir) {
+class CoberturaXmlWriter(
+    sourceDirectories: Seq[File],
+    outputDir: File,
+    sourceEncoding: Option[String]
+) extends BaseReportWriter(sourceDirectories, outputDir, sourceEncoding) {
 
-  def this(baseDir: File, outputDir: File) = {
-    this(Seq(baseDir), outputDir)
+  def this(baseDir: File, outputDir: File, sourceEncoding: Option[String]) = {
+    this(Seq(baseDir), outputDir, sourceEncoding)
   }
 
   def write(coverage: Coverage): Unit = {

scalac-scoverage-plugin/src/main/scala/scoverage/report/CodeGrid.scala

@@ -1,5 +1,6 @@
 package scoverage.report
 
+import scala.io.Codec
 import scala.io.Source
 
 import _root_.scoverage.MeasuredFile
@@ -77,7 +78,7 @@ class CodeGrid(mFile: MeasuredFile, sourceEncoding: Option[String]) {
   private def source(mfile: MeasuredFile): String = {
     val src = sourceEncoding match {
       case Some(enc) => Source.fromFile(mfile.source, enc)
-      case None      => Source.fromFile(mfile.source)
+      case None      => Source.fromFile(mfile.source, Codec.UTF8.name)
     }
     try src.mkString
     finally src.close()

scalac-scoverage-plugin/src/main/scala/scoverage/report/CoverageAggregator.scala

@@ -2,12 +2,16 @@ package scoverage.report
 
 import java.io.File
 
+import scala.io.Codec
+
 import scoverage.Coverage
 import scoverage.IOUtils
 import scoverage.Serializer
 
 object CoverageAggregator {
 
+  implicit val encoding: String = Codec.UTF8.name
+
   // to be used by gradle-scoverage plugin
   def aggregate(dataDirs: Array[File], sourceRoot: File): Option[Coverage] =
     aggregate(

scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageHtmlWriter.scala

@@ -12,7 +12,7 @@ class ScoverageHtmlWriter(
     sourceDirectories: Seq[File],
     outputDir: File,
     sourceEncoding: Option[String]
-) extends BaseReportWriter(sourceDirectories, outputDir) {
+) extends BaseReportWriter(sourceDirectories, outputDir, sourceEncoding) {
 
   // to be used by gradle-scoverage plugin
   def this(

scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageXmlWriter.scala

@@ -11,11 +11,17 @@ import scoverage._
 class ScoverageXmlWriter(
     sourceDirectories: Seq[File],
     outputDir: File,
-    debug: Boolean
-) extends BaseReportWriter(sourceDirectories, outputDir) {
+    debug: Boolean,
+    sourceEncoding: Option[String]
+) extends BaseReportWriter(sourceDirectories, outputDir, sourceEncoding) {
 
-  def this(sourceDir: File, outputDir: File, debug: Boolean) = {
-    this(Seq(sourceDir), outputDir, debug)
+  def this(
+      sourceDir: File,
+      outputDir: File,
+      debug: Boolean,
+      sourceEncoding: Option[String]
+  ) = {
+    this(Seq(sourceDir), outputDir, debug, sourceEncoding)
   }
 
   def write(coverage: Coverage): Unit = {

scalac-scoverage-plugin/src/test/scala/scoverage/CoberturaXmlWriterTest.scala

@@ -213,7 +213,7 @@ class CoberturaXmlWriterTest extends FunSuite {
         )
       )
 
-    val writer = new CoberturaXmlWriter(sourceRoot, dir)
+    val writer = new CoberturaXmlWriter(sourceRoot, dir, None)
     writer.write(coverage)
 
     val domFactory = DocumentBuilderFactory.newInstance()
@@ -309,7 +309,7 @@ class CoberturaXmlWriterTest extends FunSuite {
         )
       )
 
-    val writer = new CoberturaXmlWriter(sourceRoot, dir)
+    val writer = new CoberturaXmlWriter(sourceRoot, dir, None)
     writer.write(coverage)
 
     // Needed to acount for https://github.com/scala/scala-xml/pull/177

scalac-scoverage-plugin/src/test/scala/scoverage/IOUtilsTest.scala

@@ -4,11 +4,15 @@ import java.io.File
 import java.io.FileWriter
 import java.util.UUID
 
+import scala.io.Codec
+
 import munit.FunSuite
 
 /** @author Stephen Samuel */
 class IOUtilsTest extends FunSuite {
 
+  implicit val encoding: String = Codec.UTF8.name
+
   test("should parse measurement files") {
     val file = File.createTempFile("scoveragemeasurementtest", "txt")
     val writer = new FileWriter(file)

scalac-scoverage-plugin/src/test/scala/scoverage/LocationCompiler.scala

@@ -2,6 +2,7 @@ package scoverage
 
 import java.io.File
 
+import scala.io.Codec
 import scala.tools.nsc.Global
 import scala.tools.nsc.plugins.PluginComponent
 import scala.tools.nsc.transform.Transform
@@ -24,7 +25,7 @@ class LocationCompiler(
 
   def writeCodeSnippetToTempFile(code: String): File = {
     val file = File.createTempFile("code_snippet", ".scala")
-    IOUtils.writeToFile(file, code)
+    IOUtils.writeToFile(file, code)(Codec.UTF8.name)
     file.deleteOnExit()
     file
   }

scalac-scoverage-plugin/src/test/scala/scoverage/ScoverageCompiler.scala

@@ -5,6 +5,7 @@ import java.io.FileNotFoundException
 import java.net.URL
 
 import scala.collection.mutable.ListBuffer
+import scala.io.Codec
 import scala.tools.nsc.Global
 import scala.tools.nsc.Settings
 import scala.tools.nsc.plugins.PluginComponent
@@ -135,7 +136,7 @@ class ScoverageCompiler(
 
   def writeCodeSnippetToTempFile(code: String): File = {
     val file = File.createTempFile("scoverage_snippet", ".scala")
-    IOUtils.writeToFile(file, code)
+    IOUtils.writeToFile(file, code)(Codec.UTF8.name)
     file.deleteOnExit()
     file
   }

scalac-scoverage-runtime/jvm/src/test/scala/scoverage/InvokerConcurrencyTest.scala

@@ -36,7 +36,7 @@ class InvokerConcurrencyTest extends FunSuite {
       }
     }
 
-    futures.foreach(Await.result(_, 1.second))
+    futures.foreach(Await.result(_, 3.second))
 
     // Now verify that the measurement file is not corrupted by loading it
     val measurementFiles = Invoker.findMeasurementFiles(measurementDir)