fix(coverage): fix for absolute vs relative paths

fix for maven sending absolute paths and sonar-runner sending relative paths

src/main/scala/com/buransky/plugins/scoverage/xml/XmlScoverageReportConstructingParser.scala

@@ -143,7 +143,10 @@ class XmlScoverageReportConstructingParser(source: Source, pathSanitizer: PathSa
       val childNodes = children.map(_.toStatementCoverage)
 
       childNodes match {
-        case Nil => coverage.get
+        case Nil => coverage match {
+          case None => FileStatementCoverage("Nothing", 0, 0, List.empty[CoveredStatement])
+          case _ => coverage.get
+        }
         case _ => DirectoryStatementCoverage(name, childNodes)
       }
     }
@@ -224,4 +227,4 @@ class XmlScoverageReportConstructingParser(source: Source, pathSanitizer: PathSa
 
   private def coveredStatements(statements: Iterable[CoveredStatement]) =
     statements.count(_.hitCount > 0)
-}
+}

src/test/scala/com/buransky/plugins/scoverage/xml/XmlScoverageReportConstructingParserSpec.scala

@@ -34,6 +34,16 @@ import com.buransky.plugins.scoverage.NodeStatementCoverage
 class XmlScoverageReportConstructingParserSpec extends FlatSpec with Matchers {
   behavior of "parse source"
 
+  it must "parse empty coverage file correctly" in {
+    val sanitizer = new PathSanitizer() {
+      def getSourceRelativePath(path: Seq[String]): Option[Seq[String]] = {
+        // do nothing
+        Some(path)
+      }
+    }
+    assertReportFile(XmlReportFile1.emptyCoverage, 0, sanitizer)(assertEmptyCoverage)
+  }
+
   it must "parse old broken Scoverage 0.95 file correctly" in {
     val sanitizer = new PathSanitizer() {
       def getSourceRelativePath(path: Seq[String]): Option[Seq[String]] = {
@@ -130,4 +140,15 @@ class XmlScoverageReportConstructingParserSpec extends FlatSpec with Matchers {
 
     node.children
   }
+
+  private def assertEmptyCoverage(projectCoverage: ProjectStatementCoverage): Unit = {
+    // Assert structure
+    projectCoverage.name should equal("")
+
+    val projectChildren = projectCoverage.children.toList
+    projectChildren.length should equal(0)
+    projectCoverage.coveredStatementsCount should equal(0)
+    projectCoverage.statementCount should equal(0)
+    projectCoverage.coveredStatementsCount should equal(0)
+  }
 }

src/test/scala/com/buransky/plugins/scoverage/xml/data/XmlReportFile1.scala

@@ -834,4 +834,10 @@ object XmlReportFile1 {
       |    </packages>
       |</scoverage>
     """.stripMargin
+
+  val emptyCoverage =
+    """<scoverage
+      |statement-count="0" statements-invoked="0" statement-rate="100.00" branch-rate="100.00" version="1.0" timestamp="1502284526688">
+      |    <packages> </packages>
+      |</scoverage>""".stripMargin
 }