how to interpret scoverage.xml report

Question

I am using the scoverage in Scala project. During the build, I generate coverage HTML and XML reports. I need to parse the XML file (ie scoverage.xml ) to extract metrics for each class on: * lines coverage: number of covered ones vs total * statements coverage: number of covered ones vs total * branches coverage: number of covered ones vs total * functions coverage: number of covered ones vs total

Looking at the scoverage repo, I see that the report is generated by ScoverageXmlWriter.scala but it is not documented!!

So here is an example output of the statement tag :

<statement package="<package>" class="<class>" class-type="Object" full-class-name="<package>.<class>" source="/path/to/<package>/<class>.scala" method="compileScala" start="350" end="350" line="18" branch="false" invocation-count="1" ignored="false">
</statement>

What does the attribute means? Is line corresponding to the line number in the file? and what's start and end stands for?

Answer 1

I found the answers in the sbt plugin code itself coverage.scala#L159-L168

  def invokedStatements: Iterable[Statement] = statements.filter(_.count > 0)
  def invokedStatementCount = invokedStatements.size
  def statementCoverage: Double = if (statementCount == 0) 1 else invokedStatementCount / statementCount.toDouble
  def statementCoveragePercent = statementCoverage * 100
  def statementCoverageFormatted: String = twoFractionDigits(statementCoveragePercent)
  def branches: Iterable[Statement] = statements.filter(_.branch)
  def branchCount: Int = branches.size
  def branchCoveragePercent = branchCoverage * 100
  def invokedBranches: Iterable[Statement] = branches.filter(_.count > 0)
  def invokedBranchesCount = invokedBranches.size

I simply had to parse the XML while considering the snippet above to recalculate the counts (eg branches count vs covered).