Add a script for adapting Mill test output into JUnit XML format

.github/scripts/generate-junit-reports.sc

@@ -0,0 +1,131 @@
+#!/usr/bin/env -S scala-cli shebang
+//> using scala 3
+//> using toolkit 0.2.1
+//> using dep org.scala-lang.modules::scala-xml:2.2.0
+// adapted from https://github.com/vic/mill-test-junit-report
+import java.io.File
+import scala.collection.mutable.ArrayBuffer
+import scala.annotation.tailrec
+import java.nio.file.Paths
+
+case class Trace(declaringClass: String, methodName: String, fileName: String, lineNumber: Int) {
+  override def toString: String = s"$declaringClass.$methodName($fileName:$lineNumber)"
+}
+
+case class Failure(name: String, message: String, trace: Seq[Trace])
+
+case class Test(
+  fullyQualifiedName: String,
+  selector: String,
+  duration: Double,
+  failure: Option[Failure]
+)
+
+@tailrec
+def findFiles(paths: Seq[os.Path], result: Seq[os.Path] = Nil): Seq[os.Path] =
+  paths match
+    case Nil => result
+    case head :: tail =>
+      val newFiles =
+        if head.last == "test.dest" && os.isDir(head) then
+          os.list(head).filter(f => f.last == "out.json").toList
+        else Seq.empty
+      val newDirs = os.list(head).filter(p => os.isDir(p)).toList
+      findFiles(tail ++ newDirs, result ++ newFiles)
+
+extension (s: String)
+  def toNormalisedPath: os.Path = if Paths.get(s).isAbsolute then os.Path(s) else os.Path(s, os.pwd)
+
+def printUsageMessage(): Unit = println("Usage: generate-junit-reports <id> <name> <into> <path>")
+if args.length != 4 then {
+  println(s"Error: provided too few arguments: ${args.length}")
+  printUsageMessage()
+  System.exit(1)
+}
+
+val id: String   = args(0)
+val name: String = args(1)
+
+if new File(args(2)).exists() then {
+  println(s"Error: specified output path already exists: ${args(2)}")
+  System.exit(1)
+}
+val into = args(2).toNormalisedPath
+
+val pathArg = args(3)
+val rootPath: os.Path =
+  if Paths.get(pathArg).isAbsolute then os.Path(pathArg) else os.Path(pathArg, os.pwd)
+if !os.isDir(rootPath) then {
+  println(s"The path provided is not a directory: $pathArg")
+  System.exit(1)
+}
+val reports: Seq[os.Path] = findFiles(Seq(rootPath))
+println(s"Found ${reports.length} mill json reports:")
+println(reports.mkString("\n"))
+println("Reading reports...")
+val tests: Seq[Test] = reports.map(x => ujson.read(x.toNIO)).flatMap { json =>
+  json(1).value.asInstanceOf[ArrayBuffer[ujson.Obj]].map { test =>
+    Test(
+      fullyQualifiedName = test("fullyQualifiedName").str,
+      selector = test("selector").str,
+      duration = test("duration").num / 1000.0,
+      failure = test("status").str match {
+        case "Failure" => Some(Failure(
+            name = test("exceptionName")(0).str,
+            message = test("exceptionMsg")(0).str,
+            trace = test("exceptionTrace")(0).arr.map { st =>
+              val declaringClass = st("declaringClass").str
+              val methodName     = st("methodName").str
+              val fileName       = st("fileName")(0).str
+              val lineNumber     = st("lineNumber").num.toInt
+              Trace(declaringClass, methodName, fileName, lineNumber)
+            }.toList
+          ))
+        case _ => None
+      }
+    )
+  }
+}
+println(s"Found ${tests.length} tests.")
+println("Generating JUnit XML report...")
+val suites = tests.groupBy(_.fullyQualifiedName).map { case (suit, tests) =>
+  val testcases = tests.map { test =>
+    <testcase id={test.selector} classname={test.fullyQualifiedName} name={
+      test.selector.substring(test.fullyQualifiedName.length)
+    } time={test.duration.toString}>
+        {
+      test.failure.map { failure =>
+        <failure message={failure.message} type="ERROR">
+            ERROR: {failure.message}
+            Category: {failure.name}
+            File: {failure.trace(1).fileName}
+            Line: {failure.trace(1).lineNumber}
+          </failure>
+      }.orNull
+    }
+        {
+      test.failure.map { failure =>
+        <system-err>{
+          failure.trace.mkString(s"${failure.name}: ${failure.message}", "\n    at ", "")
+        }</system-err>
+      }.orNull
+    }
+      </testcase>
+  }
+
+  <testsuite id={suit} name={suit} tests={tests.length.toString} failures={
+    tests.count(_.failure.isDefined).toString
+  } time={tests.map(_.duration).sum.toString}>
+      {testcases}
+    </testsuite>
+}
+
+val n = <testsuites id={id} name={name} tests={tests.length.toString} failures={
+  tests.count(_.failure.isDefined).toString
+} time={tests.map(_.duration).sum.toString}>
+  {suites}
+</testsuites>
+val prettyXmlPrinter = new scala.xml.PrettyPrinter(80, 2)
+val xmlToSave        = scala.xml.XML.loadString(prettyXmlPrinter.format(n))
+scala.xml.XML.save(filename = into.toString(), node = xmlToSave, xmlDecl = true)
+println(s"Generated report at: $into")