LeftPad testForkGrouping sub-keys to ensure they're probably sortable…

… and greppable (#3653)
com-lihaoyi · Oct 3, 2024 · c8eddd7 · c8eddd7
1 parent d85dd40
commit c8eddd7
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Showing 3 changed files with 14 additions and 8 deletions.
diff --git a/main/eval/src/mill/eval/EvaluatorCore.scala b/main/eval/src/mill/eval/EvaluatorCore.scala
@@ -104,12 +104,11 @@ private[mill] trait EvaluatorCore extends GroupEvaluator {
       for (terminal <- terminals) {
         val deps = interGroupDeps(terminal)
         futures(terminal) = Future.sequence(deps.map(futures)).map { upstreamValues =>
-          val countMsg = count
-            .getAndIncrement()
-            .toString
-            .reverse
-            .padTo(terminals.size.toString.length, '0')
-            .reverse
+          val countMsg = mill.util.Util.leftPad(
+            count.getAndIncrement().toString,
+            terminals.length.toString.length,
+            '0'
+          )
 
           val verboseKeySuffix = s"/${terminals0.size}"
           logger.setPromptLeftHeader(s"$countMsg$verboseKeySuffix")

diff --git a/main/util/src/mill/util/Util.scala b/main/util/src/mill/util/Util.scala
@@ -101,4 +101,8 @@ object Util {
   def millProperty(key: String): Option[String] =
     Option(sys.props(key)) // System property has priority
       .orElse(Option(LongMillProps.getProperty(key)))
+
+  def leftPad(s: String, targetLength: Int, char: Char): String = {
+    char.toString * (targetLength - s.length) + s
+  }
 }
diff --git a/scalalib/src/mill/scalalib/TestModuleUtil.scala b/scalalib/src/mill/scalalib/TestModuleUtil.scala
@@ -122,19 +122,22 @@ private[scalalib] object TestModuleUtil {
       case Nil => runTestRunnerSubprocess(Nil, T.dest)
       case Seq(singleTestClassList) => runTestRunnerSubprocess(singleTestClassList, T.dest)
       case multipleTestClassLists =>
+        val maxLength = multipleTestClassLists.length.toString.length
         val futures = multipleTestClassLists.zipWithIndex.map { case (testClassList, i) =>
           val groupPromptMessage = testClassList match {
             case Seq(single) => single
             case multiple =>
               collapseTestClassNames(multiple).mkString(", ") + s", ${multiple.length} suites"
           }
 
+          val paddedIndex = mill.util.Util.leftPad(i.toString, maxLength, '0')
           val folderName = testClassList match {
             case Seq(single) => single
-            case multiple => s"group-$i-${multiple.head}"
+            case multiple =>
+              s"group-$paddedIndex-${multiple.head}"
           }
 
-          T.fork.async(T.dest / folderName, "" + i, groupPromptMessage) {
+          T.fork.async(T.dest / folderName, paddedIndex, groupPromptMessage) {
             (folderName, runTestRunnerSubprocess(testClassList, T.dest / folderName))
           }
         }