Remove PrintLogger (#4661)

Part of #3603

We've been using the new multi-line `PromptLogger` for a while since
0.12.0 was released back in Aug 2024, and it's worked great. So we can
remove the old implementation for 0.13.0 due in mid 2025, and deprecate
and hide the `--remove-prompt` flag that was introduced to flip back to
the old implementation.

It turns out that we were still using the old `PrintLogger` in a bunch
of places - unit tests, testrunner, etc. - and I had to replace those
use sites either with `PromptLogger` or with just `println`

Also made some adjustments to `enableTicker` handling to keep it
internal within `Logger` so it is more consistently applied, and fixed
the logging of skipped tasks in `--keep-going`

core/api/src/mill/api/Logger.scala

@@ -69,7 +69,7 @@ object Logger {
 
     def debugEnabled: Boolean
 
-    def enableTicker: Boolean
+    private[mill] def enableTicker: Boolean
 
     def infoColor: fansi.Attrs
 

core/exec/src/mill/exec/GroupExecution.scala

@@ -307,9 +307,9 @@ private trait GroupExecution {
     fileLoggerOpt.foreach(_.close())
 
     if (!failFast) maybeTargetLabel.foreach { targetLabel =>
-      val taskFailed = newResults.exists(task => !task._2.isInstanceOf[Success[?]])
+      val taskFailed = newResults.exists(task => task._2.isInstanceOf[ExecResult.Failing[?]])
       if (taskFailed) {
-        logger.error(s"[$counterMsg] $targetLabel failed")
+        logger.error(s"$targetLabel failed")
       }
     }
 

core/internal/src/mill/internal/PrefixLogger.scala

@@ -32,7 +32,8 @@ private[mill] class PrefixLogger(
 
   assert(key0.forall(_.nonEmpty))
   val linePrefix: String =
-    if (noPrefix || logPrefixKey.isEmpty) "" else s"[${logPrefixKey.mkString("-")}] "
+    if (noPrefix || logPrefixKey.isEmpty || !prompt.enableTicker) ""
+    else s"[${logPrefixKey.mkString("-")}] "
   override def toString: String =
     s"PrefixLogger($logger0, $key0)"
 

core/internal/src/mill/internal/PromptLogger.scala

@@ -305,15 +305,19 @@ private[mill] object PromptLogger {
           promptShown = false
         }
 
-        // Clear each line as they are drawn, rather than relying on clearing
-        // the entire screen before each batch of writes, to try and reduce the
-        // amount of terminal flickering in slow terminals (e.g. windows)
-        // https://stackoverflow.com/questions/71452837/how-to-reduce-flicker-in-terminal-re-drawing
-        dest.write(
-          new String(buf, 0, end)
-            .replaceAll("(\r\n|\n|\t)", AnsiNav.clearLine(0) + "$1")
-            .getBytes
-        )
+        if (enableTicker) {
+          // Clear each line as they are drawn, rather than relying on clearing
+          // the entire screen before each batch of writes, to try and reduce the
+          // amount of terminal flickering in slow terminals (e.g. windows)
+          // https://stackoverflow.com/questions/71452837/how-to-reduce-flicker-in-terminal-re-drawing
+          dest.write(
+            new String(buf, 0, end)
+              .replaceAll("(\r\n|\n|\t)", AnsiNav.clearLine(0) + "$1")
+              .getBytes
+          )
+        } else {
+          dest.write(new String(buf, 0, end).getBytes)
+        }
       }
     }
 

example/fundamentals/tasks/7-forking-futures/build.mill

@@ -29,10 +29,10 @@ def taskSpawningFutures = Task {
 /** Usage
 
 > ./mill show taskSpawningFutures
-[1] Running First Future inside .../out/taskSpawningFutures.dest/future-1
-[2] Running Second Future inside .../out/taskSpawningFutures.dest/future-2
-[1] Finished First Future
-[2] Finished Second Future
+Running First Future inside .../out/taskSpawningFutures.dest/future-1
+Running Second Future inside .../out/taskSpawningFutures.dest/future-2
+Finished First Future
+Finished Second Future
 3
 
 */

integration/feature/full-run-logs/src/FullRunLogsTests.scala

@@ -14,12 +14,13 @@ object FullRunLogsTests extends UtestIntegrationTestSuite {
       import tester._
 
       val res = eval(("--ticker", "false", "run", "--text", "hello"))
+
       res.isSuccess ==> true
       assert(res.out == "<h1>hello</h1>")
       assert(
         res.err.replace('\\', '/').replaceAll("(\r\n)|\r", "\n") ==
-          s"""[build.mill] [info] compiling 1 Scala source to ${tester.workspacePath}/out/mill-build/compile.dest/classes ...
-             |[build.mill] [info] done compiling
+          s"""[info] compiling 1 Scala source to ${tester.workspacePath}/out/mill-build/compile.dest/classes ...
+             |[info] done compiling
              |[info] compiling 1 Java source to ${tester.workspacePath}/out/compile.dest/classes ...
              |[info] done compiling""".stripMargin.replace('\\', '/').replaceAll("(\r\n)|\r", "\n")
       )
@@ -52,6 +53,36 @@ object FullRunLogsTests extends UtestIntegrationTestSuite {
       val normErr = res.err.replace('\\', '/').replaceAll("(\r\n)|\r", "\n")
       assert(expectedErrorRegex.r.matches(normErr))
     }
+    test("keepGoingFailure") - integrationTest { tester =>
+      import tester._
+
+      modifyFile(workspacePath / "src/foo/Foo.java", _ + "class Bar")
+      val res = eval(("--ticker", "true", "--keep-going", "jar"))
+      res.isSuccess ==> false
+
+      val expectedErrorRegex = java.util.regex.Pattern
+        .quote(
+          s"""<dashes> jar <dashes>
+             |[build.mill-<digits>/<digits>] compile
+             |[build.mill-<digits>] [info] compiling 1 Scala source to ${tester.workspacePath}/out/mill-build/compile.dest/classes ...
+             |[build.mill-<digits>] [info] done compiling
+             |[<digits>/<digits>] compile
+             |[<digits>] [info] compiling 1 Java source to ${tester.workspacePath}/out/compile.dest/classes ...
+             |[<digits>] [error] ${tester.workspacePath}/src/foo/Foo.java:36:10: reached end of file while parsing
+             |[<digits>] compile failed
+             |[<digits>/<digits>, 1 failed] <dashes> jar <dashes> <digits>s
+             |1 tasks failed
+             |compile javac returned non-zero exit code"""
+            .stripMargin
+            .replaceAll("(\r\n)|\r", "\n")
+            .replace('\\', '/')
+        )
+        .replace("<digits>", "\\E\\d+\\Q")
+        .replace("<dashes>", "\\E=+\\Q")
+
+      val normErr = res.err.replace('\\', '/').replaceAll("(\r\n)|\r", "\n")
+      assert(expectedErrorRegex.r.matches(normErr))
+    }
     test("show") - integrationTest { tester =>
       import tester._
       // Make sure when we have nested evaluations, e.g. due to usage of evaluator commands
@@ -74,58 +105,5 @@ object FullRunLogsTests extends UtestIntegrationTestSuite {
       assert(millProfile.exists(_.obj("label").str == "show"))
       assert(millChromeProfile.exists(_.obj("name").str == "show"))
     }
-    test("failedTasksCounter") - integrationTest { tester =>
-      import tester._
-
-      val javaSource = os.Path(workspacePath, os.pwd)
-      val fooJava = javaSource / "src" / "foo" / "Foo.java"
-      val originalContent = os.read(fooJava)
-
-      // Introduce a compilation error by adding an unclosed brace
-      modifyFile(fooJava, _.replace("class Foo", "class Foo {"))
-
-      // Run with ticker to see the failed tasks count for compile
-      val compileRes = eval(("--ticker", "true", "compile"))
-      compileRes.isSuccess ==> false
-
-      // Verify the output shows failed tasks count in the progress indicator
-      val failedPattern = "\\[(\\d+)/(\\d+),\\s*(\\d+)\\s*failed\\]".r // Matches [X/Y, N failed]
-      val failedMatch = failedPattern.findFirstIn(compileRes.err)
-      failedMatch.isDefined ==> true
-
-      // Extract and verify the number of failed tasks
-      val failedCount =
-        failedPattern.findFirstMatchIn(compileRes.err).map(_.group(3).toInt).getOrElse(0)
-      failedCount ==> 1 // Expecting 1 failed task for compile
-
-      // Run jar task with --keep-going to see upstream failures
-      val jarKeepGoingRes = eval(("--ticker", "true", "--keep-going", "jar"))
-      jarKeepGoingRes.isSuccess ==> false
-
-      // Verify the output shows failed tasks count in the progress indicator
-      val jarKeepGoingFailedMatch = failedPattern.findFirstIn(jarKeepGoingRes.err)
-      jarKeepGoingFailedMatch.isDefined ==> true
-
-      // Extract and verify the number of failed tasks
-      val jarKeepGoingFailedCount =
-        failedPattern.findFirstMatchIn(jarKeepGoingRes.err).map(_.group(3).toInt).getOrElse(0)
-      jarKeepGoingFailedCount ==> 1 // Expecting 1 failed task for jar with --keep-going
-
-      // Run jar task without --keep-going to see it fail immediately
-      val jarRes = eval(("--ticker", "true", "jar"))
-      jarRes.isSuccess ==> false
-
-      // Verify the output shows failed tasks count in the progress indicator
-      val jarFailedMatch = failedPattern.findFirstIn(jarRes.err)
-      jarFailedMatch.isDefined ==> true
-
-      // Extract and verify the number of failed tasks
-      val jarFailedCount =
-        failedPattern.findFirstMatchIn(jarRes.err).map(_.group(3).toInt).getOrElse(0)
-      jarFailedCount ==> 1 // Expecting 1 failed task for jar without --keep-going
-
-      // Restore the original content
-      modifyFile(fooJava, _ => originalContent)
-    }
   }
 }

runner/src/mill/runner/MillCliConfig.scala

@@ -126,11 +126,13 @@ case class MillCliConfig(
     metaLevel: Option[Int] = None,
     @arg(doc = "Allows command args to be passed positionally without `--arg` by default")
     allowPositional: Flag = Flag(),
+    @deprecated("No longer used", "Mill 0.13.0")
     @arg(
       doc = """
         Disables the new multi-line status prompt used for showing thread
         status at the command line and falls back to the legacy ticker
-      """
+      """,
+      hidden = true
     )
     disablePrompt: Flag = Flag(),
     @arg(

runner/src/mill/runner/MillMain.scala

@@ -14,7 +14,7 @@ import mill.constants.{OutFiles, ServerFiles, Util}
 import mill.client.lock.Lock
 import mill.main.BuildInfo
 import mill.runner.worker.ScalaCompilerWorker
-import mill.internal.{Colors, PrintLogger, PromptLogger}
+import mill.internal.{Colors, PromptLogger}
 
 import java.lang.reflect.InvocationTargetException
 import scala.util.control.NonFatal
@@ -121,7 +121,6 @@ object MillMain {
       systemExit: Int => Nothing,
       serverDir: os.Path
   ): (Boolean, RunnerState) = {
-    val printLoggerState = new PrintLogger.State()
     val streams = streams0
     SystemStreams.withStreams(streams) {
       os.SubProcess.env.withValue(env) {
@@ -261,12 +260,10 @@ object MillMain {
                             Using.resource(getLogger(
                               streams,
                               config,
-                              mainInteractive,
                               enableTicker =
                                 config.ticker
                                   .orElse(config.enableTicker)
                                   .orElse(Option.when(config.disableTicker.value)(false)),
-                              printLoggerState,
                               serverDir,
                               colored = colored,
                               colors = colors
@@ -366,40 +363,22 @@ object MillMain {
   def getLogger(
       streams: SystemStreams,
       config: MillCliConfig,
-      mainInteractive: Boolean,
       enableTicker: Option[Boolean],
-      printLoggerState: PrintLogger.State,
       serverDir: os.Path,
       colored: Boolean,
       colors: Colors
   ): Logger with AutoCloseable = {
-
-    val logger = if (config.disablePrompt.value) {
-      new mill.internal.PrintLogger(
-        colored = colored,
-        enableTicker = enableTicker.getOrElse(mainInteractive),
-        infoColor = colors.info,
-        errorColor = colors.error,
-        streams = streams,
-        debugEnabled = config.debugLog.value,
-        context = "",
-        printLoggerState
-      )
-    } else {
-      new PromptLogger(
-        colored = colored,
-        enableTicker = enableTicker.getOrElse(true),
-        infoColor = colors.info,
-        errorColor = colors.error,
-        systemStreams0 = streams,
-        debugEnabled = config.debugLog.value,
-        titleText = config.leftoverArgs.value.mkString(" "),
-        terminfoPath = serverDir / ServerFiles.terminfo,
-        currentTimeMillis = () => System.currentTimeMillis()
-      )
-    }
-
-    logger
+    new PromptLogger(
+      colored = colored,
+      enableTicker = enableTicker.getOrElse(true),
+      infoColor = colors.info,
+      errorColor = colors.error,
+      systemStreams0 = streams,
+      debugEnabled = config.debugLog.value,
+      titleText = config.leftoverArgs.value.mkString(" "),
+      terminfoPath = serverDir / ServerFiles.terminfo,
+      currentTimeMillis = () => System.currentTimeMillis()
+    )
   }
 
   /**