From 3ab5040bc7828e000b7280263f53142c66ab6f1e Mon Sep 17 00:00:00 2001
From: Ethan Atkins <contact@ethanatkins.com>
Date: Thu, 3 Oct 2019 11:17:18 -0700
Subject: [PATCH] Clear supershell lines before suppressed task

I noticed that when entering the console, I'd often be left with a
supershell line at the bottom of the screen that would eventually get
interlaced with my console commands. This can be eliminated by clearing
the supershell progress before evaluating the task if it is one of the
skip tasks.
---
 .../scala/sbt/internal/TaskProgress.scala     | 20 ++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/main/src/main/scala/sbt/internal/TaskProgress.scala b/main/src/main/scala/sbt/internal/TaskProgress.scala
index 675e75f9c..93138ea2e 100644
--- a/main/src/main/scala/sbt/internal/TaskProgress.scala
+++ b/main/src/main/scala/sbt/internal/TaskProgress.scala
@@ -57,6 +57,10 @@ private[sbt] final class TaskProgress(log: ManagedLogger)
     ConsoleAppender.setTerminalWidth(JLine.terminal.getWidth)
   }
 
+  override def beforeWork(task: Task[_]): Unit = {
+    super.beforeWork(task)
+    if (containsSkipTasks(Vector(task)) || lastTaskCount.get == 0) report()
+  }
   override def afterReady(task: Task[_]): Unit = ()
 
   override def afterCompleted[A](task: Task[A], result: Result[A]): Unit = ()
@@ -76,10 +80,10 @@ private[sbt] final class TaskProgress(log: ManagedLogger)
     val currentTasks = activeTasks.toVector.filterNot(Def.isDummy)
     val ltc = lastTaskCount.get
     val currentTasksCount = currentTasks.size
-    def report0(): Unit = {
+    def report0(tasks: Vector[Task[_]]): Unit = {
       val event = ProgressEvent(
         "Info",
-        currentTasks
+        tasks
           .map { task =>
             val elapsed = timings.get(task).currentElapsedMicros
             ProgressItem(taskName(task), elapsed)
@@ -92,9 +96,15 @@ private[sbt] final class TaskProgress(log: ManagedLogger)
       import sbt.internal.util.codec.JsonProtocol._
       log.logEvent(Level.Info, event)
     }
-    if (containsSkipTasks(currentTasks)) ()
-    else report0()
-    lastTaskCount.set(currentTasksCount)
+    if (containsSkipTasks(currentTasks)) {
+      if (ltc > 0) {
+        lastTaskCount.set(0)
+        report0(Vector.empty)
+      }
+    } else {
+      lastTaskCount.set(currentTasksCount)
+      report0(currentTasks)
+    }
   }
 
   private[this] def containsSkipTasks(tasks: Vector[Task[_]]): Boolean = {