diff --git a/main-actions/src/main/scala/sbt/TestResultLogger.scala b/main-actions/src/main/scala/sbt/TestResultLogger.scala
index 6d523ea75..5ab02d6c0 100644
--- a/main-actions/src/main/scala/sbt/TestResultLogger.scala
+++ b/main-actions/src/main/scala/sbt/TestResultLogger.scala
@@ -106,10 +106,9 @@ object TestResultLogger {
         else
           run(printFailures)
 
-        results.overall match {
+        results.overall match
           case TestResult.Error | TestResult.Failed => throw new TestsFailedException
-          case TestResult.Passed                    =>
-        }
+          case TestResult.Empty | TestResult.Passed => ()
       }
     }
 
@@ -164,11 +163,11 @@ object TestResultLogger {
       val extra = otherCounts.withFilter(_._2 > 0).map { (label, count) => s", $label $count" }
 
       val postfix = base + extra.mkString
-      results.overall match {
+      results.overall match
+        case TestResult.Empty  => ()
         case TestResult.Error  => log.error("Error: " + postfix)
         case TestResult.Passed => log.info("Passed: " + postfix)
         case TestResult.Failed => log.error("Failed: " + postfix)
-      }
     })
 
     val printFailures = TestResultLogger((log, results, _) => {
diff --git a/main-actions/src/main/scala/sbt/Tests.scala b/main-actions/src/main/scala/sbt/Tests.scala
index ec977e6aa..61dda1875 100644
--- a/main-actions/src/main/scala/sbt/Tests.scala
+++ b/main-actions/src/main/scala/sbt/Tests.scala
@@ -50,7 +50,7 @@ object Tests {
    * @param events The result of each test group (suite) executed during this test run.
    * @param summaries Explicit summaries directly provided by test frameworks.  This may be empty, in which case a default summary will be generated.
    */
-  final case class Output(
+  private[sbt] final case class Output(
       overall: TestResult,
       events: Map[String, SuiteResult],
       summaries: Iterable[Summary]
@@ -458,11 +458,10 @@ object Tests {
     Output(overall(results.map(_._2.result)), results.toMap, Iterable.empty)
 
   private def severity(r: TestResult): Int =
-    r match {
-      case TestResult.Passed => 0
-      case TestResult.Failed => 1
-      case TestResult.Error  => 2
-    }
+    r match
+      case TestResult.Passed | TestResult.Empty => 0
+      case TestResult.Failed                    => 1
+      case TestResult.Error                     => 2
 
   def foldTasks(results: Seq[Task[Output]], parallel: Boolean): Task[Output] =
     if (results.isEmpty) {
diff --git a/main-settings/src/main/scala/sbt/SlashSyntax.scala b/main-settings/src/main/scala/sbt/SlashSyntax.scala
index f577fd5bc..d7facacec 100644
--- a/main-settings/src/main/scala/sbt/SlashSyntax.scala
+++ b/main-settings/src/main/scala/sbt/SlashSyntax.scala
@@ -19,7 +19,7 @@ import sbt.Scope.RefThenConfig.{ project, config }
  *
  * @example
  *  {{{
- *  Test / test := ()
+ *  Test / test := TestResult.Empty
  *  console.key / scalacOptions += "-deprecation"
  *  Compile / console / scalacOptions += "-Ywarn-numeric-widen"
  *  }}}
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index a5368b335..09943ddac 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -76,6 +76,7 @@ import sbt.nio.Keys.*
 import sbt.nio.file.syntax.*
 import sbt.nio.file.{ FileTreeView, Glob, RecursiveGlob }
 import sbt.nio.Watch
+import sbt.protocol.testing.TestResult
 import sbt.std.TaskExtra.*
 import sbt.testing.{ AnnotatedFingerprint, Framework, Runner, SubclassFingerprint }
 import sbt.util.CacheImplicits.given
@@ -1155,7 +1156,10 @@ object Defaults extends BuildCommon {
     testFull := Def.uncached {
       val trl = (Test / testFull / testResultLogger).value
       val taskName = Project.showContextKey(state.value).show(resolvedScoped.value)
-      try trl.run(streams.value.log, executeTests.value, taskName)
+      try
+        val output = executeTests.value
+        trl.run(streams.value.log, output, taskName)
+        output.overall
       finally close(testLoader.value)
     },
     testOnly := {
@@ -1287,10 +1291,10 @@ object Defaults extends BuildCommon {
     }
 
   @nowarn
-  def inputTests(key: InputKey[?]): Initialize[InputTask[Unit]] =
+  def inputTests(key: InputKey[?]): Initialize[InputTask[TestResult]] =
     inputTests0.mapReferenced(Def.mapScope((s) => s.rescope(key.key)))
 
-  private lazy val inputTests0: Initialize[InputTask[Unit]] = {
+  private lazy val inputTests0: Initialize[InputTask[TestResult]] = {
     val parser = loadForParser(definedTestNames)((s, i) => testOnlyParser(s, i getOrElse Nil))
     ParserGen(parser).flatMapTask { (selected, frameworkOptions) =>
       val s = streams.value
@@ -1318,7 +1322,9 @@ object Defaults extends BuildCommon {
       val trl = testResultLogger.value
       (Def
         .value[Task[Tests.Output]] { output })
-        .map { out => trl.run(s.log, out, taskName) }
+        .map: out =>
+          trl.run(s.log, out, taskName)
+          out.overall
     }
   }
 
diff --git a/main/src/main/scala/sbt/Keys.scala b/main/src/main/scala/sbt/Keys.scala
index 02a5c2a56..950cc12ee 100644
--- a/main/src/main/scala/sbt/Keys.scala
+++ b/main/src/main/scala/sbt/Keys.scala
@@ -35,6 +35,7 @@ import sbt.librarymanagement.LibraryManagementCodec.*
 import sbt.librarymanagement.*
 import sbt.librarymanagement.ivy.{ Credentials, IvyConfiguration, IvyPaths, UpdateOptions }
 import sbt.nio.file.Glob
+import sbt.protocol.testing.TestResult
 import sbt.testing.Framework
 import sbt.util.{ cacheLevel, ActionCacheStore, Digest, Level, Logger, LoggerContext }
 import xsbti.{ HashedVirtualFileRef, VirtualFile, VirtualFileRef }
@@ -357,10 +358,10 @@ object Keys {
   val definedTestNames = taskKey[Seq[String]]("Provides the set of defined test names.").withRank(BMinusTask)
   val definedTestDigests = taskKey[Map[String, Digest]]("Provides a unique digest of defined tests.").withRank(DTask)
   val executeTests = taskKey[Tests.Output]("Executes all tests, producing a report.").withRank(CTask)
-  val test = inputKey[Unit]("Executes the tests that either failed before, were not run or whose transitive dependencies changed, among those provided as arguments.").withRank(ATask)
-  val testFull = taskKey[Unit]("Executes all tests.").withRank(APlusTask)
-  val testOnly = inputKey[Unit]("Executes the tests provided as arguments or all tests if no arguments are provided.").withRank(ATask)
-  val testQuick = inputKey[Unit]("Alias for test.").withRank(CTask)
+  val test = inputKey[TestResult]("Executes the tests that either failed before, were not run or whose transitive dependencies changed, among those provided as arguments.").withRank(ATask)
+  val testFull = taskKey[TestResult]("Executes all tests.").withRank(APlusTask)
+  val testOnly = inputKey[TestResult]("Executes the tests provided as arguments or all tests if no arguments are provided.").withRank(ATask)
+  val testQuick = inputKey[TestResult]("Alias for test.").withRank(CTask)
   @cacheLevel(include = Array.empty)
   val testOptions = taskKey[Seq[TestOption]]("Options for running tests.").withRank(BPlusTask)
   private[sbt] val testOptionDigests = taskKey[Seq[Digest]]("Digest for testOptions").withRank(DTask)
diff --git a/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala b/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
index dd606137e..c33d25e6d 100644
--- a/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
+++ b/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
@@ -938,7 +938,9 @@ object BuildServerProtocol {
             item.classes.toList match {
               case Nil => Def.task(())
               case classes =>
-                (scope / testOnly).toTask(" " + classes.mkString(" "))
+                (scope / testOnly)
+                  .toTask(" " + classes.mkString(" "))
+                  .map(r => ())
             }
           }
           testTasks.joinWith(ts => TaskExtra.joinTasks(ts).join).result
@@ -952,7 +954,7 @@ object BuildServerProtocol {
         case None =>
           // run allTests in testParams.targets
           val filter = ScopeFilter.in(testParams.targets.map(workspace.scopes))
-          test.toTask("").all(filter).result
+          test.toTask("").map(r => ()).all(filter).result
       }
 
       Def.task {
diff --git a/sbt-app/src/sbt-test/actions/cross-advanced/build.sbt b/sbt-app/src/sbt-test/actions/cross-advanced/build.sbt
index e88a82cba..36919cf4a 100644
--- a/sbt-app/src/sbt-test/actions/cross-advanced/build.sbt
+++ b/sbt-app/src/sbt-test/actions/cross-advanced/build.sbt
@@ -26,7 +26,7 @@ lazy val foo = project
       // This tests that +testOnly will respect bar's crossScalaVersions and not switch
       val x = (LocalProject("bar") / scalaVersion).value
       assert(x == scala212, s"$x == $scala212")
-      val _ = (Test / testOnly).evaluated
+      (Test / testOnly).evaluated
     },
     compile2 := Def.uncached {
       // This tests that +build will ignore bar's crossScalaVersions and use root's like sbt 0.13
diff --git a/sbt-app/src/sbt-test/classloader-cache/jni/build.sbt b/sbt-app/src/sbt-test/classloader-cache/jni/build.sbt
index 1508b62a5..07a882033 100644
--- a/sbt-app/src/sbt-test/classloader-cache/jni/build.sbt
+++ b/sbt-app/src/sbt-test/classloader-cache/jni/build.sbt
@@ -5,7 +5,7 @@ val copyTestResources = inputKey[Unit]("Copy the native libraries to the base di
 val appendToLibraryPath = taskKey[Unit]("Append the base directory to the java.library.path system property")
 val dropLibraryPath = taskKey[Unit]("Drop the last path from the java.library.path system property")
 val wrappedRun = taskKey[Unit]("Run with modified java.library.path")
-val wrappedTest = taskKey[Unit]("Test with modified java.library.path")
+val wrappedTest = taskKey[TestResult]("Test with modified java.library.path")
 
 def wrap[A1](task: InputKey[A1]): Def.Initialize[Task[Unit]] =
   Def.sequential(appendToLibraryPath, task.toTask(""), dropLibraryPath)
@@ -39,5 +39,8 @@ val root = (project in file(".")).settings(
     ()
   },
   wrappedRun := wrap(Runtime / run).value,
-  wrappedTest := wrap(Test / testOnly).value
+  wrappedTest := Def.uncached {
+    wrap(Test / testOnly).value
+    TestResult.Passed
+  }
 )
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestResult.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestResult.scala
index 024b495b2..334e85986 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestResult.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestResult.scala
@@ -9,6 +9,7 @@ sealed abstract class TestResult extends Serializable
 object TestResult {
   
   
+  case object Empty extends TestResult
   case object Passed extends TestResult
   case object Failed extends TestResult
   case object Error extends TestResult
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/codec/TestResultFormats.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/codec/TestResultFormats.scala
index 960fb49d1..e1c2fc270 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/codec/TestResultFormats.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/codec/TestResultFormats.scala
@@ -11,6 +11,7 @@ implicit lazy val TestResultFormat: JsonFormat[sbt.protocol.testing.TestResult]
     __jsOpt match {
       case Some(__js) =>
       unbuilder.readString(__js) match {
+        case "Empty" => sbt.protocol.testing.TestResult.Empty
         case "Passed" => sbt.protocol.testing.TestResult.Passed
         case "Failed" => sbt.protocol.testing.TestResult.Failed
         case "Error" => sbt.protocol.testing.TestResult.Error
@@ -21,6 +22,7 @@ implicit lazy val TestResultFormat: JsonFormat[sbt.protocol.testing.TestResult]
   }
   override def write[J](obj: sbt.protocol.testing.TestResult, builder: Builder[J]): Unit = {
     val str = obj match {
+      case sbt.protocol.testing.TestResult.Empty => "Empty"
       case sbt.protocol.testing.TestResult.Passed => "Passed"
       case sbt.protocol.testing.TestResult.Failed => "Failed"
       case sbt.protocol.testing.TestResult.Error => "Error"
diff --git a/testing/src/main/contraband/testing.contra b/testing/src/main/contraband/testing.contra
index 94cb92425..b6de3bfec 100644
--- a/testing/src/main/contraband/testing.contra
+++ b/testing/src/main/contraband/testing.contra
@@ -59,6 +59,7 @@ type TestItemDetail {
 
 ## Testing result
 enum TestResult {
+  Empty
   Passed
   Failed
   Error
diff --git a/testing/src/main/scala/sbt/TestReportListener.scala b/testing/src/main/scala/sbt/TestReportListener.scala
index 35c6f67d4..2b5a9ee60 100644
--- a/testing/src/main/scala/sbt/TestReportListener.scala
+++ b/testing/src/main/scala/sbt/TestReportListener.scala
@@ -45,7 +45,7 @@ trait TestsListener extends TestReportListener {
 /**
  * Provides the overall `result` of a group of tests (a suite) and test counts for each result type.
  */
-final class SuiteResult(
+private[sbt] final class SuiteResult(
     val result: TestResult,
     val passedCount: Int,
     val failureCount: Int,
@@ -99,7 +99,7 @@ final class SuiteResult(
   }
 }
 
-object SuiteResult {
+private[sbt] object SuiteResult {
 
   /**
    * Computes the overall result and counts for a suite with individual test results in `events`.