From 9ecb076769a41a1b0c0abd51e223d21b52341189 Mon Sep 17 00:00:00 2001
From: Sylwester Lachiewicz <slachiewicz@apache.org>
Date: Sat, 22 Aug 2026 16:44:44 +0200
Subject: [PATCH] Add a jupiter-tests target to run JUnit 5 tests

The junit task cannot run Jupiter tests, so there is nowhere to put one
today. This adds a junitlauncher target beside the existing run and a
selector naming the JUnit 5 tests, used by both so the two runners cannot
pick up the same class.

UnicodeUtilTest moves across as the first one, to prove the target runs.

Reports go to their own directory; junitreport still aggregates only the
junit task's XML, so nothing about the existing reporting changes.
---
 build.xml                                     | 45 ++++++++++++++++++-
 .../tools/ant/util/UnicodeUtilTest.java       |  4 +-
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/build.xml b/build.xml
index 0f00e70612..1a904dd4e0 100644
--- a/build.xml
+++ b/build.xml
@@ -85,6 +85,7 @@
   <property name="build.junit.xml" location="${build.tests}/xml"/>
   <property name="build.junit.tmpdir" location="${build.tests}/tmp"/>
   <property name="build.junit.reports" location="${build.tests}/reports"/>
+  <property name="build.jupiter.xml" location="${build.tests}/jupiter-xml"/>
   <property name="build.pkg.dir" value="${build.dir}/pkg"/>
   <property name="antunit.xml" location="${build.dir}/antunit/xml"/>
   <property name="antunit.tmpdir" location="${build.dir}/antunit/tmp"/>
@@ -239,6 +240,14 @@
     </or>
   </selector>
 
+  <!-- Tests written against JUnit 5. Run by the jupiter-tests target; the junit
+       task cannot run them, so it excludes this same selector. -->
+  <selector id="jupiter.tests">
+    <or>
+      <filename name="${ant.package}/util/UnicodeUtilTest.*"/>
+    </or>
+  </selector>
+
   <selector id="needs.apache-regexp">
     <filename name="${regexp.package}/JakartaRegexp*"/>
   </selector>
@@ -1916,7 +1925,36 @@ ${antunit.reports}
     </junitreport>
   </target>
 
-  <target name="junit-tests" depends="junit-batch,graaljs-tests,junit-single-test"/>
+  <target name="junit-tests" depends="junit-batch,graaljs-tests,junit-single-test,jupiter-tests"/>
+
+  <target name="jupiter-tests" depends="compile-tests,test-init"
+          if="junit.engine.jupiter.present"
+          description="--> runs the JUnit 5 tests">
+    <!-- A report whose test class is gone would still be picked up by the concat below. -->
+    <delete dir="${build.jupiter.xml}"/>
+    <mkdir dir="${build.jupiter.xml}"/>
+
+    <junitlauncher printSummary="${junit.summary}" failureProperty="junit.failed">
+      <classpath refid="tests-runtime-classpath"/>
+      <testclasses outputdir="${build.jupiter.xml}">
+        <fileset dir="${build.tests}">
+          <selector refid="jupiter.tests"/>
+        </fileset>
+        <listener type="legacy-plain" sendSysOut="true"/>
+      </testclasses>
+    </junitlauncher>
+
+    <!-- legacy-plain writes to files only, so print the failing ones. The fileset
+         selects nothing when the run passed. -->
+    <concat>
+      <fileset dir="${build.jupiter.xml}" includes="TEST-*.txt">
+        <or>
+          <contains text="FAILED"/>
+          <contains text="Caused an ERROR"/>
+        </or>
+      </fileset>
+    </concat>
+  </target>
 
   <target name="graaljs-tests" depends="compile-tests,test-init"
           if="graaljs.present">
@@ -1983,6 +2021,11 @@ ${antunit.reports}
           <!-- JUnit 5 / junitlauncher tests that aren't meant to run by junit task -->
           <exclude name="${optional.package}/junitlauncher/"/>
 
+          <!-- JUnit 5 tests, run by the jupiter-tests target -->
+          <none>
+            <selector refid="jupiter.tests"/>
+          </none>
+
           <!-- interactive tests -->
           <exclude name="${taskdefs.package}/TestProcess.java"/>
           <exclude name="${optional.package}/splash/SplashScreenTest.java"/>
diff --git a/src/tests/junit/org/apache/tools/ant/util/UnicodeUtilTest.java b/src/tests/junit/org/apache/tools/ant/util/UnicodeUtilTest.java
index 59b9136629..a3d6beef64 100644
--- a/src/tests/junit/org/apache/tools/ant/util/UnicodeUtilTest.java
+++ b/src/tests/junit/org/apache/tools/ant/util/UnicodeUtilTest.java
@@ -17,9 +17,9 @@
  */
 package org.apache.tools.ant.util;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class UnicodeUtilTest {