Try to fix & clean up VirtualThreadsDebugViewTests

+ add java23 to build.properties to fix failures on the build server
+ change explicit (duplicate) creation to the normal style 'assert...'
+ allow running it on 23+

org.eclipse.jdt.debug.tests/build.properties

@@ -26,6 +26,7 @@ bin.includes = plugin.xml,\
                java8/,\
                java9/,\
                java16_/,\
+               java23/,\
                java24/
 source.javadebugtests.jar = test plugin/,\
                             tests/,\

org.eclipse.jdt.debug.tests/test plugin/org/eclipse/jdt/debug/testplugin/JavaProjectHelper.java

@@ -189,6 +189,15 @@ public static boolean isJava21_Compatible() {
 		return isCompatible(21);
 	}
 
+	/**
+	 * Returns if the currently running VM is version compatible with Java 23
+	 *
+	 * @return <code>true</code> if a Java 23 (or greater) VM is running <code>false</code> otherwise
+	 */
+	public static boolean isJava23_Compatible() {
+		return isCompatible(23);
+	}
+
 	/**
 	 * Returns if the currently running VM is version compatible with Java 24
 	 *

org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java

@@ -245,6 +245,7 @@ public abstract class AbstractDebugTest extends TestCase implements  IEvaluation
 	private static boolean loaded9 = false;
 	private static boolean loaded16_ = false;
 	private static boolean loaded21 = false;
+	private static boolean loaded23 = false;
 	private static boolean loaded24 = false;
 	private static boolean loadedEE = false;
 	private static boolean loadedJRE = false;
@@ -626,6 +627,34 @@ synchronized void assert21Project() {
 		}
 	}
 
+	synchronized void assert23Project() {
+		IJavaProject jp = null;
+		ArrayList<ILaunchConfiguration> cfgs = new ArrayList<>(1);
+		try {
+			if (!loaded23) {
+				jp = createProject(TWENTYTHREE_PROJECT_NAME, JavaProjectHelper.TEST_23_SRC_DIR.toString(), JavaProjectHelper.JAVA_SE_23_EE_NAME, false);
+				jp.setOption(JavaCore.COMPILER_SOURCE, JavaCore.VERSION_23);
+				jp.setOption(JavaCore.COMPILER_COMPLIANCE, JavaCore.VERSION_23);
+				cfgs.add(createLaunchConfiguration(jp, "Main21"));
+				loaded23 = true;
+				waitForBuild();
+				assertNoErrorMarkersExist(jp.getProject());
+			}
+		} catch (Exception e) {
+			try {
+				if (jp != null) {
+					jp.getProject().delete(true, true, null);
+					for (int i = 0; i < cfgs.size(); i++) {
+						cfgs.get(i).delete();
+					}
+				}
+			} catch (CoreException ce) {
+				// ignore
+			}
+			handleProjectCreationException(e, TWENTYTHREE_PROJECT_NAME, jp);
+		}
+	}
+
 	/**
 	 * Creates the Java 24 compliant project
 	 */
@@ -957,6 +986,16 @@ protected IJavaProject get21Project() {
 		return getJavaProject(TWENTYONE_PROJECT_NAME);
 	}
 
+	/**
+	 * Returns the 'Two_Three' project, used for Java 23 tests.
+	 *
+	 * @return the test project
+	 */
+	protected IJavaProject get23Project() {
+		assert23Project();
+		return getJavaProject(TWENTYTHREE_PROJECT_NAME);
+	}
+
 	/**
 	 * Returns the 'Two_Four' project, used for Java 24 tests.
 	 *

org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AutomatedSuite.java

@@ -420,7 +420,7 @@ public AutomatedSuite() {
 		if (JavaProjectHelper.isJava16_Compatible()) {
 			addTest(new TestSuite(RecordBreakpointTests.class));
 		}
-		if (Runtime.version().feature() == 24 && JavaProjectHelper.isJava24_Compatible()) {
+		if (JavaProjectHelper.isJava23_Compatible()) {
 			addTest(new TestSuite(VirtualThreadsDebugViewTests.class));
 		}
 	}

org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/ui/VirtualThreadsDebugViewTests.java

@@ -17,12 +17,8 @@
  *******************************************************************************/
 package org.eclipse.jdt.debug.tests.ui;
 
-import java.util.ArrayList;
-
 import org.eclipse.core.resources.IFile;
-import org.eclipse.core.runtime.CoreException;
 import org.eclipse.debug.core.DebugPlugin;
-import org.eclipse.debug.core.ILaunchConfiguration;
 import org.eclipse.debug.core.model.IStackFrame;
 import org.eclipse.debug.core.model.IThread;
 import org.eclipse.debug.internal.ui.views.console.ProcessConsole;
@@ -31,10 +27,8 @@
 import org.eclipse.debug.ui.IDebugUIConstants;
 import org.eclipse.debug.ui.IDebugView;
 import org.eclipse.jdt.core.IJavaProject;
-import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.debug.core.IJavaBreakpoint;
 import org.eclipse.jdt.debug.core.IJavaThread;
-import org.eclipse.jdt.debug.testplugin.JavaProjectHelper;
 import org.eclipse.jdt.debug.tests.TestUtil;
 import org.eclipse.jdt.debug.ui.IJavaDebugUIConstants;
 import org.eclipse.jdt.internal.debug.core.model.JDIThread;
@@ -86,33 +80,7 @@ protected void tearDown() throws Exception {
 
 	@Override
 	protected IJavaProject getProjectContext() {
-		create23Project();
-		return getJavaProject(TWENTYTHREE_PROJECT_NAME);
-	}
-
-	synchronized void create23Project() {
-		IJavaProject jp = null;
-		ArrayList<ILaunchConfiguration> cfgs = new ArrayList<>(1);
-		try {
-			jp = createProject(TWENTYTHREE_PROJECT_NAME, JavaProjectHelper.TEST_23_SRC_DIR.toString(), JavaProjectHelper.JAVA_SE_23_EE_NAME, false);
-			jp.setOption(JavaCore.COMPILER_SOURCE, JavaCore.VERSION_23);
-			jp.setOption(JavaCore.COMPILER_COMPLIANCE, JavaCore.VERSION_23);
-			cfgs.add(createLaunchConfiguration(jp, "Main21"));
-			waitForBuild();
-			assertNoErrorMarkersExist(jp.getProject());
-		} catch (Exception e) {
-			try {
-				if (jp != null) {
-					jp.getProject().delete(true, true, null);
-					for (int i = 0; i < cfgs.size(); i++) {
-						cfgs.get(i).delete();
-					}
-				}
-			} catch (CoreException ce) {
-				// ignore
-			}
-			super.handleProjectCreationException(e, TWENTYTHREE_PROJECT_NAME, jp);
-		}
+		return get23Project();
 	}
 
 	public void testVirtualThreadDebugView() throws Exception {