CompilationUnit does not contains modifier for the ImplicitTypeDeclaration

org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/ASTConverter_24Test.java

@@ -0,0 +1,92 @@
+/*******************************************************************************
+ * Copyright (c) 2025 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.core.tests.dom;
+
+import java.util.HashMap;
+import java.util.Map;
+import junit.framework.Test;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.jdt.core.ICompilationUnit;
+import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.jdt.core.dom.AST;
+import org.eclipse.jdt.core.dom.ASTParser;
+import org.eclipse.jdt.core.dom.CompilationUnit;
+import org.eclipse.jdt.core.dom.ITypeBinding;
+import org.eclipse.jdt.core.dom.ImplicitTypeDeclaration;
+import org.eclipse.jdt.core.dom.Modifier;
+
+public class ASTConverter_24Test extends ConverterTestSetup {
+	ICompilationUnit workingCopy;
+
+	public void setUpSuite() throws Exception {
+		super.setUpSuite();
+		this.ast = AST.newAST(getAST24(), false);
+		this.currentProject = getJavaProject("Converter_24");
+		this.currentProject.setOption(JavaCore.COMPILER_COMPLIANCE, JavaCore.VERSION_24);
+		this.currentProject.setOption(JavaCore.COMPILER_SOURCE, JavaCore.VERSION_24);
+		this.currentProject.setOption(JavaCore.COMPILER_CODEGEN_TARGET_PLATFORM, JavaCore.VERSION_24);
+		this.currentProject.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, JavaCore.ENABLED);
+		this.currentProject.setOption(JavaCore.COMPILER_PB_REPORT_PREVIEW_FEATURES, JavaCore.IGNORE);
+	}
+
+	public ASTConverter_24Test(String name) {
+		super(name);
+	}
+
+	public static Test suite() {
+		return buildModelTestSuite(ASTConverter_24Test.class);
+	}
+
+	static int getAST24() {
+		return AST.JLS24;
+	}
+	protected void tearDown() throws Exception {
+		super.tearDown();
+		if (this.workingCopy != null) {
+			this.workingCopy.discardWorkingCopy();
+			this.workingCopy = null;
+		}
+	}
+	public void test001() throws CoreException {
+		ASTParser astParser = ASTParser.newParser(getAST24());
+	    Map<String, String> options = new HashMap<>();
+	    options.put(JavaCore.COMPILER_COMPLIANCE, "24");
+	    options.put(JavaCore.COMPILER_SOURCE, "24");
+	    options.put(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, JavaCore.ENABLED);
+
+	    astParser.setCompilerOptions(options);
+	    astParser.setEnvironment(new String[] {}, new String[] {}, new String[] {}, true);
+	    astParser.setUnitName("Example.java");
+	    astParser.setResolveBindings(true);
+	    astParser.setBindingsRecovery(true);
+
+	    String source ="""
+		    		String greeting() {
+						return "Hello, World!";
+					}
+					void main() {
+					    System.out.println(greeting());
+					}
+	    		""";
+
+	    astParser.setSource(source.toCharArray());
+
+	    CompilationUnit compilationUnit = (CompilationUnit) astParser.createAST(null);
+	    ImplicitTypeDeclaration a = (ImplicitTypeDeclaration) compilationUnit.types().get(0);
+	    assertTrue(Modifier.isFinal(a.getModifiers()));
+
+	    ITypeBinding aBinding = a.resolveBinding();
+	    assertTrue(Modifier.isFinal(aBinding.getModifiers()));
+	}
+}

org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/RunConverterTests.java

@@ -67,6 +67,7 @@ public static Class[] getAllTestClasses() {
 		ASTConverterSuperAfterStatements.class,
 		ASTConverterEitherOrMultiPatternTest.class,
 		CompilationUnitResolverDiscoveryTest.class,
+		ASTConverter_24Test.class,
 		//ASTConverterMarkdownTest.class
 	};
 }

org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/BodyDeclaration.java

@@ -200,6 +200,8 @@ public int getModifiers() {
 		if (this.modifiers == null) {
 			// JLS2 behavior - bona fide property
 			return this.modifierFlags;
+		} else if (getNodeType() == ASTNode.UNNAMED_CLASS && this.ast.apiLevel >= AST.JLS24) {
+			return Modifier.FINAL;
 		} else {
 			// JLS3 behavior - convenience method
 			// performance could be improved by caching computed flags