Adding test cases for folding

org.eclipse.jdt.text.tests/src/org/eclipse/jdt/text/tests/JdtTextTestSuite.java

@@ -20,6 +20,7 @@
 import org.eclipse.jdt.text.tests.codemining.CodeMiningTriggerTest;
 import org.eclipse.jdt.text.tests.codemining.ParameterNamesCodeMiningTest;
 import org.eclipse.jdt.text.tests.contentassist.ContentAssistTestSuite;
+import org.eclipse.jdt.text.tests.folding.FoldingTest;
 import org.eclipse.jdt.text.tests.semantictokens.SemanticTokensProviderTest;
 import org.eclipse.jdt.text.tests.spelling.SpellCheckEngineTestCase;
 import org.eclipse.jdt.text.tests.templates.TemplatesTestSuite;
@@ -70,6 +71,7 @@
 	JavaElementPrefixPatternMatcherTest.class,
 	CodeMiningTriggerTest.class,
 	ParameterNamesCodeMiningTest.class,
+	FoldingTest.class,
 })
 public class JdtTextTestSuite {
 }

org.eclipse.jdt.text.tests/src/org/eclipse/jdt/text/tests/folding/FoldingTest.java

@@ -0,0 +1,220 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Vector Informatik GmbH 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:
+ *     Vector Informatik GmbH - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.text.tests.folding;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.eclipse.jdt.testplugin.JavaProjectHelper;
+
+import org.eclipse.core.runtime.CoreException;
+
+import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.IPackageFragment;
+import org.eclipse.jdt.core.IPackageFragmentRoot;
+
+import org.eclipse.jdt.ui.tests.core.rules.ProjectTestSetup;
+
+public class FoldingTest {
+	@Rule
+	public ProjectTestSetup projectSetup= new ProjectTestSetup();
+
+	private IJavaProject jProject;
+
+	private IPackageFragmentRoot sourceFolder;
+
+	private IPackageFragment packageFragment;
+
+	@Before
+	public void setUp() throws CoreException {
+		jProject= projectSetup.getProject();
+		sourceFolder= jProject.findPackageFragmentRoot(jProject.getResource().getFullPath().append("src"));
+		if (sourceFolder == null) {
+			sourceFolder= JavaProjectHelper.addSourceContainer(jProject, "src");
+		}
+		packageFragment= sourceFolder.createPackageFragment("org.example.test", false, null);
+	}
+
+	@After
+	public void tearDown() throws CoreException {
+		JavaProjectHelper.delete(jProject);
+	}
+
+	@Test
+	public void testCompilationUnitFolding() throws Exception {
+		String str= """
+				package org.example.test;
+				public class A {		//here should not be an annotation
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 0);
+	}
+
+	@Test
+	public void testClassWithJavadocAsHeaderComment() throws Exception {
+		String str= """
+				package org.example.test;
+				/**									//here should not be an annotation
+				 * Javadoc
+				 */
+				public class HeaderCommentTest {
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 1);
+	}
+
+	@Test
+	public void testImportsFolding() throws Exception {
+		String str= """
+				package org.example.test;
+
+				import java.util.List;				//here should not be an annotation
+				import java.util.ArrayList;
+
+				public class ImportsTest {
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 1);
+	}
+
+	@Test
+	public void testSingleMethodWithJavadoc() throws Exception {
+		String str= """
+				package org.example.test;
+				public class SingleMethodTest {
+				    /**									//here should not be an annotation
+				     * Javadoc
+				     */
+				    public void foo() {					//here should not be an annotation
+				        System.out.println("Hello");
+				    }
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 2);
+	}
+
+	@Test
+	public void testMultipleMethodsWithoutComments() throws Exception {
+		String str= """
+				package org.example.test;
+				public class MultipleMethodTest {
+				    public void foo() {					//here should not be an annotation
+
+				    }
+				    public void bar() {					//here should not be an annotation
+
+				    }
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 2);
+	}
+
+	@Test
+	public void testInnerClassFolding() throws Exception {
+		String str= """
+				package org.example.test;
+				public class OuterClass {
+				    class InnerClass {				//here should not be an annotation
+				        void bar() {				//here should not be an annotation
+
+				        }
+				    }
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 2);
+	}
+
+	@Test
+	public void testInnerClassWithJavadoc() throws Exception {
+		String str= """
+				package org.example.test;
+				public class OuterWithDocs {
+				    /**										//here should not be an annotation
+				     * Javadoc
+				     */
+				    class InnerWithDocs {					//here should not be an annotation
+				        /**									//here should not be an annotation
+				         * Javadoc
+				         */
+				        void bar() {						//here should not be an annotation
+
+				        }
+				    }
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 4);
+	}
+
+	@Test
+	public void testJavadocs() throws Exception {
+		String str= """
+				package org.example.test;
+				   /**										//here should be an annotation
+				    * Javadoc
+				    */
+				    /**										//here should be an annotation
+				    * Another Javadoc
+				    */
+				    /**										//here should be an annotation
+				    * Yet another Javadoc
+				    */
+				    public class Example {}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 3);
+	}
+
+	@Test
+	public void testCommentBlocks() throws Exception {
+		String str= """
+				package org.example.test;
+				   /* 						//here should be an annotation
+				 *
+				 */
+				/* 							//here should be an annotation
+				 *
+				 */
+				/* 							//here should be an annotation
+				 *
+				 */
+				class h {
+
+					/* 						//here should be an annotation
+					 *
+					 */
+					void b() { 				//here should be an annotation
+						/* 					//here should NOT be an annotation
+						 *
+						 */
+						int a;
+					}
+				}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 5);
+	}
+
+	@Test
+	public void testCopyrightHeader() throws Exception {
+		String str= """
+				/**							//here should be an annotation
+				* This is some copyright header
+				*/
+				package org.example.test;
+
+				class SomeClass {}
+				""";
+		FoldingTestUtils.assertCodeHasRegions(packageFragment, "TestFolding.java", str, 1);
+	}
+}

org.eclipse.jdt.text.tests/src/org/eclipse/jdt/text/tests/folding/FoldingTestUtils.java

@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Vector Informatik GmbH 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:
+ *     Vector Informatik GmbH - initial API and implementation
+ *     Daniel Schmid - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.text.tests.folding;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.Position;
+import org.eclipse.jface.text.Region;
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.projection.ProjectionAnnotation;
+import org.eclipse.jface.text.source.projection.ProjectionAnnotationModel;
+
+import org.eclipse.jdt.core.ICompilationUnit;
+import org.eclipse.jdt.core.IPackageFragment;
+
+import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
+import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;
+
+public final class FoldingTestUtils {
+
+	private FoldingTestUtils() {
+	}
+
+	public static List<IRegion> getProjectionRangesOfFile(IPackageFragment packageFragment, String fileName, String code) throws Exception {
+		ICompilationUnit cu= packageFragment.createCompilationUnit(fileName, code, true, null);
+		JavaEditor editor= (JavaEditor) EditorUtility.openInEditor(cu);
+		ProjectionAnnotationModel model= editor.getAdapter(ProjectionAnnotationModel.class);
+
+		List<IRegion> regions= new ArrayList<>();
+		Iterator<Annotation> it= model.getAnnotationIterator();
+		while (it.hasNext()) {
+			Annotation a= it.next();
+			if (a instanceof ProjectionAnnotation) {
+				Position p= model.getPosition(a);
+				regions.add(new Region(p.getOffset(), p.getLength()));
+			}
+		}
+		return regions;
+	}
+
+	public static void assertCodeHasRegions(IPackageFragment packageFragment, String fileName, String code, int regionsCount) throws Exception {
+		List<IRegion> regions= FoldingTestUtils.getProjectionRangesOfFile(packageFragment, fileName, code);
+		assertEquals(regionsCount, regions.size(), String.format("Expected %d regions but saw %d.", regionsCount, regions.size()));
+	}
+}