Indicate in code which methods are not covered by Jacoco instead of being forced to drop the coverage ratio

org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/ManuallyIgnoredFilterTest.java

@@ -0,0 +1,86 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2024 Mountainminds GmbH & Co. KG and Contributors
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Orestis Gkorgkas - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.internal.analysis.filter;
+
+import org.jacoco.core.internal.instr.InstrSupport;
+import org.junit.Test;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.MethodNode;
+
+/**
+ * Unit tests for {@link ManuallyIgnoredFilter}.
+ */
+public class ManuallyIgnoredFilterTest extends FilterTestBase {
+
+	public static final String SOME_METHOD_NAME = "someMethodName";
+	private static final String ANNOTATION_VALUE = "L"
+			+ ManuallyIgnoredFilter.ANNOTATION_VALUE + ";";
+	private final IFilter filter = new ManuallyIgnoredFilter();
+
+	@Test
+	public void should_filter_methods_annotated_with_runtime_invisible_annotation_JacocoIgnored() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				SOME_METHOD_NAME, "()I", null, null);
+		m.visitAnnotation(ANNOTATION_VALUE, true);
+
+		m.visitInsn(Opcodes.ICONST_0);
+		m.visitInsn(Opcodes.IRETURN);
+
+		filter.filter(m, context, output);
+
+		assertMethodIgnored(m);
+	}
+
+	@Test
+	public void should_filter_classes_annotated_with_runtime_visible_annotation_JacocoIgnored() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				"readExternal", "()V", null, null);
+
+		m.visitInsn(Opcodes.NOP);
+		context.classAnnotations.add(ANNOTATION_VALUE);
+
+		filter.filter(m, context, output);
+
+		assertMethodIgnored(m);
+	}
+
+	@Test
+	public void should_not_filter_when_no_annotations() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				"hashCode", "()I", null, null);
+
+		m.visitInsn(Opcodes.ICONST_0);
+		m.visitInsn(Opcodes.IRETURN);
+
+		filter.filter(m, context, output);
+
+		assertIgnored();
+	}
+
+	@Test
+	public void should_not_filter_when_other_annotations() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				"hashCode", "()I", null, null);
+		m.visitAnnotation("LOtherAnnotation;", true);
+
+		m.visitInsn(Opcodes.ICONST_0);
+		m.visitInsn(Opcodes.IRETURN);
+
+		context.classAnnotations.add("LOtherAnnotation;");
+
+		filter.filter(m, context, output);
+
+		assertIgnored();
+	}
+
+}

org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java

@@ -48,7 +48,8 @@ public static IFilter all() {
 				new KotlinUnsafeCastOperatorFilter(),
 				new KotlinNotNullOperatorFilter(),
 				new KotlinDefaultArgumentsFilter(), new KotlinInlineFilter(),
-				new KotlinCoroutineFilter(), new KotlinDefaultMethodsFilter());
+				new KotlinCoroutineFilter(), new KotlinDefaultMethodsFilter(),
+				new ManuallyIgnoredFilter());
 	}
 
 	private Filters(final IFilter... filters) {

org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/ManuallyIgnoredFilter.java

@@ -0,0 +1,67 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2024 Mountainminds GmbH & Co. KG and Contributors
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Orestis Gkorgkas - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.internal.analysis.filter;
+
+import java.util.List;
+
+import org.objectweb.asm.tree.AnnotationNode;
+import org.objectweb.asm.tree.MethodNode;
+
+/**
+ * Filters out any annotation that is named has the value "JacocoIgnored".
+ * Example: The following method that for some reason is not reachable by tests
+ * will be ignored by Jacoco:
+ *
+ * <pre>{@code @JacocoIgnored
+ * public void foo(Object bar) {
+ * 	// DO SOMETHING HERE
+ * }
+ *
+ * }</pre>
+ */
+public class ManuallyIgnoredFilter implements IFilter {
+
+	public static final String ANNOTATION_VALUE = "JacocoIgnored";
+
+	public void filter(MethodNode methodNode, IFilterContext context,
+			IFilterOutput output) {
+		for (String annotation : context.getClassAnnotations()) {
+			if (matches(annotation)) {
+				output.ignore(methodNode.instructions.getFirst(),
+						methodNode.instructions.getLast());
+				return;
+			}
+		}
+
+		if (presentIn(methodNode.visibleAnnotations)) {
+			output.ignore(methodNode.instructions.getFirst(),
+					methodNode.instructions.getLast());
+		}
+
+	}
+
+	private static boolean matches(final String annotation) {
+		return annotation.contains(ANNOTATION_VALUE);
+	}
+
+	private static boolean presentIn(final List<AnnotationNode> annotations) {
+		if (annotations != null) {
+			for (AnnotationNode annotation : annotations) {
+				if (matches(annotation.desc)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+}