Avoid instrumenting synthetic methods

README.md

@@ -8,7 +8,11 @@ Read all about it at http://pitest.org
 
 ## Releases
 
-## 1.11.0 (unreleased)
+## 1.11.1
+
+* #1156 Prevent synthetic lines being counted in coverage
+
+## 1.11.0
 
 * #1138 Do not mutate redundant fall through to default switch cases
 * #1150 New extension points

pitest/src/main/java/org/pitest/classinfo/SyntheticMethodFilter.java

@@ -0,0 +1,30 @@
+package org.pitest.classinfo;
+
+import org.objectweb.asm.Opcodes;
+import org.pitest.functional.F5;
+
+/**
+ * Filters out synthetic and bridge methods, but allows synthetic
+ * lambdas. This logic is duplicated in org.pitest.bytecode.analysis.MethodTree
+ * when identifying code lines.
+ */
+public enum SyntheticMethodFilter implements
+        F5<Integer, String, String, String, String[], Boolean> {
+
+    INSTANCE;
+
+    @Override
+    public Boolean apply(final Integer access, final String name,
+                         final String desc, final String signature, final String[] exceptions) {
+        return (!isSynthetic(access, name) && !isBridge(access));
+    }
+
+    private static boolean isSynthetic(final int access, String name) {
+        return (access & Opcodes.ACC_SYNTHETIC) != 0 && !name.startsWith("lambda$");
+    }
+
+    private static boolean isBridge(final Integer access) {
+        return (access & Opcodes.ACC_BRIDGE) != 0;
+    }
+
+}

pitest/src/main/java/org/pitest/coverage/CoverageClassVisitor.java

@@ -21,8 +21,8 @@
 import org.objectweb.asm.FieldVisitor;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
-import org.pitest.classinfo.BridgeMethodFilter;
 import org.pitest.classinfo.MethodFilteringAdapter;
+import org.pitest.classinfo.SyntheticMethodFilter;
 import org.pitest.coverage.analysis.CoverageAnalyser;
 import sun.pitest.CodeCoverageStore;
 
@@ -43,7 +43,7 @@ public class CoverageClassVisitor extends MethodFilteringAdapter {
   private boolean   isInterface;
 
   public CoverageClassVisitor(final int classId, final ClassWriter writer) {
-    super(writer, BridgeMethodFilter.INSTANCE);
+    super(writer, SyntheticMethodFilter.INSTANCE);
     this.classId = classId;
   }
 

pitest/src/test/java/org/pitest/coverage/CoverageTransformerTest.java

@@ -55,16 +55,14 @@ public void tearDown() {
   }
 
   @Test
-  public void shouldNotTransformClassesNotMatchingPredicate()
-      throws IllegalClassFormatException {
+  public void shouldNotTransformClassesNotMatchingPredicate() {
     final CoverageTransformer testee = new CoverageTransformer(
         False.<String> instance());
     assertNull(testee.transform(null, "anything", null, null, null));
   }
 
   @Test
-  public void shouldTransformClasseMatchingPredicate()
-      throws IllegalClassFormatException {
+  public void shouldTransformClasseMatchingPredicate() {
     final CoverageTransformer testee = new CoverageTransformer(
         s -> true);
     final byte[] bs = this.bytes.getBytes(String.class.getName()).get();
@@ -83,8 +81,7 @@ public void shouldGenerateValidClasses() throws IllegalClassFormatException {
     assertValidClass(Math.class);
   }
 
-  private void assertValidClass(final Class<?> clazz)
-      throws IllegalClassFormatException {
+  private void assertValidClass(final Class<?> clazz) {
     final byte[] bs = transform(clazz);
     // printClass(bs);
     final StringWriter sw = new StringWriter();
@@ -105,8 +102,7 @@ protected void printClass(final byte[] bs) {
         System.out)), ClassReader.EXPAND_FRAMES);
   }
 
-  private byte[] transform(final Class<?> clazz)
-      throws IllegalClassFormatException {
+  private byte[] transform(final Class<?> clazz) {
     final CoverageTransformer testee = new CoverageTransformer(
         s -> true);
     return testee.transform(this.loader, clazz.getName(), null,