Fix to Issue #33 - Can Subclass checking...for inner class constructs...

src/main/java/org/mutabilitydetector/checkers/AccessModifierQuery.java

@@ -22,6 +22,7 @@
 import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
 import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
 import static org.objectweb.asm.Opcodes.ACC_STATIC;
+import static org.objectweb.asm.Opcodes.ACC_SYNTHETIC;
 
 /**
  * Used to check for the existence of an access flag used in ASM visitors.
@@ -77,6 +78,15 @@ public boolean isFinal() {
     public boolean isNotFinal() {
         return !is(ACC_FINAL);
     }
+
+    public boolean isSynthetic() {
+        return !is(ACC_SYNTHETIC);
+    }
+
+    public boolean isNotSynthetic() {
+        return !is(ACC_SYNTHETIC);
+    }
+
 
     public boolean isAbstract() {
         return is(ACC_ABSTRACT);

src/main/java/org/mutabilitydetector/checkers/CanSubclassChecker.java

@@ -39,7 +39,7 @@ public void visit(int version, int access, String name, String signature, String
 
     @Override
     public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
-        if (MethodIs.aConstructor(name) && method(access).isNotPrivate()) {
+        if (MethodIs.aConstructor(name) && (method(access).isNotPrivate()) && method(access).isNotSynthetic()) {
             hasOnlyPrivateConstructors = false;
         }
         return super.visitMethod(access, name, desc, signature, exceptions);

src/test/benchmarks/org/mutabilitydetector/benchmarks/ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern.java

@@ -0,0 +1,5 @@
+package org.mutabilitydetector.benchmarks;
+
+public class ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern {
+
+}

src/test/java/org/mutabilitydetector/benchmarks/CanSubclassCheckerTest.java

@@ -42,6 +42,7 @@
 import org.mutabilitydetector.benchmarks.types.EnumType;
 import org.mutabilitydetector.checkers.CanSubclassChecker;
 import org.mutabilitydetector.locations.ClassLocation;
+import org.mutabilitydetector.unittesting.MutabilityAssert;
 
 @RunWith(Theories.class)
 public class CanSubclassCheckerTest {
@@ -59,6 +60,7 @@ public void createChecker() {
         AnalysisResultTheory.of(HasFinalFieldsAndADefaultConstructor.class, NOT_IMMUTABLE),
         AnalysisResultTheory.of(IsFinalAndHasOnlyPrivateConstructors.class, IMMUTABLE),
         AnalysisResultTheory.of(ImmutableByHavingOnlyPrivateConstructors.class, IMMUTABLE),
+        AnalysisResultTheory.of(ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern.class, IMMUTABLE),
     };
 
     @Theory
@@ -90,4 +92,8 @@ public void hasCodeLocationWithCorrectTypeName() throws Exception {
         assertThat(location.typeName(), is(MutableByNotBeingFinalClass.class.getName()));
     }
 
+    @Test
+    public void privateConstructorsUsingBuilderPatternAreImmutable() throws Exception {
+    	MutabilityAssert.assertImmutable(ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern.class);
+    }
 }