Fix 4457

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/OverrideBothEqualsAndHashcodeRule.java

@@ -5,6 +5,7 @@
 package net.sourceforge.pmd.lang.java.rule.errorprone;
 
 import net.sourceforge.pmd.lang.ast.Node;
+import net.sourceforge.pmd.lang.java.ast.ASTAnonymousClassDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTFormalParameter;
 import net.sourceforge.pmd.lang.java.ast.ASTImplementsList;
@@ -42,6 +43,25 @@ public class OverrideBothEqualsAndHashcodeRule extends AbstractJavaRule {
         return data;
     }
 
+    @Override
+    public Object visit(ASTAnonymousClassDeclaration node, Object data) {
+        if (node.isInterface()) {
+            return data;
+        }
+        super.visit(node, data);
+        if (!implementsComparable && containsEquals ^ containsHashCode) {
+            if (nodeFound == null) {
+                nodeFound = node;
+            }
+            addViolation(data, nodeFound);
+        }
+        implementsComparable = false;
+        containsEquals = false;
+        containsHashCode = false;
+        nodeFound = null;
+        return data;
+    }
+
     @Override
     public Object visit(ASTImplementsList node, Object data) {
         implementsComparable = node.children().filter(child -> TypeTestUtil.isA(Comparable.class, (TypeNode) child)).nonEmpty();

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/OverrideBothEqualsAndHashcode.xml

@@ -177,6 +177,25 @@ public class Foo implements C {
 public class Foo implements Runnable {
     public boolean equals(Object other) { return false; }
     public int compareTo(Object other) { return 42; }
+}
+        ]]></code>
+    </test-code>
+
+    <test-code>
+        <description> [java]A false negative about OverrideBothEqualsAndHashcode #4457 </description>
+        <expected-problems>2</expected-problems>
+        <code><![CDATA[
+public class Foo {
+  public class B {
+      Object o = new Object() {
+          public boolean equals(Object other) {   // report no warning
+              return false;
+          }
+      };
+      public int hashCode() {
+          return 1;
+      }
+  }
 }
         ]]></code>
     </test-code>