Enhance ExplicitInitialization to handle anonymous classes (#522)

* test: Add test for removing explicit initialization in anonymous subclasses

* refactor: Enhance type checks for class declarations and new classes in ExplicitInitializationVisitor

* test: Add test to ignore explicit initialization in anonymous subclasses

Author: Jammy-Louie

src/main/java/org/openrewrite/staticanalysis/ExplicitInitializationVisitor.java

@@ -48,11 +48,18 @@ public J.VariableDeclarations.NamedVariable visitVariable(J.VariableDeclarations
             return v;
         } else {
             J maybeClassDecl = maybeBlockOrGType
-                    .getParentTreeCursor() // maybe J.ClassDecl
+                    .getParentTreeCursor() // maybe J.ClassDecl or J.NewClass
                     .getValue();
-            if (!(maybeClassDecl instanceof J.ClassDeclaration) ||
-                J.ClassDeclaration.Kind.Type.Class != ((J.ClassDeclaration) maybeClassDecl).getKind() ||
-                !(variableDeclsCursor.getValue() instanceof J.VariableDeclarations)) {
+            if (!(maybeClassDecl instanceof J.ClassDeclaration || maybeClassDecl instanceof J.NewClass)) {
+                return v;
+            }
+
+            if (!(maybeClassDecl instanceof J.NewClass) &&
+                    J.ClassDeclaration.Kind.Type.Class != ((J.ClassDeclaration) maybeClassDecl).getKind()) {
+                return v;
+            }
+
+            if (!(variableDeclsCursor.getValue() instanceof J.VariableDeclarations)) {
                 return v;
             }
         }

src/test/java/org/openrewrite/staticanalysis/ExplicitInitializationTest.java

@@ -195,4 +195,83 @@ class Test {
           )
         );
     }
+
+    @Issue("https://github.com/openrewrite/rewrite-static-analysis/issues/109")
+    @Test
+    void removeExplicitInitializationInAnonymousSubClasses() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class Test {
+                  Object o = new Object() {
+                      private int a = 0;
+                      private long b = 0L;
+                      private short c = 0;
+                      private int d = 1;
+                      private long e = 2L;
+                      private int f;
+                      private char g = '\\0';
+
+                      private boolean h = false;
+                      private boolean i = true;
+
+                      private Object j = new Object();
+                      private Object k = null;
+
+                      int[] l = null;
+                      int[] m = new int[0];
+
+                      private final Long n = null;
+                  };
+              }
+              """,
+            """
+              class Test {
+                  Object o = new Object() {
+                      private int a;
+                      private long b;
+                      private short c;
+                      private int d = 1;
+                      private long e = 2L;
+                      private int f;
+                      private char g;
+
+                      private boolean h;
+                      private boolean i = true;
+
+                      private Object j = new Object();
+                      private Object k;
+
+                      int[] l;
+                      int[] m = new int[0];
+
+                      private final Long n = null;
+                  };
+              }
+              """
+          )
+        );
+    }
+
+    @Issue("https://github.com/openrewrite/rewrite-static-analysis/issues/109")
+    @Test
+    void ignoreInAnonymousSubClasses() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class Test {
+                  Object o = new Object() {
+                      private final boolean b = false;
+
+                      private void method() {
+                          int i = 0;
+                      }
+                  };
+              }
+              """
+          )
+        );
+    }
 }