Introduce scoped variable trait

rewrite-java/src/main/java/org/openrewrite/java/ChangeFieldName.java

@@ -18,27 +18,43 @@
 import lombok.EqualsAndHashCode;
 import lombok.Value;
 import org.jspecify.annotations.Nullable;
+import org.openrewrite.java.trait.ScopedVariable;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JLeftPadded;
 import org.openrewrite.java.tree.JavaType;
 import org.openrewrite.java.tree.TypeUtils;
 
+import java.util.HashMap;
+import java.util.Map;
+
 @Value
 @EqualsAndHashCode(callSuper = false)
 public class ChangeFieldName<P> extends JavaIsoVisitor<P> {
     String classType;
     String hasName;
     String toName;
 
+    Map<J.Identifier, ScopedVariable> scopedVariableMap = new HashMap<>();
+
+
+    @Override
+    public J.CompilationUnit visitCompilationUnit(J.CompilationUnit cu, P p) {
+        new ScopedVariable.Matcher().asVisitor(var -> {
+            scopedVariableMap.put(var.getIdentifier(), var);
+            return var.getTree();
+        }).visit(cu, p);
+        return super.visitCompilationUnit(cu, p);
+    }
+
     @Override
     public J.VariableDeclarations.NamedVariable visitVariable(J.VariableDeclarations.NamedVariable variable, P p) {
         J.VariableDeclarations.NamedVariable v = super.visitVariable(variable, p);
         J.ClassDeclaration enclosingClass = getCursor().firstEnclosing(J.ClassDeclaration.class);
         if (enclosingClass == null) {
             return v;
         }
-        if (variable.isField(getCursor()) && matchesClass(enclosingClass.getType()) &&
-                variable.getSimpleName().equals(hasName)) {
+        if (scopedVariableMap.get(variable.getName()).isField(getCursor()) && matchesClass(enclosingClass.getType()) &&
+            variable.getSimpleName().equals(hasName)) {
             if (v.getVariableType() != null) {
                 v = v.withVariableType(v.getVariableType().withName(toName));
             }
@@ -54,7 +70,7 @@ public J.VariableDeclarations.NamedVariable visitVariable(J.VariableDeclarations
     public J.FieldAccess visitFieldAccess(J.FieldAccess fieldAccess, P p) {
         J.FieldAccess f = super.visitFieldAccess(fieldAccess, p);
         if (matchesClass(fieldAccess.getTarget().getType()) &&
-                fieldAccess.getSimpleName().equals(hasName)) {
+            fieldAccess.getSimpleName().equals(hasName)) {
             f = f.getPadding().withName(f.getPadding().getName().withElement(f.getPadding().getName().getElement().withSimpleName(toName)));
         }
         return f;

rewrite-java/src/main/java/org/openrewrite/java/GenerateGetterAndSetterVisitor.java

@@ -18,11 +18,15 @@
 import org.openrewrite.Cursor;
 import org.openrewrite.internal.ListUtils;
 import org.openrewrite.internal.StringUtils;
+import org.openrewrite.java.trait.ScopedVariable;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;
 import org.openrewrite.java.tree.Statement;
 import org.openrewrite.java.tree.TypeUtils;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import static java.util.Collections.emptyList;
 
 public class GenerateGetterAndSetterVisitor<P> extends JavaIsoVisitor<P> {
@@ -38,9 +42,20 @@ public GenerateGetterAndSetterVisitor(String fieldName) {
         this.capitalizedFieldName = StringUtils.capitalize(fieldName);
     }
 
+    private Map<J.Identifier, ScopedVariable> scopedVariableMap = new HashMap<>();
+
+    @Override
+    public J.CompilationUnit visitCompilationUnit(J.CompilationUnit cu, P p) {
+        new ScopedVariable.Matcher().asVisitor(var -> {
+            scopedVariableMap.put(var.getIdentifier(), var);
+            return var.getTree();
+        }).visit(cu, p);
+        return super.visitCompilationUnit(cu, p);
+    }
+
     @Override
     public J.VariableDeclarations.NamedVariable visitVariable(J.VariableDeclarations.NamedVariable variable, P p) {
-        if (variable.isField(getCursor()) && variable.getSimpleName().equals(fieldName)) {
+        if (scopedVariableMap.get(variable.getName()).isField(getCursor()) && variable.getSimpleName().equals(fieldName)) {
             getCursor().putMessageOnFirstEnclosing(J.ClassDeclaration.class, "varCursor", getCursor());
         }
         return super.visitVariable(variable, p);

rewrite-java/src/main/java/org/openrewrite/java/VariableNameUtils.java

@@ -19,6 +19,7 @@
 import org.jspecify.annotations.Nullable;
 import org.openrewrite.Cursor;
 import org.openrewrite.Incubating;
+import org.openrewrite.java.trait.ScopedVariable;
 import org.openrewrite.java.tree.*;
 
 import java.text.Normalizer;

rewrite-java/src/main/java/org/openrewrite/java/trait/ScopedVariable.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.java.trait;
+
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+import org.jspecify.annotations.Nullable;
+import org.openrewrite.Cursor;
+import org.openrewrite.java.tree.J;
+import org.openrewrite.trait.SimpleTraitMatcher;
+import org.openrewrite.trait.Trait;
+
+@Value
+public class ScopedVariable implements Trait<J.VariableDeclarations.NamedVariable> {
+    Cursor cursor;
+    Cursor scope;
+    J.Identifier identifier;
+
+    public boolean isField(Cursor cursor) {
+        return scope.getValue() instanceof J.Block &&
+               scope.getParentTreeCursor().getValue() instanceof J.ClassDeclaration;
+    }
+
+    @RequiredArgsConstructor
+    public static class Matcher extends SimpleTraitMatcher<ScopedVariable> {
+
+        @Override
+        protected @Nullable ScopedVariable test(Cursor cursor) {
+            if (cursor.getValue() instanceof J.VariableDeclarations.NamedVariable) {
+                J.VariableDeclarations.NamedVariable variable = cursor.getValue();
+                return new ScopedVariable(cursor, this.getDeclaringScope(cursor), variable.getName());
+            }
+            return null;
+        }
+
+        private Cursor getDeclaringScope(Cursor cursor) {
+            return cursor.dropParentUntil(it ->
+                    it instanceof J.Block ||
+                    it instanceof J.Lambda ||
+                    it instanceof J.MethodDeclaration ||
+                    it == Cursor.ROOT_VALUE);
+        }
+    }
+}

rewrite-java/src/test/java/org/openrewrite/java/trait/ScopedVariableTest.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.java.trait;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.InMemoryExecutionContext;
+import org.openrewrite.Recipe;
+import org.openrewrite.java.tree.J;
+import org.openrewrite.marker.SearchResult;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.openrewrite.java.Assertions.java;
+
+class ScopedVariableTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(RewriteTest.toRecipe(() ->
+          new ScopedVariable.Matcher().asVisitor(a -> SearchResult.found(a.getTree(),
+              String.format("Identified variable %s within scope %s", a.getIdentifier(), a.getScope().getValue().getClass().getSimpleName())
+            )
+          )
+        ));
+    }
+
+    @Test
+    @DocumentExample
+    void markAllFieldsInClass() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class Test {
+                  private String field;
+
+                  void doSome() {
+                      String anotherField;
+                  }
+              }
+              """,
+            """
+              class Test {
+                  private String /*~~(Identified variable field within scope Block)~~>*/field;
+
+                  void doSome() {
+                      String /*~~(Identified variable anotherField within scope Block)~~>*/anotherField;
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void markAllFieldsInMethod() {
+        rewriteRun(
+          spec -> spec.recipe(Recipe.noop()),
+          //language=java
+          java(
+            """
+              class Test {
+                  private String field;
+
+                  void doSome() {
+                      String anotherField;
+                  }
+              }
+              """,
+            spec -> spec.beforeRecipe((source) -> {
+                J.MethodDeclaration md = (J.MethodDeclaration) source.getClasses().get(0).getBody().getStatements().get(1);
+                new ScopedVariable.Matcher().asVisitor(var -> {
+                    assertThat(((J.Block) var.getScope().getValue())).isEqualTo(md.getBody());
+                    return var.getTree();
+                }).visit(md, new InMemoryExecutionContext());
+            })
+          )
+        );
+    }
+
+}