Issue checkstyle#14092: fix UnusedLocalVariableCheck to support local…

… classes

src/main/java/com/puppycrawl/tools/checkstyle/checks/coding/UnusedLocalVariableCheck.java

@@ -421,7 +421,8 @@ private static void addLocalVariables(DetailAST varDefAst, Deque<VariableDesc> v
         final DetailAST parentAst = varDefAst.getParent();
         final DetailAST grandParent = parentAst.getParent();
         final boolean isInstanceVarInAnonymousInnerClass =
-                grandParent.getType() == TokenTypes.LITERAL_NEW;
+                grandParent.getType() == TokenTypes.LITERAL_NEW
+                || grandParent.getType() == TokenTypes.CLASS_DEF;
         if (isInstanceVarInAnonymousInnerClass
                 || parentAst.getType() != TokenTypes.OBJBLOCK) {
             final DetailAST ident = varDefAst.findFirstToken(TokenTypes.IDENT);

src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/UnusedLocalVariableCheckTest.java

@@ -241,6 +241,47 @@ public void testUnusedLocalVarNestedClasses3() throws Exception {
                 expected);
     }
 
+    @Test
+    public void testUnusedLocalVarNestedClasses4() throws Exception {
+        final String[] expected = {
+            "18:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "a"),
+            "19:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "ab"),
+        };
+
+        verifyWithInlineConfigParser(
+                getPath("InputUnusedLocalVariableNestedClasses4.java"),
+                expected);
+    }
+
+    @Test
+    public void testUnusedLocalVarNestedClasses5() throws Exception {
+        final String[] expected = {
+            "18:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "a"),
+            "19:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "ab"),
+            "25:11: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "abc"),
+        };
+
+        verifyWithInlineConfigParser(
+                getPath("InputUnusedLocalVariableNestedClasses5.java"),
+                expected);
+    }
+
+    @Test
+    public void testUnusedLocalVarNestedClasses6() throws Exception {
+        final String[] expected = {
+            "16:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "a"),
+            "17:5: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "ab"),
+            "22:9: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "ab"),
+            "29:9: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "a"),
+            "30:9: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "ab"),
+            "34:13: " + getCheckMessage(MSG_UNUSED_LOCAL_VARIABLE, "a"),
+        };
+
+        verifyWithInlineConfigParser(
+                getPath("InputUnusedLocalVariableNestedClasses6.java"),
+                expected);
+    }
+
     @Test
     public void testUnusedLocalVarTestWarningSeverity() throws Exception {
         final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;

src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/unusedlocalvariable/InputUnusedLocalVariableNestedClasses4.java

@@ -0,0 +1,29 @@
+/*xml
+<module name="Checker">
+    <property name="charset" value="UTF-8" />
+    <property name="severity" value="warning" />
+    <property name="haltOnException" value="false" />
+    <module name="TreeWalker">
+        <module name="UnusedLocalVariable">
+        </module>
+    </module>
+</module>
+*/
+package com.puppycrawl.tools.checkstyle.checks.coding.unusedlocalvariable;
+
+public class InputUnusedLocalVariableNestedClasses4 {
+  int a = 12;
+
+  void foo() {
+    int a = 12; // violation, unused variable 'a'
+    int ab = 12; // violation, unused variable 'ab'
+
+    class asd {
+      Test a = new Test() {
+        void asd() {
+          System.out.println(a);
+        }
+      };
+    }
+  }
+}

src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/unusedlocalvariable/InputUnusedLocalVariableNestedClasses5.java

@@ -0,0 +1,38 @@
+/*xml
+<module name="Checker">
+    <property name="charset" value="UTF-8" />
+    <property name="severity" value="warning" />
+    <property name="haltOnException" value="false" />
+    <module name="TreeWalker">
+        <module name="UnusedLocalVariable">
+        </module>
+    </module>
+</module>
+*/
+package com.puppycrawl.tools.checkstyle.checks.coding.unusedlocalvariable;
+
+public class InputUnusedLocalVariableNestedClasses5 {
+  int a = 12;
+
+  void foo() {
+    int a = 12; // violation, unused variable 'a'
+    int ab = 12; // violation, unused variable 'ab'
+
+    class abc {
+      Test a = new Test() {
+        void abc() {
+          System.out.println(a);
+          int abc = 10; // violation, unused variable 'abc'
+
+          class def {
+            Test abc = new Test() {
+              void def() {
+                System.out.println(abc);
+              }
+            };
+          }
+        }
+      };
+    }
+  }
+}

src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/unusedlocalvariable/InputUnusedLocalVariableNestedClasses6.java

@@ -0,0 +1,42 @@
+/*xml
+<module name="Checker">
+    <property name="charset" value="UTF-8" />
+    <property name="severity" value="warning" />
+    <property name="haltOnException" value="false" />
+    <module name="TreeWalker">
+        <module name="UnusedLocalVariable">
+        </module>
+    </module>
+</module>
+*/
+package com.puppycrawl.tools.checkstyle.checks.coding.unusedlocalvariable;
+
+public class InputUnusedLocalVariableNestedClasses6 {
+  void foo() {
+    int a = 12; // violation, unused variable 'a'
+    int ab = 12; // violation, unused variable 'ab'
+
+    class Ghi {
+      void foo() {
+        int a = 12;
+        int ab = 12; // violation, unused variable 'ab'
+        System.out.println(a);
+      }
+    }
+
+    class Def {
+      void foo() {
+        int a = 12; // violation, unused variable 'a'
+        int ab = 12; // violation, unused variable 'ab'
+
+        class InnerDef {
+          void foo() {
+            int a = 12; // violation, unused variable 'a'
+            int ab = 12;
+            System.out.println(ab);
+          }
+        }
+      }
+    }
+  }
+}