code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  // Copyright (C) 2001-2023 the original author or authors.
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.modifier;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.checks.modifier.RedundantModifierCheck.MSG_KEY;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.DetailAstImpl;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  public class RedundantModifierCheckTest
      extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/modifier/redundantmodifier";
      }
  
      @Test
      public void testClassesInsideOfInterfaces() throws Exception {
          final String[] expected = {
              "19:5: " + getCheckMessage(MSG_KEY, "static"),
              "25:5: " + getCheckMessage(MSG_KEY, "public"),
              "28:5: " + getCheckMessage(MSG_KEY, "public"),
              "34:5: " + getCheckMessage(MSG_KEY, "static"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierClassesInsideOfInterfaces.java"),
              expected);
      }
  
      @Test
      public void testIt() throws Exception {
          final String[] expected = {
              "57:12: " + getCheckMessage(MSG_KEY, "static"),
              "60:9: " + getCheckMessage(MSG_KEY, "public"),
              "66:9: " + getCheckMessage(MSG_KEY, "abstract"),
              "69:9: " + getCheckMessage(MSG_KEY, "public"),
              // "72:9: Redundant 'abstract' modifier.",
              "75:9: " + getCheckMessage(MSG_KEY, "final"),
              "82:13: " + getCheckMessage(MSG_KEY, "final"),
              "91:12: " + getCheckMessage(MSG_KEY, "final"),
              "102:1: " + getCheckMessage(MSG_KEY, "abstract"),
              "119:5: " + getCheckMessage(MSG_KEY, "public"),
              "120:5: " + getCheckMessage(MSG_KEY, "final"),
              "121:5: " + getCheckMessage(MSG_KEY, "static"),
              "123:5: " + getCheckMessage(MSG_KEY, "public"),
              "124:5: " + getCheckMessage(MSG_KEY, "abstract"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierIt.java"), expected);
      }
  
      @Test
      public void testStaticMethodInInterface()
              throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierStaticMethodInInterface.java"),
              expected);
      }
  
      @Test
      public void testFinalInInterface()
              throws Exception {
          final String[] expected = {
              "13:9: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInInterface.java"), expected);
      }
  
      @Test
      public void testEnumConstructorIsImplicitlyPrivate() throws Exception {
          final String[] expected = {
              "14:5: " + getCheckMessage(MSG_KEY, "private"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierConstructorModifier.java"), expected);
      }
  
      @Test
      public void testInnerTypeInInterfaceIsImplicitlyStatic() throws Exception {
          final String[] expected = {
              "12:5: " + getCheckMessage(MSG_KEY, "static"),
              "16:5: " + getCheckMessage(MSG_KEY, "static"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierStaticInInnerTypeOfInterface.java"),
              expected);
      }
  
      @Test
      public void testNotPublicClassConstructorHasNotPublicModifier() throws Exception {
  
          final String[] expected = {
              "22:5: " + getCheckMessage(MSG_KEY, "public"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierPublicModifierInNotPublicClass.java"),
              expected);
      }
  
      @Test
      public void testNestedClassConsInPublicInterfaceHasValidPublicModifier() throws Exception {
  
          final String[] expected = {
              "22:17: " + getCheckMessage(MSG_KEY, "public"),
              "24:13: " + getCheckMessage(MSG_KEY, "public"),
              "26:21: " + getCheckMessage(MSG_KEY, "public"),
              "37:12: " + getCheckMessage(MSG_KEY, "public"),
              "45:17: " + getCheckMessage(MSG_KEY, "public"),
          };
  
          verifyWithInlineConfigParser(
              getPath("InputRedundantModifierNestedClassInPublicInterfaceRedundantModifiers.java"),
              expected);
      }
  
      @Test
      public void testGetAcceptableTokens() {
          final RedundantModifierCheck redundantModifierCheckObj = new RedundantModifierCheck();
          final int[] actual = redundantModifierCheckObj.getAcceptableTokens();
          final int[] expected = {
              TokenTypes.METHOD_DEF,
              TokenTypes.VARIABLE_DEF,
              TokenTypes.ANNOTATION_FIELD_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.CTOR_DEF,
              TokenTypes.CLASS_DEF,
              TokenTypes.ENUM_DEF,
              TokenTypes.RESOURCE,
              TokenTypes.ANNOTATION_DEF,
              TokenTypes.RECORD_DEF,
          };
          assertWithMessage("Invalid acceptable tokens")
              .that(actual)
              .isEqualTo(expected);
      }
  
      @Test
      public void testWrongTokenType() {
          final RedundantModifierCheck obj = new RedundantModifierCheck();
          final DetailAstImpl ast = new DetailAstImpl();
          ast.initialize(TokenTypes.LITERAL_NULL, "null");
  
          final IllegalStateException exception = assertThrows(IllegalStateException.class, () -> {
              obj.visitToken(ast);
          }, "IllegalStateException was expected");
  
          assertWithMessage("Expected and actual violation messages do not match")
                  .that(exception.getMessage())
                  .isEqualTo("Unexpected token type: " + ast.getType());
      }
  
      @Test
      public void testGetRequiredTokens() {
          final RedundantModifierCheck redundantModifierCheckObj = new RedundantModifierCheck();
          final int[] actual = redundantModifierCheckObj.getRequiredTokens();
          final int[] expected = CommonUtil.EMPTY_INT_ARRAY;
          assertWithMessage("Invalid required tokens")
              .that(actual)
              .isEqualTo(expected);
      }
  
      @Test
      public void testNestedStaticEnum() throws Exception {
          final String[] expected = {
              "12:5: " + getCheckMessage(MSG_KEY, "static"),
              "16:9: " + getCheckMessage(MSG_KEY, "static"),
              "20:9: " + getCheckMessage(MSG_KEY, "static"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierStaticModifierInNestedEnum.java"),
              expected);
      }
  
      @Test
      public void testFinalInAnonymousClass()
              throws Exception {
          final String[] expected = {
              "22:20: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInAnonymousClass.java"),
              expected);
      }
  
      @Test
      public void testFinalInTryWithResource() throws Exception {
          final String[] expected = {
              "38:14: " + getCheckMessage(MSG_KEY, "final"),
              "43:14: " + getCheckMessage(MSG_KEY, "final"),
              "44:17: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInTryWithResource.java"),
              expected);
      }
  
      @Test
      public void testFinalInAbstractMethods() throws Exception {
          final String[] expected = {
              "12:33: " + getCheckMessage(MSG_KEY, "final"),
              "16:49: " + getCheckMessage(MSG_KEY, "final"),
              "19:17: " + getCheckMessage(MSG_KEY, "final"),
              "24:24: " + getCheckMessage(MSG_KEY, "final"),
              "33:33: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInAbstractMethods.java"),
              expected);
      }
  
      @Test
      public void testEnumMethods() throws Exception {
          final String[] expected = {
              "15:16: " + getCheckMessage(MSG_KEY, "final"),
              "30:16: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInEnumMethods.java"), expected);
      }
  
      @Test
      public void testEnumStaticMethodsInPublicClass() throws Exception {
          final String[] expected = {
              "20:23: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierFinalInEnumStaticMethods.java"), expected);
      }
  
      @Test
      public void testAnnotationOnEnumConstructor() throws Exception {
          final String[] expected = {
              "22:5: " + getCheckMessage(MSG_KEY, "private"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierAnnotationOnEnumConstructor.java"),
                  expected);
      }
  
      @Test
      public void testPrivateMethodInPrivateClass() throws Exception {
          final String[] expected = {
              "13:17: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierPrivateMethodInPrivateClass.java"),
                  expected);
      }
  
      @Test
      public void testTryWithResourcesBlock() throws Exception {
          final String[] expected = {
              "18:19: " + getCheckMessage(MSG_KEY, "final"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputRedundantModifierTryWithResources.java"),
                  expected);
      }
  
      @Test
      public void testNestedDef() throws Exception {
          final String[] expected = {
              "10:5: " + getCheckMessage(MSG_KEY, "public"),
              "11:5: " + getCheckMessage(MSG_KEY, "static"),
              "12:5: " + getCheckMessage(MSG_KEY, "public"),
              "12:12: " + getCheckMessage(MSG_KEY, "static"),
              "13:5: " + getCheckMessage(MSG_KEY, "static"),
              "13:12: " + getCheckMessage(MSG_KEY, "public"),
              "16:9: " + getCheckMessage(MSG_KEY, "public"),
              "19:5: " + getCheckMessage(MSG_KEY, "public"),
              "19:12: " + getCheckMessage(MSG_KEY, "static"),
              "22:5: " + getCheckMessage(MSG_KEY, "public"),
              "22:12: " + getCheckMessage(MSG_KEY, "abstract"),
              "22:21: " + getCheckMessage(MSG_KEY, "static"),
              "26:1: " + getCheckMessage(MSG_KEY, "abstract"),
              "28:5: " + getCheckMessage(MSG_KEY, "public"),
              "28:12: " + getCheckMessage(MSG_KEY, "static"),
              "32:9: " + getCheckMessage(MSG_KEY, "public"),
              "32:16: " + getCheckMessage(MSG_KEY, "static"),
              "34:13: " + getCheckMessage(MSG_KEY, "public"),
              "34:20: " + getCheckMessage(MSG_KEY, "static"),
              "37:13: " + getCheckMessage(MSG_KEY, "public"),
              "37:20: " + getCheckMessage(MSG_KEY, "static"),
              "40:13: " + getCheckMessage(MSG_KEY, "public"),
              "40:20: " + getCheckMessage(MSG_KEY, "static"),
          };
          verifyWithInlineConfigParser(getPath(
                  "InputRedundantModifierNestedDef.java"), expected);
      }
  
      @Test
      public void testRecords() throws Exception {
          final String[] expected = {
              "12:5: " + getCheckMessage(MSG_KEY, "static"),
              "16:9: " + getCheckMessage(MSG_KEY, "final"),
              "16:15: " + getCheckMessage(MSG_KEY, "static"),
              "21:9: " + getCheckMessage(MSG_KEY, "static"),
              "27:9: " + getCheckMessage(MSG_KEY, "final"),
              "27:15: " + getCheckMessage(MSG_KEY, "static"),
              "32:13: " + getCheckMessage(MSG_KEY, "static"),
              "38:1: " + getCheckMessage(MSG_KEY, "final"),
              "40:5: " + getCheckMessage(MSG_KEY, "final"),
              "43:5: " + getCheckMessage(MSG_KEY, "static"),
              "47:9: " + getCheckMessage(MSG_KEY, "final"),
              "47:15: " + getCheckMessage(MSG_KEY, "static"),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputRedundantModifierRecords.java"), expected);
      }
  }
  