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.coding;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.checks.coding.IllegalInstantiationCheck.MSG_KEY;
  
  import java.io.File;
  import java.util.Collection;
  import java.util.List;
  import java.util.Optional;
  
  import org.junit.jupiter.api.Test;
  
  import com.google.common.collect.ImmutableMap;
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
  import com.puppycrawl.tools.checkstyle.DetailAstImpl;
  import com.puppycrawl.tools.checkstyle.JavaParser;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.internal.utils.TestUtil;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  public class IllegalInstantiationCheckTest
      extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/coding/illegalinstantiation";
      }
  
      @Test
      public void testDefault() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiationSemantic.java"), expected);
      }
  
      @Test
      public void testClasses() throws Exception {
          final String[] expected = {
              "24:21: " + getCheckMessage(MSG_KEY, "java.lang.Boolean"),
              "29:21: " + getCheckMessage(MSG_KEY, "java.lang.Boolean"),
              "36:16: " + getCheckMessage(MSG_KEY, "java.lang.Boolean"),
              "43:21: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.checks.coding."
                  + "illegalinstantiation.InputModifier"),
              "46:18: " + getCheckMessage(MSG_KEY, "java.io.File"),
              "49:21: " + getCheckMessage(MSG_KEY, "java.awt.Color"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiationSemantic2.java"), expected);
      }
  
      @Test
      public void testSameClassNameAsJavaLang() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiationSameClassNameJavaLang.java"),
                  expected);
      }
  
      @Test
      public void testJava8() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiation.java"),
                  expected);
      }
  
      @Test
      public void testNoPackage() throws Exception {
          final String[] expected = {
              "10:20: " + getCheckMessage(MSG_KEY, "java.lang.Boolean"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiationNoPackage.java"), expected);
      }
  
      @Test
      public void testJavaLangPackage() throws Exception {
          final String[] expected = {
              "13:19: " + getCheckMessage(MSG_KEY, "java.lang.Boolean"),
              "21:20: " + getCheckMessage(MSG_KEY, "java.lang.String"),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputIllegalInstantiationLang.java"),
                  expected);
      }
  
      @Test
      public void testWrongPackage() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputIllegalInstantiationLang2.java"),
                  expected);
      }
  
      @Test
      public void testJavaLangPackage3() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputIllegalInstantiationLang3.java"),
                  expected);
      }
  
      @Test
      public void testNameSimilarToStandardClass() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
              getPath("InputIllegalInstantiationNameSimilarToStandardClasses.java"),
              expected);
      }
  
      @Test
      public void testTokensNotNull() {
          final IllegalInstantiationCheck check = new IllegalInstantiationCheck();
          assertWithMessage("Acceptable tokens should not be null")
              .that(check.getAcceptableTokens())
              .isNotNull();
          assertWithMessage("Default tokens should not be null")
              .that(check.getDefaultTokens())
              .isNotNull();
          assertWithMessage("Required tokens should not be null")
              .that(check.getRequiredTokens())
              .isNotNull();
      }
  
      @Test
      public void testImproperToken() {
          final IllegalInstantiationCheck check = new IllegalInstantiationCheck();
  
          final DetailAstImpl lambdaAst = new DetailAstImpl();
          lambdaAst.setType(TokenTypes.LAMBDA);
  
          try {
              check.visitToken(lambdaAst);
              assertWithMessage("IllegalArgumentException is expected").fail();
          }
          catch (IllegalArgumentException ex) {
              // it is OK
          }
      }
  
      /**
       * We cannot reproduce situation when visitToken is called and leaveToken is not.
       * So, we have to use reflection to be sure that even in such situation
       * state of the field will be cleared.
       *
       * @throws Exception when code tested throws exception
       */
      @Test
      @SuppressWarnings("unchecked")
      public void testClearStateClassNames() throws Exception {
          final IllegalInstantiationCheck check = new IllegalInstantiationCheck();
          final DetailAST root = JavaParser.parseFile(
                  new File(getPath("InputIllegalInstantiationSemantic.java")),
                  JavaParser.Options.WITHOUT_COMMENTS);
          final Optional<DetailAST> classDef = TestUtil.findTokenInAstByPredicate(root,
              ast -> ast.getType() == TokenTypes.CLASS_DEF);
  
          assertWithMessage("Ast should contain CLASS_DEF")
                  .that(classDef.isPresent())
                  .isTrue();
          assertWithMessage("State is not cleared on beginTree")
              .that(
                  TestUtil.isStatefulFieldClearedDuringBeginTree(check, classDef.get(), "classNames",
                      classNames -> ((Collection<String>) classNames).isEmpty()))
              .isTrue();
      }
  
      /**
       * We cannot reproduce situation when visitToken is called and leaveToken is not.
       * So, we have to use reflection to be sure that even in such situation
       * state of the field will be cleared.
       *
       * @throws Exception when code tested throws exception
       */
      @Test
      public void testClearStateImports() throws Exception {
          final IllegalInstantiationCheck check = new IllegalInstantiationCheck();
          final DetailAST root = JavaParser.parseFile(new File(
                  getPath("InputIllegalInstantiationSemantic.java")),
                  JavaParser.Options.WITHOUT_COMMENTS);
          final Optional<DetailAST> importDef = TestUtil.findTokenInAstByPredicate(root,
              ast -> ast.getType() == TokenTypes.IMPORT);
  
          assertWithMessage("Ast should contain IMPORT_DEF")
                  .that(importDef.isPresent())
                  .isTrue();
          assertWithMessage("State is not cleared on beginTree")
              .that(
                  TestUtil.isStatefulFieldClearedDuringBeginTree(check, importDef.get(), "imports",
                      imports -> ((Collection<?>) imports).isEmpty()))
              .isTrue();
      }
  
      /**
       * We cannot reproduce situation when visitToken is called and leaveToken is not.
       * So, we have to use reflection to be sure that even in such situation
       * state of the field will be cleared.
       *
       * @throws Exception when code tested throws exception
       */
      @Test
      @SuppressWarnings("unchecked")
      public void testClearStateInstantiations() throws Exception {
          final IllegalInstantiationCheck check = new IllegalInstantiationCheck();
          final DetailAST root = JavaParser.parseFile(new File(
                  getNonCompilablePath("InputIllegalInstantiationLang.java")),
                  JavaParser.Options.WITHOUT_COMMENTS);
          final Optional<DetailAST> literalNew = TestUtil.findTokenInAstByPredicate(root,
              ast -> ast.getType() == TokenTypes.LITERAL_NEW);
  
          assertWithMessage("Ast should contain LITERAL_NEW")
                  .that(literalNew.isPresent())
                  .isTrue();
          assertWithMessage("State is not cleared on beginTree")
                  .that(TestUtil.isStatefulFieldClearedDuringBeginTree(check, literalNew.get(),
                          "instantiations",
                          instantiations -> ((Collection<DetailAST>) instantiations).isEmpty()))
                  .isTrue();
      }
  
      @Test
      public void testStateIsClearedOnBeginTreePackageName() throws Exception {
          final DefaultConfiguration checkConfig =
                  createModuleConfig(IllegalInstantiationCheck.class);
          checkConfig.addProperty("classes",
                  "java.lang.Boolean,com.puppycrawl.tools.checkstyle.checks.coding."
                          + "illegalinstantiation.InputIllegalInstantiationBeginTree2."
                          + "InputModifier");
          final String file1 = getPath(
                  "InputIllegalInstantiationBeginTree1.java");
          final String file2 = getPath(
                  "InputIllegalInstantiationBeginTree2.java");
          final List<String> expectedFirstInput = List.of(CommonUtil.EMPTY_STRING_ARRAY);
          final List<String> expectedSecondInput = List.of(CommonUtil.EMPTY_STRING_ARRAY);
          final File[] inputs = {new File(file1), new File(file2)};
  
          verify(createChecker(checkConfig), inputs, ImmutableMap.of(
              file1, expectedFirstInput,
              file2, expectedSecondInput));
      }
  }
  