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;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.checks.OuterTypeFilenameCheck.MSG_KEY;
  
  import java.io.File;
  import java.util.List;
  
  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.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  public class OuterTypeFilenameCheckTest extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/outertypefilename";
      }
  
      @Test
      public void testGetRequiredTokens() {
          final OuterTypeFilenameCheck checkObj = new OuterTypeFilenameCheck();
          final int[] expected = {
              TokenTypes.CLASS_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.ENUM_DEF,
              TokenTypes.ANNOTATION_DEF,
              TokenTypes.RECORD_DEF,
          };
          assertWithMessage("Required tokens array differs from expected")
                  .that(checkObj.getRequiredTokens())
                  .isEqualTo(expected);
      }
  
      @Test
      public void testGood1() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilenameIllegalTokens.java"), expected);
      }
  
      @Test
      public void testGood2() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename15Extensions.java"), expected);
      }
  
      @Test
      public void testGetAcceptableTokens() {
          final OuterTypeFilenameCheck check = new OuterTypeFilenameCheck();
          final int[] actual = check.getAcceptableTokens();
          final int[] expected = {
              TokenTypes.CLASS_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.ENUM_DEF,
              TokenTypes.ANNOTATION_DEF,
              TokenTypes.RECORD_DEF,
          };
          assertWithMessage("Acceptable tokens array differs from expected")
                  .that(actual)
                  .isEqualTo(expected);
      }
  
      @Test
      public void testNestedClass() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename1.java"), expected);
      }
  
      @Test
      public void testNestedClass2() throws Exception {
          final String[] expected = {
              "9:1: " + getCheckMessage(MSG_KEY),
          };
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename1a.java"), expected);
      }
  
      @Test
      public void testFinePublic() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename2.java"), expected);
      }
  
      @Test
      public void testPublicClassIsNotFirst() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilenameCheckPublic.java"), expected);
      }
  
      @Test
      public void testNoPublicClasses() throws Exception {
          final String[] expected = {
              "9:1: " + getCheckMessage(MSG_KEY),
          };
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilenameNoPublic.java"), expected);
      }
  
      @Test
      public void testFineDefault() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename3.java"), expected);
      }
  
      @Test
      public void testWrongDefault() throws Exception {
          final String[] expected = {
              "10:2: " + getCheckMessage(MSG_KEY),
          };
          verifyWithInlineConfigParser(
                  getPath("InputOuterTypeFilename5.java"), expected);
      }
  
      @Test
      public void testPackageAnnotation() throws Exception {
  
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("package-info.java"), expected);
      }
  
      @Test
      public void testOuterTypeFilenameRecords() throws Exception {
  
          final String[] expected = {
              "10:1: " + getCheckMessage(MSG_KEY),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputOuterTypeFilenameRecordMethodRecordDef.java"),
                  expected);
      }
  
      @Test
      public void testOuterTypeFilenameRecordsMethodRecordDef() throws Exception {
  
          final String[] expected = {
              "10:1: " + getCheckMessage(MSG_KEY),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputOuterTypeFilenameRecord.java"), expected);
      }
  
      @Test
      public void testStateIsClearedOnBeginTree2() throws Exception {
          final DefaultConfiguration checkConfig = createModuleConfig(OuterTypeFilenameCheck.class);
          final String file1 = getPath(
                  "InputOuterTypeFilenameBeginTree1.java");
          final String file2 = getPath(
                  "InputOuterTypeFilenameBeginTree2.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));
      }
  
      @Test
      public void testStateIsClearedOnBeginTree3() throws Exception {
          final DefaultConfiguration checkConfig = createModuleConfig(OuterTypeFilenameCheck.class);
          final String file1 = getPath(
                  "InputOuterTypeFilenameBeginTree1.java");
          final String file2 = getPath(
                  "InputOuterTypeFilename1a.java");
          final List<String> expectedFirstInput = List.of(CommonUtil.EMPTY_STRING_ARRAY);
          final List<String> expectedSecondInput = List.of(
                  "9:1: " + getCheckMessage(MSG_KEY)
          );
          final File[] inputs = {new File(file1), new File(file2)};
  
          verify(createChecker(checkConfig), inputs, ImmutableMap.of(
              file1, expectedFirstInput,
              file2, expectedSecondInput));
      }
  }
  