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.PackageDeclarationCheck.MSG_KEY_MISMATCH;
  import static com.puppycrawl.tools.checkstyle.checks.coding.PackageDeclarationCheck.MSG_KEY_MISSING;
  
  import java.io.File;
  
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.Checker;
  import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  import de.thetaphi.forbiddenapis.SuppressForbidden;
  
  public class PackageDeclarationCheckTest extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/coding/packagedeclaration";
      }
  
      @Test
      public void testDefaultNoPackage() throws Exception {
  
          final String[] expected = {
              "8:1: " + getCheckMessage(MSG_KEY_MISSING),
          };
  
          verifyWithInlineConfigParser(
                  getPath("InputPackageDeclarationNoPackage.java"), expected);
      }
  
      @Test
      public void testDefaultWithPackage() throws Exception {
  
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getPath("InputPackageDeclarationPlain.java"), expected);
      }
  
      @Test
      public void testOnFileWithCommentOnly() throws Exception {
  
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getPath("InputPackageDeclarationWithCommentOnly.java"), expected);
      }
  
      @Test
      public void testFileForDiffDirectoryMismatch() throws Exception {
  
          final String[] expected = {
              "8:1: " + getCheckMessage(MSG_KEY_MISMATCH),
          };
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectory.java"), expected);
      }
  
      @Test
      public void testFileForDirectoryMismatchAtParent() throws Exception {
  
          final String[] expected = {
              "8:1: " + getCheckMessage(MSG_KEY_MISMATCH),
          };
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectoryAtParent.java"),
                  expected);
      }
  
      @Test
      public void testFileForDirectoryMismatchAtSubpackage() throws Exception {
  
          final String[] expected = {
              "8:1: " + getCheckMessage(MSG_KEY_MISMATCH),
          };
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectoryAtSubpackage.java"),
                  expected);
      }
  
      @Test
      public void testFileIgnoreDiffDirectoryMismatch() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectory2.java"),
                  expected);
      }
  
      @Test
      public void testFileIgnoreDirectoryMismatchAtParent() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectoryAtParent2.java"),
                  expected);
      }
  
      @Test
      public void testFileIgnoreDirectoryMismatchAtSubpackage() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationDiffDirectoryAtSubpackage2.java"),
                  expected);
      }
  
      @Test
      public void testNoPackage() throws Exception {
          final String[] expected = {
              "9:1: " + getCheckMessage(MSG_KEY_MISSING),
          };
  
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputPackageDeclarationNoPackage.java"),
                  expected);
      }
  
      @SuppressForbidden
      @Test
      public void testEmptyFile() throws Exception {
          final DefaultConfiguration checkConfig = createModuleConfig(PackageDeclarationCheck.class);
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
  
          verify(checkConfig,
                  getNonCompilablePath("InputPackageDeclarationEmptyFile.java"),
                  expected);
      }
  
      @Test
      public void testTokensNotNull() {
          final PackageDeclarationCheck check = new PackageDeclarationCheck();
          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 testBeginTreeClear() throws Exception {
          final DefaultConfiguration checkConfig =
              createModuleConfig(PackageDeclarationCheck.class);
          final String[] expected = {
              "8:1: " + getCheckMessage(MSG_KEY_MISSING),
          };
          final Checker checker = createChecker(checkConfig);
          final String fileName1 = getPath("InputPackageDeclarationPlain.java");
          final String fileName2 = getPath("InputPackageDeclarationNoPackage.java");
          final File[] files = {
              new File(fileName1),
              new File(fileName2),
          };
          verify(checker, files, fileName2, expected);
      }
  }
  