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.utils;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.AbstractPathTestSupport.addEndOfLine;
  import static com.puppycrawl.tools.checkstyle.internal.utils.TestUtil.isUtilsClassHasPrivateConstructor;
  import static com.puppycrawl.tools.checkstyle.utils.XpathUtil.getTextAttributeValue;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.util.List;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.io.TempDir;
  
  import com.puppycrawl.tools.checkstyle.DetailAstImpl;
  import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.xpath.AbstractNode;
  import com.puppycrawl.tools.checkstyle.xpath.RootNode;
  
  public class XpathUtilTest {
  
      @TempDir
      public File tempFolder;
  
      @Test
      public void testIsProperUtilsClass() throws ReflectiveOperationException {
          assertWithMessage("Constructor is not private")
                  .that(isUtilsClassHasPrivateConstructor(XpathUtil.class))
                  .isTrue();
      }
  
      @Test
      public void testSupportsTextAttribute() {
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.IDENT)))
                  .isTrue();
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.NUM_INT)))
                  .isTrue();
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.STRING_LITERAL)))
                  .isTrue();
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.CHAR_LITERAL)))
                  .isTrue();
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.NUM_DOUBLE)))
                  .isTrue();
          assertWithMessage("Should return false for unsupported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.VARIABLE_DEF)))
                  .isFalse();
          assertWithMessage("Should return false for unsupported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.OBJBLOCK)))
                  .isFalse();
          assertWithMessage("Should return true for supported token types")
                  .that(XpathUtil.supportsTextAttribute(createDetailAST(TokenTypes.LITERAL_CHAR)))
                  .isFalse();
      }
  
      @Test
      public void testGetValue() {
          assertWithMessage("Returned value differs from expected")
              .that(getTextAttributeValue(
                  createDetailAST(TokenTypes.STRING_LITERAL, "\"HELLO WORLD\"")))
              .isEqualTo("HELLO WORLD");
          assertWithMessage("Returned value differs from expected")
              .that(getTextAttributeValue(createDetailAST(TokenTypes.NUM_INT, "123")))
              .isEqualTo("123");
          assertWithMessage("Returned value differs from expected")
              .that(getTextAttributeValue(createDetailAST(TokenTypes.IDENT, "HELLO WORLD")))
              .isEqualTo("HELLO WORLD");
          assertWithMessage("Returned value differs from expected")
              .that(getTextAttributeValue(createDetailAST(TokenTypes.STRING_LITERAL, "HELLO WORLD")))
              .isNotEqualTo("HELLO WORLD");
      }
  
      @Test
      public void testPrintXpathNotComment() throws Exception {
          final String fileContent = "class Test { public void method() {int a = 5;}}";
          final File file = File.createTempFile("junit", null, tempFolder);
          Files.write(file.toPath(), fileContent.getBytes(StandardCharsets.UTF_8));
          final String expected = addEndOfLine(
              "COMPILATION_UNIT -> COMPILATION_UNIT [1:0]",
              "`--CLASS_DEF -> CLASS_DEF [1:0]",
              "    `--OBJBLOCK -> OBJBLOCK [1:11]",
              "        |--METHOD_DEF -> METHOD_DEF [1:13]",
              "        |   `--SLIST -> { [1:34]",
              "        |       |--VARIABLE_DEF -> VARIABLE_DEF [1:35]",
              "        |       |   |--IDENT -> a [1:39]");
          final String result = XpathUtil.printXpathBranch(
              "//CLASS_DEF//METHOD_DEF//VARIABLE_DEF//IDENT", file);
          assertWithMessage("Branch string is different")
              .that(result)
              .isEqualTo(expected);
      }
  
      @Test
      public void testPrintXpathComment() throws Exception {
          final String fileContent = "class Test { /* comment */ }";
          final File file = File.createTempFile("junit", null, tempFolder);
          Files.write(file.toPath(), fileContent.getBytes(StandardCharsets.UTF_8));
          final String expected = addEndOfLine(
              "COMPILATION_UNIT -> COMPILATION_UNIT [1:0]",
              "`--CLASS_DEF -> CLASS_DEF [1:0]",
              "    `--OBJBLOCK -> OBJBLOCK [1:11]",
              "        |--BLOCK_COMMENT_BEGIN -> /* [1:13]");
          final String result = XpathUtil.printXpathBranch(
              "//CLASS_DEF//BLOCK_COMMENT_BEGIN", file);
          assertWithMessage("Branch string is different")
              .that(result)
              .isEqualTo(expected);
      }
  
      @Test
      public void testPrintXpathTwo() throws Exception {
          final String fileContent = "class Test { public void method() {int a = 5; int b = 5;}}";
          final File file = File.createTempFile("junit", null, tempFolder);
          Files.write(file.toPath(), fileContent.getBytes(StandardCharsets.UTF_8));
          final String expected = addEndOfLine(
              "COMPILATION_UNIT -> COMPILATION_UNIT [1:0]",
              "`--CLASS_DEF -> CLASS_DEF [1:0]",
              "    `--OBJBLOCK -> OBJBLOCK [1:11]",
              "        |--METHOD_DEF -> METHOD_DEF [1:13]",
              "        |   `--SLIST -> { [1:34]",
              "        |       |--VARIABLE_DEF -> VARIABLE_DEF [1:35]",
              "        |       |   |--IDENT -> a [1:39]",
              "---------",
              "COMPILATION_UNIT -> COMPILATION_UNIT [1:0]",
              "`--CLASS_DEF -> CLASS_DEF [1:0]",
              "    `--OBJBLOCK -> OBJBLOCK [1:11]",
              "        |--METHOD_DEF -> METHOD_DEF [1:13]",
              "        |   `--SLIST -> { [1:34]",
              "        |       |--VARIABLE_DEF -> VARIABLE_DEF [1:46]",
              "        |       |   |--IDENT -> b [1:50]");
          final String result = XpathUtil.printXpathBranch(
              "//CLASS_DEF//METHOD_DEF//VARIABLE_DEF//IDENT", file);
          assertWithMessage("Branch string is different")
              .that(result)
              .isEqualTo(expected);
      }
  
      @Test
      public void testInvalidXpath() throws IOException {
          final String fileContent = "class Test { public void method() {int a = 5; int b = 5;}}";
          final File file = File.createTempFile("junit", null, tempFolder);
          Files.write(file.toPath(), fileContent.getBytes(StandardCharsets.UTF_8));
          final String invalidXpath = "\\//CLASS_DEF"
                  + "//METHOD_DEF//VARIABLE_DEF//IDENT";
          try {
              XpathUtil.printXpathBranch(invalidXpath, file);
              assertWithMessage("Should end with exception").fail();
          }
          catch (CheckstyleException ex) {
              final String expectedMessage =
                  "Error during evaluation for xpath: " + invalidXpath
                      + ", file: " + file.getCanonicalPath();
              assertWithMessage("Exception message is different")
                  .that(ex.getMessage())
                  .isEqualTo(expectedMessage);
          }
      }
  
      @Test
      public void testCreateChildren() {
          final DetailAstImpl rootAst = new DetailAstImpl();
          final DetailAstImpl elementAst = new DetailAstImpl();
          rootAst.addChild(elementAst);
          final RootNode rootNode = new RootNode(rootAst);
          final List<AbstractNode> children =
                  XpathUtil.createChildren(rootNode, rootNode, elementAst);
  
          assertWithMessage("Expected one child node")
                  .that(children)
                  .hasSize(1);
          assertWithMessage("Node depth should be 1")
                  .that(children.get(0).getDepth())
                  .isEqualTo(1);
      }
  
      private static DetailAST createDetailAST(int type) {
          final DetailAstImpl detailAST = new DetailAstImpl();
          detailAST.setType(type);
          return detailAST;
      }
  
      private static DetailAST createDetailAST(int type, String text) {
          final DetailAstImpl detailAST = new DetailAstImpl();
          detailAST.setType(type);
          detailAST.setText(text);
          return detailAST;
      }
  }
  