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.xpath;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.utils.XpathUtil.getXpathItems;
  
  import java.io.File;
  import java.util.List;
  
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.AbstractPathTestSupport;
  import com.puppycrawl.tools.checkstyle.JavaParser;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import net.sf.saxon.om.AxisInfo;
  import net.sf.saxon.om.NodeInfo;
  import net.sf.saxon.tree.iter.AxisIterator;
  import net.sf.saxon.tree.iter.EmptyIterator;
  
  public class RootNodeTest extends AbstractPathTestSupport {
  
      private static RootNode rootNode;
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/xpath/xpathmapper";
      }
  
      @BeforeEach
      public void init() throws Exception {
          final File file = new File(getPath("InputXpathMapperAst.java"));
          final DetailAST rootAst = JavaParser.parseFile(file, JavaParser.Options.WITHOUT_COMMENTS);
          rootNode = new RootNode(rootAst);
      }
  
      @Test
      public void testCompareOrder() {
          try {
              rootNode.compareOrder(null);
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testXpath() throws Exception {
          final String xpath = "/";
          final List<NodeInfo> nodes = getXpathItems(xpath, rootNode);
          assertWithMessage("Invalid number of nodes")
              .that(nodes)
              .hasSize(1);
          final NodeInfo firstNode = nodes.get(0);
          assertWithMessage("Should return true, because selected node is RootNode")
                  .that(firstNode)
                  .isInstanceOf(RootNode.class);
          assertWithMessage("Result node should have same reference as expected")
              .that(rootNode)
              .isEqualTo(firstNode);
      }
  
      @Test
      public void testGetDepth() {
          assertWithMessage("Root node depth should be 0")
                  .that(rootNode.getDepth())
                  .isEqualTo(0);
      }
  
      @Test
      public void testGetTokenType() {
          assertWithMessage("Invalid token type")
              .that(rootNode.getTokenType())
              .isEqualTo(TokenTypes.COMPILATION_UNIT);
      }
  
      @Test
      public void testGetLineNumber() {
          assertWithMessage("Invalid line number")
              .that(rootNode.getLineNumber())
              .isEqualTo(1);
      }
  
      @Test
      public void testGetColumnNumber() {
          assertWithMessage("Invalid column number")
              .that(rootNode.getColumnNumber())
              .isEqualTo(0);
      }
  
      @Test
      public void testGetLocalPart() {
          assertWithMessage("Invalid local part")
              .that(rootNode.getLocalPart())
              .isEqualTo("ROOT");
      }
  
      @Test
      public void testIterate() {
          try (AxisIterator following = rootNode.iterateAxis(AxisInfo.FOLLOWING)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(following)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator followingSibling = rootNode.iterateAxis(AxisInfo.FOLLOWING_SIBLING)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(followingSibling)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator preceding = rootNode.iterateAxis(AxisInfo.PRECEDING)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(preceding)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator precedingSibling = rootNode.iterateAxis(AxisInfo.PRECEDING_SIBLING)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(precedingSibling)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator parent = rootNode.iterateAxis(AxisInfo.PARENT)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(parent)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator parentNull = rootNode.iterateAxis(AxisInfo.PARENT, null)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(parentNull)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
      }
  
      @Test
      public void testRootWithNullDetailAst() {
          final RootNode emptyRootNode = new RootNode(null);
          assertWithMessage("Empty node should not have children")
                  .that(emptyRootNode.hasChildNodes())
                  .isFalse();
  
          try (AxisIterator iterator = emptyRootNode.iterateAxis(AxisInfo.DESCENDANT)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(iterator)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
          try (AxisIterator iterator = emptyRootNode.iterateAxis(AxisInfo.CHILD)) {
              assertWithMessage("Result iterator does not match expected")
                  .that(iterator)
                  .isEqualTo(EmptyIterator.ofNodes());
          }
      }
  
      @Test
      public void testGetStringValue() {
          try {
              rootNode.getStringValue();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetAttributeValue() {
          try {
              rootNode.getAttributeValue("", "");
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetDeclaredNamespaces() {
          try {
              rootNode.getDeclaredNamespaces(null);
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testIsId() {
          try {
              rootNode.isId();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testIsIdref() {
          try {
              rootNode.isIdref();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testIsNilled() {
          try {
              rootNode.isNilled();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testIsStreamed() {
          try {
              rootNode.isStreamed();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetConfiguration() {
          try {
              rootNode.getConfiguration();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testSetSystemId() {
          try {
              rootNode.setSystemId("1");
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetSystemId() {
          try {
              rootNode.getSystemId();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetPublicId() {
          try {
              rootNode.getPublicId();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testBaseUri() {
          try {
              rootNode.getBaseURI();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testSaveLocation() {
          try {
              rootNode.saveLocation();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetStringValueCs() {
          try {
              rootNode.getUnicodeStringValue();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testFingerprint() {
          try {
              rootNode.getFingerprint();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetDisplayName() {
          try {
              rootNode.getDisplayName();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetPrefix() {
          try {
              rootNode.getPrefix();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetSchemaType() {
          try {
              rootNode.getSchemaType();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testAtomize() {
          try {
              rootNode.atomize();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGenerateId() {
          try {
              rootNode.generateId(null);
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testCopy() {
          try {
              rootNode.copy(null, -1, null);
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testGetAllNamespaces() {
          try {
              rootNode.getAllNamespaces();
              assertWithMessage("Exception is excepted").fail();
          }
          catch (UnsupportedOperationException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("Operation is not supported");
          }
      }
  
      @Test
      public void testSameNodeInfo() {
          assertWithMessage("Should return true, because object is being compared to itself")
                  .that(rootNode.isSameNodeInfo(rootNode))
                  .isTrue();
          assertWithMessage("Should return false, because object does not equal null")
                  .that(rootNode.isSameNodeInfo(null))
                  .isFalse();
      }
  }
  