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.grammar;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  
  import org.antlr.v4.runtime.CharStream;
  import org.antlr.v4.runtime.CharStreams;
  import org.junit.jupiter.api.Test;
  
  public class CrAwareLexerTest {
  
      @Test
      public void testConsumeCarriageReturnZeroCharPositionInLine() {
          final String text = "\r";
          final CharStream charStream = CharStreams.fromString(text);
          final CrAwareLexerSimulator lexer =
                  new CrAwareLexerSimulator(null, null, null, null);
          lexer.consume(charStream);
  
          assertWithMessage("Carriage return should reset column number.")
                  .that(lexer.getCharPositionInLine())
                  .isEqualTo(0);
      }
  
      @Test
      public void testConsumeCarriageReturnNewline() {
          final String text = "\r";
          final CharStream charStream = CharStreams.fromString(text);
          final CrAwareLexerSimulator lexer =
                  new CrAwareLexerSimulator(null, null, null, null);
          lexer.consume(charStream);
  
          assertWithMessage("Carriage return should increment line number.")
                  .that(lexer.getLine())
                  .isEqualTo(2);
      }
  
      @Test
      public void testConsumeWindowsNewlineZeroCharPositionInLine() {
          final String text = "\r\n";
          final CharStream charStream = CharStreams.fromString(text);
          final CrAwareLexerSimulator lexer =
                  new CrAwareLexerSimulator(null, null, null, null);
          lexer.consume(charStream);
          lexer.consume(charStream);
  
          assertWithMessage("Carriage return should reset column number.")
                  .that(lexer.getCharPositionInLine())
                  .isEqualTo(0);
      }
  
      @Test
      public void testConsumeWindowsNewline() {
          final String text = "\r\n";
          final CharStream charStream = CharStreams.fromString(text);
          final CrAwareLexerSimulator lexer =
                  new CrAwareLexerSimulator(null, null, null, null);
          lexer.consume(charStream);
          lexer.consume(charStream);
  
          assertWithMessage("Carriage return should increment line number.")
                  .that(lexer.getLine())
                  .isEqualTo(2);
      }
  }
  