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;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  public abstract class AbstractPathTestSupport {
  
      // we are using positive lookahead here, to convert \r\n to \n
      // and \\r\\n to \\n (for parse tree dump files),
      // by replacing the full match with the empty string
      private static final String CR_FOLLOWED_BY_LF_REGEX = "(?x)\\\\r(?=\\\\n)|\\r(?=\\n)";
  
      private static final String EOL = System.lineSeparator();
  
      /**
       * Returns the exact location for the package where the file is present.
       *
       * @return path for the package name for the file.
       */
      protected abstract String getPackageLocation();
  
      /**
       * Retrieves the name of the folder location for resources.
       *
       * @return The name of the folder.
       */
      protected String getResourceLocation() {
          return "test";
      }
  
      /**
       * Returns canonical path for the file with the given file name.
       * The path is formed base on the root location.
       * This implementation uses 'src/test/resources/'
       * as a root location.
       *
       * @param filename file name.
       * @return canonical path for the file name.
       * @throws IOException if I/O exception occurs while forming the path.
       */
      protected final String getPath(String filename) throws IOException {
          return new File("src/" + getResourceLocation() + "/resources/" + getPackageLocation() + "/"
                  + filename).getCanonicalPath();
      }
  
      /**
       * Returns the path for resources for the given file name.
       *
       * @param filename name of the file.
       * @return the path for resources for the given file based on its package location.
       */
      protected final String getResourcePath(String filename) {
          return "/" + getPackageLocation() + "/" + filename;
      }
  
      /**
       * Reads the contents of a file.
       *
       * @param filename the name of the file whose contents are to be read
       * @return contents of the file with all {@code \r\n} replaced by {@code \n}
       * @throws IOException if I/O exception occurs while reading
       * @noinspection RedundantThrows
       * @noinspectionreason RedundantThrows - false positive
       */
      protected static String readFile(String filename) throws IOException {
          return toLfLineEnding(Files.readString(Paths.get(filename)));
      }
  
      /**
       * Join given strings with {@link #EOL} delimiter and add EOL at the end.
       *
       * @param strings strings to join
       * @return joined strings
       */
      public static String addEndOfLine(String... strings) {
          return Stream.of(strings).collect(Collectors.joining(EOL, "", EOL));
      }
  
      /**
       * Returns a string containing "\r\n" converted to "\n" and "\\r\\n" converted to "\\n"
       * by replacing with empty string.
       *
       * @param text the text string.
       * @return the converted text string.
       */
      protected static String toLfLineEnding(String text) {
          return text.replaceAll(CR_FOLLOWED_BY_LF_REGEX, "");
      }
  
  }
  