1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @summary Unit tests for String#transform(Function<String, R> f)
  27  * @run main Transform
  28  */
  29 
  30 import java.util.function.Function;
  31 import java.util.stream.Collectors;
  32 
  33 public class Transform {
  34     public static void main(String[] args) {
  35         test1();
  36     }
  37 
  38     /*
  39      * Test String#transform(Function<? super String, ? extends R> f) functionality.
  40      */
  41     static void test1() {
  42         simpleTransform("toUpperCase", "abc", s -> s.toUpperCase());
  43         simpleTransform("toLowerCase", "ABC", s -> s.toLowerCase());
  44         simpleTransform("substring", "John Smith", s -> s.substring(0, 4));
  45 
  46         String multiline = "    This is line one\n" +
  47                            "        This is line two\n" +
  48                            "            This is line three\n";
  49         String expected = "This is line one!\n" +
  50                           "    This is line two!\n" +
  51                           "        This is line three!\n";
  52         check("multiline", multiline.transform(string -> {
  53             return string.lines()
  54                          .map(s -> s.substring(4) + "!")
  55                          .collect(Collectors.joining("\n", "", "\n"));
  56         }), expected);
  57     }
  58 
  59     static void simpleTransform(String test, String s, Function<String, String> f) {
  60         check(test, s.transform(f), f.apply(s));
  61     }
  62 
  63     static void check(String test, Object output, Object expected) {
  64         if (output != expected && (output == null || !output.equals(expected))) {
  65             System.err.println("Testing " + test + ": unexpected result");
  66             System.err.println("Output:");
  67             System.err.println(output);
  68             System.err.println("Expected:");
  69             System.err.println(expected);
  70             throw new RuntimeException();
  71         }
  72     }
  73 }