1 /** 2 * Copyright (c) 2008, http://www.snakeyaml.org 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package org.yaml.snakeyaml.types; 17 18 import java.util.ArrayList; 19 import java.util.HashMap; 20 import java.util.List; 21 import java.util.Map; 22 23 import org.yaml.snakeyaml.DumperOptions; 24 import org.yaml.snakeyaml.DumperOptions.FlowStyle; 25 import org.yaml.snakeyaml.Yaml; 26 import org.yaml.snakeyaml.nodes.Node; 27 import org.yaml.snakeyaml.nodes.Tag; 28 import org.yaml.snakeyaml.representer.Represent; 29 import org.yaml.snakeyaml.representer.Representer; 30 31 /** 32 * @see <a href="http://yaml.org/type/null.html"></a> 33 */ 34 public class NullTagTest extends AbstractTest { 35 36 public void testNull() { 37 assertNull("Got: '" + load("---\n") + "'", load("---\n")); 38 assertNull(load("---\n...")); 39 assertNull(load("---\n...\n")); 40 assertNull(load("\n")); 41 assertNull(load("")); 42 assertNull(load(" ")); 43 assertNull(load("~")); 44 assertNull(load("---\n~")); 45 assertNull(load("null")); 46 assertNull(load("Null")); 47 assertNull(load("NULL")); 48 assertNull(getMapValue("empty:\n", "empty")); 49 assertNull(getMapValue("canonical: ~", "canonical")); 50 assertNull(getMapValue("english: null", "english")); 51 assertNull(getMapValue("english: Null", "english")); 52 assertNull(getMapValue("english: NULL", "english")); 53 assertEquals("null key", getMapValue("~: null key\n", null)); 54 } 55 56 @SuppressWarnings("unchecked") 57 public void testSequenceNull() { 58 String input = "---\n# This sequence has five\n# entries, two have values.\nsparse:\n - ~\n - 2nd entry\n -\n - 4th entry\n - Null\n"; 59 List<String> parsed = (List<String>) getMapValue(input, "sparse"); 60 assertEquals(5, parsed.size()); 61 assertNull(parsed.get(0)); 62 assertEquals("2nd entry", parsed.get(1)); 63 assertNull("Got: '" + parsed.get(2) + "'", parsed.get(2)); 64 assertEquals("4th entry", parsed.get(3)); 65 assertNull(parsed.get(4)); 66 } 67 68 public void testNullInMap() { 69 String input = "key1: null\n~: value1"; 70 Map<String, Object> parsed = getMap(input); 71 assertEquals(2, parsed.size()); 72 assertTrue(parsed.containsKey(null)); 73 Object value1 = parsed.get(null); 74 assertEquals("value1", value1); 75 // 76 assertNull(parsed.get("key1")); 77 // 78 assertFalse(getMap("key2: value2").containsKey(null)); 79 } 80 81 public void testNullShorthand() { 82 assertNull(getMapValue("nothing: !!null null", "nothing")); 83 } 84 85 public void testNullTag() { 86 assertNull(getMapValue("nothing: !<tag:yaml.org,2002:null> null", "nothing")); 87 } 88 89 public void testNullOut() { 90 String output = dump(null); 91 assertEquals("null\n", output); 92 } 93 94 public void testNullOutAsEmpty() { 95 Yaml yaml = new Yaml(new NullRepresenter()); 96 String output = yaml.dump(null); 97 assertEquals("", output); 98 } 99 100 /** 101 * test flow style 102 */ 103 public void testNullOutAsEmpty2() { 104 Yaml yaml = new Yaml(new NullRepresenter()); 105 Map<String, String> map = new HashMap<String, String>(); 106 map.put("aaa", "foo"); 107 map.put("bbb", null); 108 String output = yaml.dump(map); 109 assertEquals("{aaa: foo, bbb: !!null ''}\n", output); 110 } 111 112 /** 113 * test block style 114 */ 115 public void testBoolOutAsEmpty3() { 116 DumperOptions options = new DumperOptions(); 117 options.setDefaultFlowStyle(FlowStyle.BLOCK); 118 Yaml yaml = new Yaml(new NullRepresenter(), options); 119 Map<String, String> map = new HashMap<String, String>(); 120 map.put("aaa", "foo"); 121 map.put("bbb", null); 122 String output = yaml.dump(map); 123 assertEquals("aaa: foo\nbbb:\n", output); 124 } 125 126 private class NullRepresenter extends Representer { 127 public NullRepresenter() { 128 super(); 129 // null representer is exceptional and it is stored as an instance 130 // variable. 131 this.nullRepresenter = new RepresentNull(); 132 } 133 134 private class RepresentNull implements Represent { 135 public Node representData(Object data) { 136 // possible values are here http://yaml.org/type/null.html 137 return representScalar(Tag.NULL, ""); 138 } 139 } 140 } 141 142 public void testNoAnchors() { 143 List<String> list = new ArrayList<String>(3); 144 list.add(null); 145 list.add("value"); 146 list.add(null); 147 Yaml yaml = new Yaml(); 148 String output = yaml.dump(list); 149 assertEquals("Null values must not get anchors and aliases.", "[null, value, null]\n", 150 output); 151 } 152 } 153
