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test/jdk/java/util/List/ListFactories.java

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rev 48431 : 8193128: Reduce number of implementation classes returned by List/Set/Map.of()
8191418: List.of().indexOf(null) doesn't throw NullPointerException
Reviewed-by: smarks, jrose, martin, plevart


   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 import java.io.ByteArrayInputStream;
  25 import java.io.ByteArrayOutputStream;
  26 import java.io.IOException;
  27 import java.io.ObjectInputStream;
  28 import java.io.ObjectOutputStream;

  29 import java.util.ArrayList;
  30 import java.util.Arrays;
  31 import java.util.Collections;
  32 import java.util.Iterator;
  33 import java.util.List;
  34 
  35 import org.testng.annotations.DataProvider;
  36 import org.testng.annotations.Test;
  37 
  38 import static java.util.Arrays.asList;
  39 
  40 import static org.testng.Assert.assertEquals;
  41 import static org.testng.Assert.assertFalse;
  42 import static org.testng.Assert.assertNotEquals;
  43 import static org.testng.Assert.assertNotSame;
  44 import static org.testng.Assert.assertSame;
  45 import static org.testng.Assert.assertTrue;
  46 import static org.testng.Assert.fail;
  47 
  48 /*


  55 public class ListFactories {
  56 
  57     static final int NUM_STRINGS = 20; // should be larger than the largest fixed-arg overload
  58     static final String[] stringArray;
  59     static {
  60         String[] sa = new String[NUM_STRINGS];
  61         for (int i = 0; i < NUM_STRINGS; i++) {
  62             sa[i] = String.valueOf((char)('a' + i));
  63         }
  64         stringArray = sa;
  65     }
  66 
  67     // returns array of [actual, expected]
  68     static Object[] a(List<String> act, List<String> exp) {
  69         return new Object[] { act, exp };
  70     }
  71 
  72     @DataProvider(name="empty")
  73     public Iterator<Object[]> empty() {
  74         return Collections.singletonList(
  75             a(List.of(), Collections.emptyList())
  76         ).iterator();
  77     }
  78 
  79     @DataProvider(name="nonempty")
  80     public Iterator<Object[]> nonempty() {
  81         return asList(
  82             a(List.of("a"),
  83                asList("a")),
  84             a(List.of("a", "b"),
  85                asList("a", "b")),
  86             a(List.of("a", "b", "c"),
  87                asList("a", "b", "c")),
  88             a(List.of("a", "b", "c", "d"),
  89                asList("a", "b", "c", "d")),
  90             a(List.of("a", "b", "c", "d", "e"),
  91                asList("a", "b", "c", "d", "e")),
  92             a(List.of("a", "b", "c", "d", "e", "f"),
  93                asList("a", "b", "c", "d", "e", "f")),
  94             a(List.of("a", "b", "c", "d", "e", "f", "g"),
  95                asList("a", "b", "c", "d", "e", "f", "g")),
  96             a(List.of("a", "b", "c", "d", "e", "f", "g", "h"),
  97                asList("a", "b", "c", "d", "e", "f", "g", "h")),
  98             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i"),
  99                asList("a", "b", "c", "d", "e", "f", "g", "h", "i")),
 100             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i", "j"),
 101                asList("a", "b", "c", "d", "e", "f", "g", "h", "i", "j")),
 102             a(List.of(stringArray),
 103                asList(stringArray))
 104         ).iterator();
 105     }
 106 






























 107     @DataProvider(name="all")
 108     public Iterator<Object[]> all() {
 109         List<Object[]> all = new ArrayList<>();
 110         empty().forEachRemaining(all::add);
 111         nonempty().forEachRemaining(all::add);









 112         return all.iterator();
 113     }
 114 
 115     @Test(dataProvider="all", expectedExceptions=UnsupportedOperationException.class)
 116     public void cannotAddLast(List<String> act, List<String> exp) {
 117         act.add("x");
 118     }
 119 
 120     @Test(dataProvider="all", expectedExceptions=UnsupportedOperationException.class)
 121     public void cannotAddFirst(List<String> act, List<String> exp) {
 122         act.add(0, "x");
 123     }
 124 
 125     @Test(dataProvider="nonempty", expectedExceptions=UnsupportedOperationException.class)
 126     public void cannotRemove(List<String> act, List<String> exp) {
 127         act.remove(0);
 128     }
 129 
 130     @Test(dataProvider="nonempty", expectedExceptions=UnsupportedOperationException.class)
 131     public void cannotSet(List<String> act, List<String> exp) {


 195     @Test(expectedExceptions=NullPointerException.class)
 196     public void nullDisallowedN() {
 197         String[] array = stringArray.clone();
 198         array[0] = null;
 199         List.of(array);
 200     }
 201 
 202     @Test(expectedExceptions=NullPointerException.class)
 203     public void nullArrayDisallowed() {
 204         List.of((Object[])null);
 205     }
 206 
 207     @Test
 208     public void ensureArrayCannotModifyList() {
 209         String[] array = stringArray.clone();
 210         List<String> list = List.of(array);
 211         array[0] = "xyzzy";
 212         assertEquals(list, Arrays.asList(stringArray));
 213     }
 214 
 215     @Test(dataProvider="all")























































 216     public void serialEquality(List<String> act, List<String> exp) {
 217         // assume that act.equals(exp) tested elsewhere
 218         List<String> copy = serialClone(act);
 219         assertEquals(act, copy);
 220         assertEquals(copy, exp);
 221     }
 222 
 223     @SuppressWarnings("unchecked")
 224     static <T> T serialClone(T obj) {
 225         try {
 226             ByteArrayOutputStream baos = new ByteArrayOutputStream();
 227             try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
 228                 oos.writeObject(obj);
 229             }
 230             ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
 231             ObjectInputStream ois = new ObjectInputStream(bais);
 232             return (T) ois.readObject();
 233         } catch (IOException | ClassNotFoundException e) {
 234             throw new AssertionError(e);
 235         }




   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 import java.io.ByteArrayInputStream;
  25 import java.io.ByteArrayOutputStream;
  26 import java.io.IOException;
  27 import java.io.ObjectInputStream;
  28 import java.io.ObjectOutputStream;
  29 import java.io.Serializable;
  30 import java.util.ArrayList;
  31 import java.util.Arrays;
  32 import java.util.Collections;
  33 import java.util.Iterator;
  34 import java.util.List;
  35 
  36 import org.testng.annotations.DataProvider;
  37 import org.testng.annotations.Test;
  38 
  39 import static java.util.Arrays.asList;
  40 
  41 import static org.testng.Assert.assertEquals;
  42 import static org.testng.Assert.assertFalse;
  43 import static org.testng.Assert.assertNotEquals;
  44 import static org.testng.Assert.assertNotSame;
  45 import static org.testng.Assert.assertSame;
  46 import static org.testng.Assert.assertTrue;
  47 import static org.testng.Assert.fail;
  48 
  49 /*


  56 public class ListFactories {
  57 
  58     static final int NUM_STRINGS = 20; // should be larger than the largest fixed-arg overload
  59     static final String[] stringArray;
  60     static {
  61         String[] sa = new String[NUM_STRINGS];
  62         for (int i = 0; i < NUM_STRINGS; i++) {
  63             sa[i] = String.valueOf((char)('a' + i));
  64         }
  65         stringArray = sa;
  66     }
  67 
  68     // returns array of [actual, expected]
  69     static Object[] a(List<String> act, List<String> exp) {
  70         return new Object[] { act, exp };
  71     }
  72 
  73     @DataProvider(name="empty")
  74     public Iterator<Object[]> empty() {
  75         return Collections.singletonList(
  76             a(List.of(), asList())
  77         ).iterator();
  78     }
  79 
  80     @DataProvider(name="nonempty")
  81     public Iterator<Object[]> nonempty() {
  82         return asList(
  83             a(List.of("a"),
  84                asList("a")),
  85             a(List.of("a", "b"),
  86                asList("a", "b")),
  87             a(List.of("a", "b", "c"),
  88                asList("a", "b", "c")),
  89             a(List.of("a", "b", "c", "d"),
  90                asList("a", "b", "c", "d")),
  91             a(List.of("a", "b", "c", "d", "e"),
  92                asList("a", "b", "c", "d", "e")),
  93             a(List.of("a", "b", "c", "d", "e", "f"),
  94                asList("a", "b", "c", "d", "e", "f")),
  95             a(List.of("a", "b", "c", "d", "e", "f", "g"),
  96                asList("a", "b", "c", "d", "e", "f", "g")),
  97             a(List.of("a", "b", "c", "d", "e", "f", "g", "h"),
  98                asList("a", "b", "c", "d", "e", "f", "g", "h")),
  99             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i"),
 100                asList("a", "b", "c", "d", "e", "f", "g", "h", "i")),
 101             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i", "j"),
 102                asList("a", "b", "c", "d", "e", "f", "g", "h", "i", "j")),
 103             a(List.of(stringArray),
 104                asList(stringArray))
 105         ).iterator();
 106     }
 107 
 108     @DataProvider(name="sublists")
 109     public Iterator<Object[]> sublists() {
 110         return asList(
 111             a(List.<String>of().subList(0,0),
 112                asList()),
 113             a(List.of("a").subList(0,0),
 114                asList("a").subList(0,0)),
 115             a(List.of("a", "b").subList(0,1),
 116                asList("a", "b").subList(0,1)),
 117             a(List.of("a", "b", "c").subList(1,3),
 118                asList("a", "b", "c").subList(1,3)),
 119             a(List.of("a", "b", "c", "d").subList(0,4),
 120                asList("a", "b", "c", "d").subList(0,4)),
 121             a(List.of("a", "b", "c", "d", "e").subList(0,3),
 122                asList("a", "b", "c", "d", "e").subList(0,3)),
 123             a(List.of("a", "b", "c", "d", "e", "f").subList(3, 5),
 124                asList("a", "b", "c", "d", "e", "f").subList(3, 5)),
 125             a(List.of("a", "b", "c", "d", "e", "f", "g").subList(0, 7),
 126                asList("a", "b", "c", "d", "e", "f", "g").subList(0, 7)),
 127             a(List.of("a", "b", "c", "d", "e", "f", "g", "h").subList(0, 0),
 128                asList("a", "b", "c", "d", "e", "f", "g", "h").subList(0, 0)),
 129             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i").subList(4, 5),
 130                asList("a", "b", "c", "d", "e", "f", "g", "h", "i").subList(4, 5)),
 131             a(List.of("a", "b", "c", "d", "e", "f", "g", "h", "i", "j").subList(1,10),
 132                asList("a", "b", "c", "d", "e", "f", "g", "h", "i", "j").subList(1,10)),
 133             a(List.of(stringArray).subList(5, NUM_STRINGS),
 134                asList(Arrays.copyOfRange(stringArray, 5, NUM_STRINGS)))
 135                 ).iterator();
 136     }
 137 
 138     @DataProvider(name="all")
 139     public Iterator<Object[]> all() {
 140         List<Object[]> all = new ArrayList<>();
 141         empty().forEachRemaining(all::add);
 142         nonempty().forEachRemaining(all::add);
 143         sublists().forEachRemaining(all::add);
 144         return all.iterator();
 145     }
 146 
 147     @DataProvider(name="nonsublists")
 148     public Iterator<Object[]> nonsublists() {
 149         List<Object[]> all = new ArrayList<>();
 150         empty().forEachRemaining(all::add);
 151         nonempty().forEachRemaining(all::add);
 152         return all.iterator();
 153     }
 154 
 155     @Test(dataProvider="all", expectedExceptions=UnsupportedOperationException.class)
 156     public void cannotAddLast(List<String> act, List<String> exp) {
 157         act.add("x");
 158     }
 159 
 160     @Test(dataProvider="all", expectedExceptions=UnsupportedOperationException.class)
 161     public void cannotAddFirst(List<String> act, List<String> exp) {
 162         act.add(0, "x");
 163     }
 164 
 165     @Test(dataProvider="nonempty", expectedExceptions=UnsupportedOperationException.class)
 166     public void cannotRemove(List<String> act, List<String> exp) {
 167         act.remove(0);
 168     }
 169 
 170     @Test(dataProvider="nonempty", expectedExceptions=UnsupportedOperationException.class)
 171     public void cannotSet(List<String> act, List<String> exp) {


 235     @Test(expectedExceptions=NullPointerException.class)
 236     public void nullDisallowedN() {
 237         String[] array = stringArray.clone();
 238         array[0] = null;
 239         List.of(array);
 240     }
 241 
 242     @Test(expectedExceptions=NullPointerException.class)
 243     public void nullArrayDisallowed() {
 244         List.of((Object[])null);
 245     }
 246 
 247     @Test
 248     public void ensureArrayCannotModifyList() {
 249         String[] array = stringArray.clone();
 250         List<String> list = List.of(array);
 251         array[0] = "xyzzy";
 252         assertEquals(list, Arrays.asList(stringArray));
 253     }
 254 
 255     @Test
 256     public void indexOf() {
 257         assertEquals(List.of("a").indexOf("a"), 0);
 258         assertEquals(List.of("a", "a").indexOf("a"), 0);
 259         assertEquals(List.of("b", "a", "a").indexOf("a"), 1);
 260         assertEquals(List.of("b", "b", "a", "a").indexOf("a"), 2);
 261         assertEquals(List.of("b", "b", "b", "a", "a").indexOf("a"), 3);
 262         assertEquals(List.of("b", "b", "b", "b", "a", "a").indexOf("a"), 4);
 263 
 264         assertEquals(List.of("a").subList(0, 1).indexOf("a"), 0);
 265         assertEquals(List.of("a", "a").subList(0, 2).indexOf("a"), 0);
 266         assertEquals(List.of("b", "a", "a").subList(0, 3).indexOf("a"), 1);
 267         assertEquals(List.of("b", "b", "a", "a").subList(0, 4).indexOf("a"), 2);
 268         assertEquals(List.of("b", "b", "b", "a", "a").subList(0, 5).indexOf("a"), 3);
 269         assertEquals(List.of("b", "b", "b", "b", "a", "a").subList(0, 6).indexOf("a"), 4);
 270 
 271         assertEquals(List.of("a").lastIndexOf("a"), 0);
 272         assertEquals(List.of("a", "a").lastIndexOf("a"), 1);
 273         assertEquals(List.of("b", "a", "a").lastIndexOf("a"), 2);
 274         assertEquals(List.of("b", "b", "a", "a").lastIndexOf("a"), 3);
 275         assertEquals(List.of("b", "b", "b", "a", "a").lastIndexOf("a"), 4);
 276         assertEquals(List.of("b", "b", "b", "b", "a", "a").lastIndexOf("a"), 5);
 277         assertEquals(List.of("c", "b", "b", "b", "a", "a").lastIndexOf("c"), 0);
 278 
 279         assertEquals(List.of("a").subList(0, 1).lastIndexOf("a"), 0);
 280         assertEquals(List.of("a", "a").subList(0, 2).lastIndexOf("a"), 1);
 281         assertEquals(List.of("b", "a", "a").subList(0, 3).lastIndexOf("a"), 2);
 282         assertEquals(List.of("b", "b", "a", "a").subList(0, 4).lastIndexOf("a"), 3);
 283         assertEquals(List.of("b", "b", "b", "a", "a").subList(0, 5).lastIndexOf("a"), 4);
 284         assertEquals(List.of("b", "b", "b", "b", "a", "a").subList(0, 6).lastIndexOf("a"), 5);
 285         assertEquals(List.of("c", "b", "b", "b", "a", "a").subList(0, 6).lastIndexOf("c"), 0);
 286     }
 287 
 288     @Test(dataProvider="all", expectedExceptions=NullPointerException.class)
 289     public void containsNullShouldThrowNPE(List<String> act, List<String> exp) {
 290         act.contains(null);
 291     }
 292 
 293     @Test(dataProvider="all", expectedExceptions=NullPointerException.class)
 294     public void indexOfNullShouldThrowNPE(List<String> act, List<String> exp) {
 295         act.indexOf(null);
 296     }
 297 
 298     @Test(dataProvider="all", expectedExceptions=NullPointerException.class)
 299     public void lastIndexOfNullShouldThrowNPE(List<String> act, List<String> exp) {
 300         act.lastIndexOf(null);
 301     }
 302 
 303     // List.of().subList views should not be Serializable
 304     @Test(dataProvider="sublists")
 305     public void isNotSerializable(List<String> act, List<String> exp) {
 306         assertFalse(act instanceof Serializable);
 307     }
 308 
 309     // ... but List.of() should be
 310     @Test(dataProvider="nonsublists")
 311     public void serialEquality(List<String> act, List<String> exp) {
 312         // assume that act.equals(exp) tested elsewhere
 313         List<String> copy = serialClone(act);
 314         assertEquals(act, copy);
 315         assertEquals(copy, exp);
 316     }
 317 
 318     @SuppressWarnings("unchecked")
 319     static <T> T serialClone(T obj) {
 320         try {
 321             ByteArrayOutputStream baos = new ByteArrayOutputStream();
 322             try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
 323                 oos.writeObject(obj);
 324             }
 325             ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
 326             ObjectInputStream ois = new ObjectInputStream(bais);
 327             return (T) ois.readObject();
 328         } catch (IOException | ClassNotFoundException e) {
 329             throw new AssertionError(e);
 330         }


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