test/java/util/Collections/EmptyCollectionSerialization.java

rev 7291 : 7129185: Add Collections.{checked|empty|unmodifiable}Navigable{Map|Set}
Reviewed-by: dmocek, martin

*** 21,37 ****
   * questions.
   */
  
  /*
   * @test
!  * @bug     4684279
   * @summary Empty utility collections should be singletons
   * @author  Josh Bloch
   */
  
  import java.util.*;
  import java.io.*;
  
  public class EmptyCollectionSerialization {
      private static Object patheticDeepCopy(Object o) throws Exception {
          // Serialize
          ByteArrayOutputStream bos = new ByteArrayOutputStream();
--- 21,44 ----
   * questions.
   */
  
  /*
   * @test
!  * @bug     4684279 7129185
   * @summary Empty utility collections should be singletons
   * @author  Josh Bloch
+  * @run testng EmptyCollectionSerialization
   */
  
  import java.util.*;
+ import java.util.function.Supplier;
  import java.io.*;
+ import org.testng.annotations.Test;
+ import org.testng.annotations.DataProvider;
+ 
+ import static org.testng.Assert.fail;
+ import static org.testng.Assert.assertSame;
  
  public class EmptyCollectionSerialization {
      private static Object patheticDeepCopy(Object o) throws Exception {
          // Serialize
          ByteArrayOutputStream bos = new ByteArrayOutputStream();
*** 43,60 ****
          InputStream is = new ByteArrayInputStream(serializedForm);
          ObjectInputStream ois = new ObjectInputStream(is);
          return ois.readObject();
      }
  
!     private static boolean isSingleton(Object o) throws Exception {
!         return patheticDeepCopy(o) == o;
      }
  
!     public static void main(String[] args) throws Exception {
!         if (!isSingleton(Collections.EMPTY_SET))
!             throw new Exception("EMPTY_SET");
!         if (!isSingleton(Collections.EMPTY_LIST))
!             throw new Exception("EMPTY_LIST");
!         if (!isSingleton(Collections.EMPTY_MAP))
!             throw new Exception("EMPTY_MAP");
      }
  }
--- 50,93 ----
          InputStream is = new ByteArrayInputStream(serializedForm);
          ObjectInputStream ois = new ObjectInputStream(is);
          return ois.readObject();
      }
  
!     @Test(dataProvider="SerializableSingletons")
!     public static void serializableSingletons(String description, Supplier<Object> o) {
!         try {
!             assertSame(patheticDeepCopy(o.get()), o.get(), description + ": not a singleton");
!         } catch(Exception all) {
!             fail(description + ": Unexpected Exception", all);
!         }
!     }
! 
!     @DataProvider(name = "SerializableSingletons", parallel = true)
!     public static Iterator<Object[]> navigableMapProvider() {
!         return makeSingletons().iterator();
      }
  
!     public static Collection<Object[]> makeSingletons() {
!         return Arrays.asList(
!             new Object[]{"Collections.EMPTY_LIST",
!                 (Supplier) () -> {return Collections.EMPTY_LIST;}},
!             new Object[]{"Collections.EMPTY_MAP",
!                 (Supplier) () -> {return Collections.EMPTY_MAP;}},
!             new Object[]{"Collections.EMPTY_SET",
!                 (Supplier) () -> {return Collections.EMPTY_SET;}},
!             new Object[]{"Collections.singletonMap()",
!                 (Supplier) () -> {return Collections.emptyList();}},
!             new Object[]{"Collections.emptyMap()",
!                 (Supplier) () -> {return Collections.emptyMap();}},
!             new Object[]{"Collections.emptySet()",
!                 (Supplier) () -> {return Collections.emptySet();}},
!             new Object[]{"Collections.emptySortedSet()",
!                 (Supplier) () -> {return Collections.emptySortedSet();}},
!             new Object[]{"Collections.emptySortedMap()",
!                 (Supplier) () -> {return Collections.emptySortedMap();}},
!             new Object[]{"Collections.emptyNavigableSet()",
!                 (Supplier) () -> {return Collections.emptyNavigableSet();}},
!             new Object[]{"Collections.emptyNavigableMap()",
!                 (Supplier) () -> {return Collections.emptyNavigableMap();}}
!             );
      }
  }