test/jdk/java/util/Optional/BasicLong.java

*** 29,39 ****
--- 29,41 ----
   * @run testng BasicLong
   */
  
  import java.util.NoSuchElementException;
  import java.util.OptionalLong;
+ import java.util.function.LongPredicate;
  import java.util.concurrent.atomic.AtomicBoolean;
+ import java.util.List;
  
  import static org.testng.Assert.*;
  import org.testng.annotations.Test;
  
  public class BasicLong {
*** 49,58 ****
--- 51,61 ----
          assertFalse(empty.equals(OptionalLong.of(UNEXPECTED)));
          assertFalse(OptionalLong.of(UNEXPECTED).equals(empty));
          assertFalse(empty.equals("unexpected"));
  
          assertFalse(empty.isPresent());
+         assertTrue(empty.isEmpty());
          assertEquals(empty.hashCode(), 0);
          assertEquals(empty.orElse(UNEXPECTED), UNEXPECTED);
          assertEquals(empty.orElseGet(() -> UNEXPECTED), UNEXPECTED);
  
          assertThrows(NoSuchElementException.class, () -> empty.getAsLong());
*** 124,129 ****
--- 127,148 ----
  
      @Test(groups = "unit")
      public void testStreamPresent() {
          assertEquals(OptionalLong.of(LONGVAL).stream().toArray(), new long[] { LONGVAL });
      }
+ 
+     @Test(groups = "unit")
+     public void testIsEmpty() {
+         OptionalLong empty = OptionalLong.empty();
+         assertTrue(empty.isEmpty());
+         OptionalLong present = OptionalLong.of(LONGVAL);
+         assertFalse(present.isEmpty());
+         var longList = List.of(1L, 2L, 3L, 4L, 5L);
+         LongPredicate isPositiveNumber = x -> x > 0;
+         LongPredicate isNegativeNumber = x -> x < 0;
+         OptionalLong positiveNumber = longList.stream().mapToLong(Long::longValue).filter(isPositiveNumber).findAny();
+         OptionalLong negativeNumber = longList.stream().mapToLong(Long::longValue).filter(isNegativeNumber).findAny();
+         assertFalse(positiveNumber.isEmpty());
+         assertTrue(negativeNumber.isEmpty());
+     }
+ 
  }