Merged for javadoc

Author: fluentfuture

mug/src/main/java/com/google/mu/util/Optionals.java

@@ -105,6 +105,16 @@ public static <C extends Collection<?>> Optional<C> nonEmpty(C collection) {
     return collection.isEmpty() ? Optional.empty() : Optional.of(collection);
   }
 
+  /**
+   * Returns {@code Optional.empty()} if {@code s} is null or empty;
+   * otherwise wraps it with {@link Optional#of}.
+   *
+   * @since 9.9.3
+   */
+  public static <S extends CharSequence> Optional<S> nonEmpty(S s) {
+    return optional(s != null && s.length() > 0, s);
+  }
+
   /**
    * If {@code a} and {@code b} are present, returns a {@code BiOptional} instance containing them;
    * otherwise returns an empty {@code BiOptional}.

mug/src/main/java/com/google/mu/util/stream/MoreStreams.java

@@ -473,12 +473,13 @@ public static <T> Stream<T> whileNotNull(Supplier<? extends T> supplier) {
   public static <T> Stream<T> withSideEffect(Stream<T> stream, Consumer<? super T> sideEffect) {
     requireNonNull(stream);
     requireNonNull(sideEffect);
-    return StreamSupport.stream(() -> withSideEffect(stream.spliterator(), sideEffect), 0, false);
+    return StreamSupport.stream(
+        () -> withSideEffect(stream.spliterator(), sideEffect), Spliterator.ORDERED, false);
   }
 
   private static <T> Spliterator<T> withSideEffect(
       Spliterator<T> spliterator, Consumer<? super T> sideEffect) {
-    return new AbstractSpliterator<T>(spliterator.estimateSize(), 0) {
+    return new AbstractSpliterator<T>(spliterator.estimateSize(), Spliterator.ORDERED) {
       @Override public boolean tryAdvance(Consumer<? super T> action) {
         return spliterator.tryAdvance(e -> {
           sideEffect.accept(e);

mug/src/test/java/com/google/mu/util/OptionalsTest.java

@@ -82,6 +82,18 @@ public class OptionalsTest {
     assertThat(Optionals.nonEmpty(asList(1))).hasValue(asList(1));
   }
 
+  @Test public void nonEmpty_nullString() {
+    assertThat(Optionals.nonEmpty("")).isEmpty();
+  }
+
+  @Test public void nonEmpty_emptyString() {
+    assertThat(Optionals.nonEmpty("")).isEmpty();
+  }
+
+  @Test public void nonEmpty_nonEmptyString() {
+    assertThat(Optionals.nonEmpty("foo")).hasValue("foo");
+  }
+
   @Test public void ifPresent_or_firstIsAbsent_secondSupplierIsPresent() {
     ifPresent(Optional.empty(), consumer::accept)
         .or(() -> ifPresent(Optional.of("left"), Optional.of("right"), action::run))
@@ -256,12 +268,14 @@ public void inOrder_bothStepsArePresent() {
         .setDefault(BiOptional.class, BiOptional.of(1, "one"))
         .ignore(Optionals.class.getMethod("optional", boolean.class, Object.class))
         .ignore(Optionals.class.getMethod("both", Optional.class, Optional.class))
+        .ignore(Optionals.class.getMethod("nonEmpty", CharSequence.class))
         .testAllPublicStaticMethods(Optionals.class);
     new NullPointerTester()
         .setDefault(Optional.class, Optional.of("foo"))
         .setDefault(OptionalInt.class, OptionalInt.of(123))
         .setDefault(OptionalLong.class, OptionalLong.of(123))
         .setDefault(OptionalDouble.class, OptionalDouble.of(123))
+        .ignore(Optionals.class.getMethod("nonEmpty", CharSequence.class))
         .setDefault(BiOptional.class, BiOptional.of(1, "one"))
         .ignore(Optionals.class.getMethod("optional", boolean.class, Object.class))
         .testAllPublicStaticMethods(Optionals.class);