Return an empty stream if passed array is empty

aNNiMON · Feb 22, 2017 · 178c6cb · 178c6cb
1 parent 5d437be
commit 178c6cb
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Showing 8 changed files with 41 additions and 1 deletion.
diff --git a/stream/src/main/java/com/annimon/stream/DoubleStream.java b/stream/src/main/java/com/annimon/stream/DoubleStream.java
@@ -61,6 +61,9 @@ public static DoubleStream of(PrimitiveIterator.OfDouble iterator) {
      */
     public static DoubleStream of(final double... values) {
         Objects.requireNonNull(values);
+        if (values.length == 0) {
+            return DoubleStream.empty();
+        }
         return new DoubleStream(new DoubleArray(values));
     }
 

diff --git a/stream/src/main/java/com/annimon/stream/IntStream.java b/stream/src/main/java/com/annimon/stream/IntStream.java
@@ -58,6 +58,9 @@ public static IntStream of(PrimitiveIterator.OfInt iterator) {
      */
     public static IntStream of(final int... values) {
         Objects.requireNonNull(values);
+        if (values.length == 0) {
+            return IntStream.empty();
+        }
         return new IntStream(new IntArray(values));
     }
 

diff --git a/stream/src/main/java/com/annimon/stream/LongStream.java b/stream/src/main/java/com/annimon/stream/LongStream.java
@@ -61,6 +61,9 @@ public static LongStream of(PrimitiveIterator.OfLong iterator) {
      */
     public static LongStream of(final long... values) {
         Objects.requireNonNull(values);
+        if (values.length == 0) {
+            return LongStream.empty();
+        }
         return new LongStream(new LongArray(values));
     }
 

diff --git a/stream/src/main/java/com/annimon/stream/Stream.java b/stream/src/main/java/com/annimon/stream/Stream.java
@@ -78,6 +78,9 @@ public static <T> Stream<T> of(Iterable<? extends T> iterable) {
      */
     public static <T> Stream<T> of(final T... elements) {
         Objects.requireNonNull(elements);
+        if (elements.length == 0) {
+            return Stream.<T>empty();
+        }
         return new Stream<T>(new ObjArray<T>(elements));
     }
 

diff --git a/stream/src/test/java/com/annimon/stream/DoubleStreamTest.java b/stream/src/test/java/com/annimon/stream/DoubleStreamTest.java
@@ -16,6 +16,7 @@
 import java.util.NoSuchElementException;
 import org.junit.Test;
 import static com.annimon.stream.test.hamcrest.DoubleStreamMatcher.assertElements;
+import static com.annimon.stream.test.hamcrest.DoubleStreamMatcher.assertIsEmpty;
 import static com.annimon.stream.test.hamcrest.DoubleStreamMatcher.elements;
 import static com.annimon.stream.test.hamcrest.DoubleStreamMatcher.isEmpty;
 import static com.annimon.stream.test.hamcrest.OptionalDoubleMatcher.hasValue;
@@ -80,6 +81,12 @@ public void testStreamOfDoublesNull() {
         DoubleStream.of((double[]) null);
     }
 
+    @Test
+    public void testStreamOfEmptyArray() {
+        DoubleStream.of(new double[0])
+                .custom(assertIsEmpty());
+    }
+
     @Test
     public void testStreamOfDouble() {
         assertThat(DoubleStream.of(1.234), elements(arrayContaining(1.234)));

diff --git a/stream/src/test/java/com/annimon/stream/IntStreamTest.java b/stream/src/test/java/com/annimon/stream/IntStreamTest.java
@@ -20,6 +20,7 @@
 import org.hamcrest.Matchers;
 import org.junit.Test;
 import static com.annimon.stream.test.hamcrest.IntStreamMatcher.assertElements;
+import static com.annimon.stream.test.hamcrest.IntStreamMatcher.assertIsEmpty;
 import static com.annimon.stream.test.hamcrest.OptionalIntMatcher.hasValue;
 import static com.annimon.stream.test.hamcrest.StreamMatcher.elements;
 import static org.hamcrest.CoreMatchers.is;
@@ -74,14 +75,20 @@ public void testStreamOfInts() {
 
         assertTrue(IntStream.of(data1).count() == 5);
         assertTrue(IntStream.of(data2).findFirst().getAsInt() == 42);
-        assertTrue(!IntStream.of(data3).findFirst().isPresent());
+        assertFalse(IntStream.of(data3).findFirst().isPresent());
     }
 
     @Test(expected = NullPointerException.class)
     public void testStreamOfIntsNull() {
         IntStream.of((int[]) null);
     }
 
+    @Test
+    public void testStreamOfEmptyArray() {
+        IntStream.of(new int[0])
+                .custom(assertIsEmpty());
+    }
+
     @Test
     public void testStreamOfInt() {
         assertTrue(IntStream.of(42).count() == 1);

diff --git a/stream/src/test/java/com/annimon/stream/LongStreamTest.java b/stream/src/test/java/com/annimon/stream/LongStreamTest.java
@@ -17,6 +17,7 @@
 import java.util.NoSuchElementException;
 import org.junit.Test;
 import static com.annimon.stream.test.hamcrest.LongStreamMatcher.assertElements;
+import static com.annimon.stream.test.hamcrest.LongStreamMatcher.assertIsEmpty;
 import static com.annimon.stream.test.hamcrest.LongStreamMatcher.elements;
 import static com.annimon.stream.test.hamcrest.LongStreamMatcher.isEmpty;
 import static com.annimon.stream.test.hamcrest.OptionalLongMatcher.hasValue;
@@ -75,6 +76,12 @@ public void testStreamOfLongsNull() {
         LongStream.of((long[]) null);
     }
 
+    @Test
+    public void testStreamOfEmptyArray() {
+        LongStream.of(new long[0])
+                .custom(assertIsEmpty());
+    }
+
     @Test
     public void testStreamOfLong() {
         assertThat(LongStream.of(1234), elements(arrayContaining(1234L)));

diff --git a/stream/src/test/java/com/annimon/stream/StreamTest.java b/stream/src/test/java/com/annimon/stream/StreamTest.java
@@ -15,6 +15,7 @@
 import com.annimon.stream.function.UnaryOperator;
 import com.annimon.stream.test.hamcrest.DoubleStreamMatcher;
 import com.annimon.stream.test.hamcrest.OptionalMatcher;
+import com.annimon.stream.test.hamcrest.StreamMatcher;
 import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -91,6 +92,12 @@ public void testStreamOfMapNull() {
         Stream.of((Map<?, ?>)null);
     }
 
+    @Test
+    public void testStreamOfEmptyArray() {
+        Stream.of(new String[0])
+                .custom(StreamMatcher.<String>assertIsEmpty());
+    }
+
     @Test
     public void testStreamOfIterator() {
         final PrintConsumer<Integer> consumer = new PrintConsumer<Integer>();