From c0f45adc2ca696c0317edab2cf3eed89adaf17bc Mon Sep 17 00:00:00 2001
From: Herman Lyakhovich <53296879+hlyakhovich@users.noreply.github.com>
Date: Wed, 17 Mar 2021 19:29:22 +0100
Subject: [PATCH] Overload from() with short array

---
 src/main/java/at/favre/lib/bytes/Bytes.java   | 12 +++++++-
 src/main/java/at/favre/lib/bytes/Util.java    | 28 ++++++++++++++++++-
 .../lib/bytes/BytesConstructorTests.java      | 13 +++++++++
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/src/main/java/at/favre/lib/bytes/Bytes.java b/src/main/java/at/favre/lib/bytes/Bytes.java
index 42541e6..3797292 100644
--- a/src/main/java/at/favre/lib/bytes/Bytes.java
+++ b/src/main/java/at/favre/lib/bytes/Bytes.java
@@ -296,6 +296,16 @@ public static Bytes from(short short2Byte) {
         return wrap(ByteBuffer.allocate(2).putShort(short2Byte).array());
     }
 
+    /**
+     * Creates a new instance from given 2 byte short array.
+     *
+     * @param shortArray to create from
+     * @return new instance
+     */
+    public static Bytes from(short... shortArray) {
+        return wrap(Util.Converter.toByteArray(Objects.requireNonNull(shortArray, "must provide at least a single short")));
+    }
+
     /**
      * Creates a new instance from given 4 byte integer.
      *
@@ -1492,7 +1502,7 @@ public Bytes duplicate() {
     /**
      * Set the byte order or endianness of this instance. Default in Java is {@link ByteOrder#BIG_ENDIAN}.
      * <p>
-     * This option is important for all encoding and conversation methods.
+     * This option is important for all encoding and conversion methods.
      *
      * @param byteOrder new byteOrder
      * @return a new instance with the same underlying array and new order, or "this" if order is the same
diff --git a/src/main/java/at/favre/lib/bytes/Util.java b/src/main/java/at/favre/lib/bytes/Util.java
index da50ff0..710c4d3 100644
--- a/src/main/java/at/favre/lib/bytes/Util.java
+++ b/src/main/java/at/favre/lib/bytes/Util.java
@@ -567,6 +567,33 @@ static byte[] toPrimitiveArray(java.lang.Byte[] objectArray) {
             return primitivesArray;
         }
 
+        /**
+         * Creates a byte array from given short array.
+         * The resulting byte array will have length shortArray * 2.
+         *
+         * <p>
+         * <strong>Analysis</strong>
+         * <ul>
+         * <li>Time Complexity: <code>O(n)</code></li>
+         * <li>Space Complexity: <code>O(n)</code></li>
+         * <li>Alters Parameters: <code>false</code></li>
+         * </ul>
+         * </p>
+         *
+         * @param shortArray to convert
+         * @return resulting byte array
+         */
+        static byte[] toByteArray(short[] shortArray) {
+            byte[] primitivesArray = new byte[shortArray.length * 2];
+            ByteBuffer buffer = ByteBuffer.allocate(2);
+            for (int i = 0; i < shortArray.length; i++) {
+                buffer.clear();
+                byte[] shortBytes = buffer.putShort(shortArray[i]).array();
+                System.arraycopy(shortBytes, 0, primitivesArray, (i * 2), shortBytes.length);
+            }
+            return primitivesArray;
+        }
+
         /**
          * Creates a byte array from given int array.
          * The resulting byte array will have length intArray * 4.
@@ -860,7 +887,6 @@ static double[] toDoubleArray(byte[] bytes, ByteOrder byteOrder) {
             return array;
         }
 
-
         /**
          * Converts the byte array to a short array. This will spread 2 bytes into a single short:
          *
diff --git a/src/test/java/at/favre/lib/bytes/BytesConstructorTests.java b/src/test/java/at/favre/lib/bytes/BytesConstructorTests.java
index 612dba3..5cf5058 100644
--- a/src/test/java/at/favre/lib/bytes/BytesConstructorTests.java
+++ b/src/test/java/at/favre/lib/bytes/BytesConstructorTests.java
@@ -179,6 +179,19 @@ public void fromShort() {
         assertEquals(test, Bytes.from(test).toShort());
     }
 
+    @Test(expected = NullPointerException.class)
+    public void fromShortArray_empty_shouldThrow() {
+        Bytes.from((short[]) null);
+    }
+
+    @Test
+    public void fromShortArray() {
+        assertArrayEquals(new byte[]{0, 1, 0, 2}, Bytes.from((short) 1, (short) 2).array());
+        assertArrayEquals(Bytes.from(Bytes.from((short) 32767), Bytes.from((short) 6761), Bytes.from((short) -8517)).array(), Bytes.from((short) 32767, (short) 6761, (short) -8517).array());
+        assertArrayEquals(Bytes.from(Bytes.from((short) 1678), Bytes.from((short) -223), Bytes.from((short) 11114)).array(), Bytes.from((short) 1678, (short) -223, (short) 11114).array());
+        assertArrayEquals(new byte[]{114, -123, 35, 53, 0, 0, 56, -70}, Bytes.from((short) 29317, (short) 9013, (short) 0, (short) 14522).array());
+    }
+
     @Test
     public void fromInt() {
         int test = 722837193;