Overwrite-methods that take Bytes as parameters. Tests for IndexOutOf… (#35)

* Overwrite-methods that take Bytes as parameters. Tests for IndexOutOfBounds-exception when overwritten array exceeds the original size and NullPointerException when the array used to overwrite is null

* add requested changes

Author: JadePaukkunen

CHANGELOG

@@ -1,5 +1,10 @@
 # Releases
 
+## Unreleased
+
+* adds overwrite method to Bytes
+* adds tests to NullPointerException and IndexOutOfBoundsException
+
 ## v1.1.0
 
 * add `unsecureRandom()` constructor which creates random for e.g. tests or deterministic randoms

src/main/java/at/favre/lib/bytes/MutableBytes.java

@@ -71,10 +71,25 @@ public boolean isMutable() {
      * @return this instance
      * @throws IndexOutOfBoundsException if newArray.length > internal length
      */
+
     public MutableBytes overwrite(byte[] newArray) {
+
         return overwrite(newArray, 0);
     }
 
+    /**
+     * Uses given Bytes array to overwrite internal array
+     *
+     * @param newBytes used to overwrite internal
+     * @return this instance
+     * @throws IndexOutOfBoundsException if newArray.length > internal length
+     */
+
+    public MutableBytes overwrite(Bytes newBytes) {
+
+        return overwrite(newBytes, 0);
+    }
+
     /**
      * Uses given array to overwrite internal array.
      *
@@ -83,12 +98,26 @@ public MutableBytes overwrite(byte[] newArray) {
      * @return this instance
      * @throws IndexOutOfBoundsException if newArray.length + offsetInternalArray > internal length
      */
+
     public MutableBytes overwrite(byte[] newArray, int offsetInternalArray) {
         Objects.requireNonNull(newArray, "must provide non-null array as source");
         System.arraycopy(newArray, 0, internalArray(), offsetInternalArray, newArray.length);
         return this;
     }
 
+    /**
+     * Uses given Bytes array to overwrite internal array.
+     *
+     * @param newBytes            used to overwrite internal
+     * @param offsetInternalArray index of the internal array to start overwriting
+     * @return this instance
+     * @throws IndexOutOfBoundsException if newBytes.length + offsetInternalArray > internal length
+     */
+
+    public MutableBytes overwrite(Bytes newBytes, int offsetInternalArray) {
+        return overwrite(Objects.requireNonNull(newBytes, "must provide non-null array as source").array(), offsetInternalArray);
+    }
+
     /**
      * Sets new byte to given index
      *

src/test/java/at/favre/lib/bytes/MutableBytesTest.java

@@ -63,6 +63,50 @@ public void overwritePartialArray2() {
                         .append(Bytes.wrap(example_bytes_seven).copy(2, example_bytes_seven.length - 2)).array(), b.array());
     }
 
+    @Test
+    public void overwriteBytes() {
+        MutableBytes a = fromAndTest(example_bytes_seven).mutable();
+        MutableBytes b = Bytes.from((byte)0).mutable();
+        MutableBytes c = a.overwrite(b, 0).mutable();
+        MutableBytes d = Bytes.wrap(a).copy(1, a.array().length-1).mutable();
+
+        assertArrayEquals(c.array(), Bytes.from(b).append(d).array());
+    }
+
+    @Test
+    public void overwriteTooBigArrayShouldThrowException() {
+        MutableBytes b = fromAndTest(example_bytes_seven).mutable();
+        try {
+            b.overwrite(new byte[]{(byte) 0xAA, 0x30}, b.length());
+            fail();
+        } catch(IndexOutOfBoundsException ignored) {}
+
+    }
+
+    @Test
+    public void overwriteTooBigBytesShouldThrowException() {
+        MutableBytes b = fromAndTest(example_bytes_seven).mutable();
+        try {
+            b.overwrite(Bytes.from((byte) 0xAA, 0x30), b.length());
+            fail();
+        } catch(IndexOutOfBoundsException ignored) {}
+
+    }
+
+    @Test
+    public void overwriteNullArrayShouldThrowException() {
+        MutableBytes nonsense = null;
+        MutableBytes b = fromAndTest(example_bytes_seven).mutable();
+
+        try{
+            b.overwrite(nonsense);
+            fail();
+        } catch (NullPointerException ignored){}
+
+
+    }
+
+
     @Test
     public void fill() {
         MutableBytes b = fromAndTest(example_bytes_seven).mutable();
@@ -184,4 +228,5 @@ public void testAutoCloseable() {
         assertArrayNotEquals(new byte[16], leak.array());
 
     }
+
 }