Support ZADD modifiers when using simplified command signature.

The NX|XX, CH and INCR modifiers for ZADD are available in Redis since
version 3.0.2. See http://redis.io/commands/ZADD for additional info.

src/Command/ZSetAdd.php

@@ -30,15 +30,11 @@ class ZSetAdd extends Command
      */
     protected function filterArguments(array $arguments)
     {
-        if (count($arguments) === 2 && is_array($arguments[1])) {
-            $flattened = array($arguments[0]);
-
-            foreach ($arguments[1] as $member => $score) {
-                $flattened[] = $score;
-                $flattened[] = $member;
+        if (is_array(end($arguments))) {
+            foreach (array_pop($arguments) as $member => $score) {
+                $arguments[] = $score;
+                $arguments[] = $member;
             }
-
-            return $flattened;
         }
 
         return $arguments;

tests/Predis/Command/ZSetAddTest.php

@@ -61,6 +61,20 @@ class ZSetAddTest extends PredisCommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testFilterArgumentsMembersScoresAsSingleArrayWithModifiers()
+    {
+        $arguments = array('key', 'NX', 'CH', array('member1' => 1, 'member2' => 2));
+        $expected = array('key', 'NX', 'CH', 1, 'member1', 2, 'member2');
+
+        $command = $this->getCommand();
+        $command->setArguments($arguments);
+
+        $this->assertSame($expected, $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
@@ -83,6 +97,81 @@ class ZSetAddTest extends PredisCommandTestCase
         $this->assertSame(array('a', 'e', 'b', 'd', 'f', 'c'), $redis->zrange('letters', 0, -1));
     }
 
+    /**
+     * @group connected
+     * @requiresRedisVersion >= 3.0.2
+     */
+    public function testOnlyAddsNonExistingMembersWithModifierNX()
+    {
+        $redis = $this->getClient();
+
+        $this->assertSame(5, $redis->zadd('letters', 1, 'a', 2, 'b', 3, 'c', 4, 'd', 5, 'e'));
+        $this->assertSame(array('a', 'b', 'c', 'd', 'e'), $redis->zrange('letters', 0, -1));
+
+        $this->assertSame(2, $redis->zadd('letters', 'NX', 8, 'a', 1, 'f', 8, 'g', 4, 'e'));
+        $this->assertSame(array('a', 'f', 'b', 'c', 'd', 'e', 'g'), $redis->zrange('letters', 0, -1));
+    }
+
+    /**
+     * @group connected
+     * @requiresRedisVersion >= 3.0.2
+     */
+    public function testOnlyUpdatesExistingMembersWithModifierXX()
+    {
+        $redis = $this->getClient();
+
+        $this->assertSame(5, $redis->zadd('letters', 1, 'a', 2, 'b', 3, 'c', 4, 'd', 5, 'e'));
+        $this->assertSame(array('a', 'b', 'c', 'd', 'e'), $redis->zrange('letters', 0, -1));
+
+        $this->assertSame(0, $redis->zadd('letters', 'XX', 1, 'd', 2, 'c', 3, 'b', 1, 'x', 0, 'y'));
+        $this->assertSame(array('a', 'd', 'c', 'b', 'e'), $redis->zrange('letters', 0, -1));
+    }
+
+    /**
+     * @group connected
+     * @requiresRedisVersion >= 3.0.2
+     */
+    public function testReturnsNumberOfAddedAndUpdatedElementsWithModifierCH()
+    {
+        $redis = $this->getClient();
+
+        $this->assertSame(5, $redis->zadd('letters', 'CH', 1, 'a', 2, 'b', 3, 'c', 4, 'd', 5, 'e'));
+        $this->assertSame(array('a', 'b', 'c', 'd', 'e'), $redis->zrange('letters', 0, -1));
+
+        $this->assertSame(2, $redis->zadd('letters', 'NX', 'CH', 8, 'a', 1, 'f', 8, 'g', 4, 'e'));
+        $this->assertSame(array('a', 'f', 'b', 'c', 'd', 'e', 'g'), $redis->zrange('letters', 0, -1));
+
+        $this->assertSame(3, $redis->zadd('letters', 'XX', 'CH', 1, 'd', 2, 'c', 3, 'b', 1, 'x', 0, 'y'));
+        $this->assertSame(array('a', 'd', 'f', 'c', 'b', 'e', 'g'), $redis->zrange('letters', 0, -1));
+    }
+
+    /**
+     * @group connected
+     * @requiresRedisVersion >= 3.0.2
+     */
+    public function testActsLikeZINCRBYWithModifierINCR()
+    {
+        $redis = $this->getClient();
+
+        $this->assertSame('1', $redis->zadd('letters', 'INCR', 1, 'a'));
+        $this->assertSame('0', $redis->zadd('letters', 'INCR', -1, 'a'));
+        $this->assertSame('0.5', $redis->zadd('letters', 'INCR', 0.5, 'a'));
+        $this->assertSame('-10', $redis->zadd('letters', 'INCR', -10.5, 'a'));
+    }
+
+    /**
+     * @group connected
+     * @requiresRedisVersion >= 3.0.2
+     * @expectedException \Predis\Response\ServerException
+     * @expectedExceptionMessage INCR option supports a single increment-element pair
+     */
+    public function testDoesNotAcceptMultipleScoreElementPairsWithModifierINCR()
+    {
+        $redis = $this->getClient();
+
+        $redis->zadd('letters', 'INCR', 1, 'a', 2, 'b');
+    }
+
     /**
      * @group connected
      */