Extend Sorted Set support by implementing ZDIFFSTORE command

src/ClientContextInterface.php

@@ -110,6 +110,7 @@
  * @method $this zcard($key)
  * @method $this zcount($key, $min, $max)
  * @method $this zdiff(array $keys, bool $withScores = false)
+ * @method $this zdiffstore(string $destination, array $keys)
  * @method $this zincrby($key, $increment, $member)
  * @method $this zinterstore($destination, array|string $keys, array $options = null)
  * @method $this zmscore(string $key, string ...$member)

src/ClientInterface.php

@@ -126,6 +126,7 @@
  * @method int               zcard(string $key)
  * @method string            zcount(string $key, int|string $min, int|string $max)
  * @method array             zdiff(array $keys, bool $withScores = false)
+ * @method int               zdiffstore(string $destination, array $keys)
  * @method string            zincrby(string $key, int $increment, string $member)
  * @method int               zinterstore(string $destination, array|string $keys, array $options = null)
  * @method array             zmscore(string $key, string ...$member)

src/Command/Redis/ZDIFFSTORE.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Predis\Command\Redis;
+
+use Predis\Command\Command as RedisCommand;
+use Predis\Command\Traits\Numkeys;
+use Predis\Command\Traits\Keys;
+
+/**
+ * @link https://redis.io/commands/zdiffstore/
+ *
+ * Computes the difference between the first and all successive input sorted sets
+ * and stores the result in destination. The total number of input keys is specified by numkeys.
+ *
+ * Keys that do not exist are considered to be empty sets.
+ *
+ * If destination already exists, it is overwritten.
+ */
+class ZDIFFSTORE extends RedisCommand
+{
+    use Keys;
+    use Numkeys {
+        setArguments as setNumkeys;
+    }
+
+    public static $keysArgumentPositionOffset = 1;
+
+    public function getId()
+    {
+        return 'ZDIFFSTORE';
+    }
+
+    public function setArguments(array $arguments)
+    {
+        $this->setNumkeys($arguments);
+        $arguments = $this->getArguments();
+        $this->unpackKeysArray(self::$keysArgumentPositionOffset + 1, $arguments);
+        parent::setArguments($arguments);
+    }
+}

src/Command/Redis/ZMSCORE.php

@@ -12,7 +12,6 @@
  *
  * For every member that does not exist in the sorted set, a null value is returned.
  *
- * @version >= 6.2.0
  */
 class ZMSCORE extends RedisCommand
 {

src/Command/Redis/ZRANDMEMBER.php

@@ -15,7 +15,6 @@
  * If called with a negative count, the behavior changes and the command
  * is allowed to return the same element multiple times.
  *
- * @version >= 6.2.0
  */
 class ZRANDMEMBER extends RedisCommand
 {

tests/Predis/Command/Redis/ZDIFFSTORE_Test.php

@@ -0,0 +1,95 @@
+<?php
+
+namespace Predis\Command\Redis;
+
+class ZDIFFSTORE_Test extends PredisCommandTestCase
+{
+    /**
+     * @inheritDoc
+     */
+    protected function getExpectedCommand(): string
+    {
+        return ZDIFFSTORE::class;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    protected function getExpectedId(): string
+    {
+        return 'ZDIFFSTORE';
+    }
+
+    /**
+     * @group disconnected
+     */
+    public function testFilterArguments(): void
+    {
+        $actualArguments = ['zset_diff', ['key1', 'key2']];
+        $expectedArguments = ['zset_diff', 2, 'key1', 'key2'];
+
+        $command = $this->getCommand();
+        $command->setArguments($actualArguments);
+
+        $this->assertSame($expectedArguments, $command->getArguments());
+    }
+
+    /**
+     * @group disconnected
+     */
+    public function testParseResponse(): void
+    {
+        $this->assertSame(1, $this->getCommand()->parseResponse(1));
+    }
+
+    /**
+     * @group connected
+     * @dataProvider sortedSetsProvider
+     * @param array $firstSetDictionary
+     * @param array $secondSetDictionary
+     * @param array $expectedResponse
+     * @param int $expectedResultingElements
+     * @return void
+     * @requiresRedisVersion >= 6.2.0
+     */
+    public function testStoresDifferenceBetweenSortedSets(
+        array $firstSetDictionary,
+        array $secondSetDictionary,
+        array $expectedResponse,
+        int $expectedResultingElements
+    ): void {
+        $redis = $this->getClient();
+
+        $redis->zadd('test-zset-1', ...$firstSetDictionary);
+        $redis->zadd('test-zset-2', ...$secondSetDictionary);
+        $actualResponse = $redis->zdiffstore('zdiffstore', ['test-zset-1', 'test-zset-2']);
+
+        $this->assertSame($expectedResultingElements, $actualResponse);
+        $this->assertSame($expectedResponse, $redis->zrange('zdiffstore', 0, -1));
+    }
+
+
+    public function sortedSetsProvider(): array
+    {
+        return [
+            'no intersection' => [
+                [1, 'member1', 2, 'member2', 3, 'member3'],
+                [1, 'member4', 2, 'member5', 3, 'member6'],
+                ['member1', 'member2', 'member3'],
+                3
+            ],
+            'partial intersection' => [
+                [1, 'member1', 2, 'member2', 3, 'member3'],
+                [1, 'member1', 2, 'member2', 3, 'member4'],
+                ['member3'],
+                1
+            ],
+            'full intersection' => [
+                [1, 'member1', 2, 'member2', 3, 'member3'],
+                [1, 'member1', 2, 'member2', 3, 'member3'],
+                [],
+                0
+            ],
+        ];
+    }
+}