Add skip aggregation

Author: marcgeurts

docs/roadmap.md

@@ -66,7 +66,7 @@
 | withFields             | ✘ | ✘ | |
 | concatMap              | ✘ | ✘ | |
 | orderBy                | ✘ | ✓ | |
-| skip                   | ✘ | ✘ | |
+| skip                   | ✘ | ✓ | |
 | limit                  | ✘ | ✓ | |
 | slice                  | ✘ | ✘ | |
 | nth                    | ✘ | ✘ | |

src/Query/Aggregation/AbstractAggregation.php

@@ -15,6 +15,14 @@ public function limit($value): AggregationInterface
         return new Limit($this->rethink, $this->message, $this, $value);
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function skip($value): AggregationInterface
+    {
+        return new Skip($this->rethink, $this->message, $this, $value);
+    }
+
     /**
      * @inheritdoc
      */

src/Query/Aggregation/AggregationInterface.php

@@ -14,6 +14,12 @@ interface AggregationInterface
      */
     public function limit($n): AggregationInterface;
 
+    /**
+     * @param int $n
+     * @return AggregationInterface
+     */
+    public function skip($n): AggregationInterface;
+
     /**
      * @param mixed|QueryInterface $key
      * @return AggregationInterface

src/Query/Aggregation/Limit.php

@@ -4,7 +4,6 @@
 namespace TBolier\RethinkQL\Query\Aggregation;
 
 use TBolier\RethinkQL\Message\MessageInterface;
-use TBolier\RethinkQL\Query\AbstractQuery;
 use TBolier\RethinkQL\Query\QueryInterface;
 use TBolier\RethinkQL\RethinkInterface;
 use TBolier\RethinkQL\Types\Term\TermType;

src/Query/Aggregation/Skip.php

@@ -0,0 +1,59 @@
+<?php
+declare(strict_types = 1);
+
+namespace TBolier\RethinkQL\Query\Aggregation;
+
+use TBolier\RethinkQL\Message\MessageInterface;
+use TBolier\RethinkQL\Query\QueryInterface;
+use TBolier\RethinkQL\RethinkInterface;
+use TBolier\RethinkQL\Types\Term\TermType;
+
+class Skip extends AbstractAggregation
+{
+    /**
+     * @var int
+     */
+    private $n;
+
+    /**
+     * @var QueryInterface
+     */
+    private $query;
+
+    /**
+     * @param RethinkInterface $rethink
+     * @param MessageInterface $message
+     * @param QueryInterface $query
+     * @param $n
+     */
+    public function __construct(
+        RethinkInterface $rethink,
+        MessageInterface $message,
+        QueryInterface $query,
+        int $n
+    ) {
+        parent::__construct($rethink, $message);
+
+        $this->query = $query;
+        $this->n = $n;
+        $this->rethink = $rethink;
+        $this->message = $message;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function toArray(): array
+    {
+        return [
+            TermType::SKIP,
+            [
+                $this->query->toArray(),
+                [
+                    TermType::DATUM,
+                    $this->n,
+                ],
+            ],
+        ];
+    }
+}

test/integration/Aggregation/SkipTest.php

@@ -0,0 +1,77 @@
+<?php
+declare(strict_types = 1);
+
+namespace TBolier\RethinkQL\IntegrationTest\Aggregation;
+
+use TBolier\RethinkQL\IntegrationTest\Query\AbstractTableTest;
+use TBolier\RethinkQL\Response\Cursor;
+use TBolier\RethinkQL\Response\ResponseInterface;
+
+class SkipTest extends AbstractTableTest
+{
+    /**
+     * @return void
+     * @throws \Exception
+     */
+    public function testSkip(): void
+    {
+        $this->insertDocument(1);
+        $this->insertDocument(2);
+        $this->insertDocument(3);
+        $this->insertDocument(4);
+        $this->insertDocument(5);
+
+        /** @var Cursor $cursor */
+        $cursor = $this->r()
+            ->table('tabletest')
+            ->skip(2)
+            ->run();
+
+        $this->assertCount(3, $cursor);
+    }
+
+    /**
+     * @return void
+     * @throws \Exception
+     */
+    public function testFilterAndSkip(): void
+    {
+        $this->insertDocument(1);
+        $this->insertDocument(2);
+        $this->insertDocument(3);
+        $this->insertDocument(4);
+        $this->insertDocument(5);
+
+        /** @var Cursor $cursor */
+        $cursor = $this->r()
+                       ->table('tabletest')
+                       ->filter(['description' => 'A document description.'])
+                       ->skip(2)
+                       ->run();
+
+        $this->assertCount(3, $cursor);
+    }
+
+    /**
+     * @return void
+     * @throws \Exception
+     */
+    public function testSkipAndOrderBy(): void
+    {
+        $this->insertDocument(1);
+        $this->insertDocument(2);
+        $this->insertDocument(3);
+        $this->insertDocument(4);
+        $this->insertDocument(5);
+
+        /** @var ResponseInterface $res */
+        $res = $this->r()
+                       ->table('tabletest')
+                       ->filter(['description' => 'A document description.'])
+                       ->skip(2)
+                       ->orderBy($this->r()->asc('id'))
+                       ->run();
+
+        $this->assertArraySubset(['id' => 1], $res->getData()[0]);
+    }
+}