Add IsEmpty aggregation

Author: marcgeurts

docs/roadmap.md

@@ -71,7 +71,7 @@
 | slice                  | ✘ | ✘ | |
 | nth                    | ✘ | ✘ | |
 | offsetsOf              | ✘ | ✘ | |
-| isEmpty                | ✘ | ✘ | |
+| isEmpty                | ✘ | ✓ | |
 | union                  | ✘ | ✘ | |
 | sample                 | ✘ | ✘ | |
 | | | | |
@@ -80,7 +80,7 @@
 | ungroup                | ✘ | ✘ | |
 | reduce                 | ✘ | ✘ | |
 | fold                   | ✘ | ✘ | |
-| count                  | ✘ | ✘ | |
+| count                  | ✓ | ✓ | |
 | sum                    | ✘ | ✘ | |
 | avg                    | ✘ | ✘ | |
 | min                    | ✘ | ✘ | |

src/Query/Aggregation/AbstractAggregation.php

@@ -4,9 +4,18 @@
 namespace TBolier\RethinkQL\Query\Aggregation;
 
 use TBolier\RethinkQL\Query\AbstractQuery;
+use TBolier\RethinkQL\Query\QueryInterface;
 
 abstract class AbstractAggregation extends AbstractQuery implements AggregationInterface
 {
+    /**
+     * @inheritdoc
+     */
+    public function isEmpty(): QueryInterface
+    {
+        return new IsEmpty($this->rethink, $this->message, $this);
+    }
+
     /**
      * @inheritdoc
      */

src/Query/Aggregation/AggregationInterface.php

@@ -8,6 +8,11 @@
 
 interface AggregationInterface
 {
+    /**
+     * @return QueryInterface
+     */
+    public function isEmpty(): QueryInterface;
+
     /**
      * @param int $n
      * @return AggregationInterface

src/Query/Aggregation/IsEmpty.php

@@ -0,0 +1,45 @@
+<?php
+declare(strict_types = 1);
+
+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;
+
+class IsEmpty extends AbstractQuery
+{
+    /**
+     * @var QueryInterface
+     */
+    private $query;
+
+    /**
+     * @param RethinkInterface $rethink
+     * @param MessageInterface $message
+     * @param QueryInterface $query
+     */
+    public function __construct(RethinkInterface $rethink, MessageInterface $message, QueryInterface $query)
+    {
+        parent::__construct($rethink, $message);
+
+        $this->query = $query;
+        $this->rethink = $rethink;
+        $this->message = $message;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function toArray(): array
+    {
+        return [
+            TermType::IS_EMPTY,
+            [
+                $this->query->toArray(),
+            ],
+        ];
+    }
+}

test/integration/Aggregation/IsEmptyTest.php

@@ -0,0 +1,37 @@
+<?php
+declare(strict_types = 1);
+
+namespace TBolier\RethinkQL\IntegrationTest\Aggregation;
+
+use TBolier\RethinkQL\IntegrationTest\Query\AbstractTableTest;
+
+class IsEmptyTest extends AbstractTableTest
+{
+    /**
+     * @throws \Exception
+     */
+    public function testIsEmpty()
+    {
+        $res = $this->r()
+                    ->table('tabletest')
+                    ->isEmpty()
+                    ->run();
+
+        $this->assertTrue($res->getData());
+    }
+
+    /**
+     * @throws \Exception
+     */
+    public function testIsNotEmpty()
+    {
+        $this->insertDocument(1);
+
+        $res = $this->r()
+                    ->table('tabletest')
+                    ->isEmpty()
+                    ->run();
+
+        $this->assertFalse($res->getData());
+    }
+}

test/integration/Query/CountTest.php

@@ -3,7 +3,6 @@
 
 namespace TBolier\RethinkQL\IntegrationTest\Query;
 
-use TBolier\RethinkQL\IntegrationTest\Query\AbstractTableTest;
 use TBolier\RethinkQL\Response\ResponseInterface;
 
 class CountTest extends AbstractTableTest