Add GROUP BY support to fetch

src/Query/GroupBy.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WyriHaximus\React\SimpleORM\Query;
+
+final class GroupBy implements SectionInterface
+{
+    /** @var array<string> */
+    private array $columns = [];
+
+    public function __construct(string ...$columns)
+    {
+        $this->columns = $columns;
+    }
+
+    /**
+     * @return iterable<string>
+     */
+    public function columns(): iterable
+    {
+        yield from $this->columns;
+    }
+}

src/Repository.php

@@ -17,6 +17,7 @@
 use Rx\Scheduler\ImmediateScheduler;
 use Safe\DateTimeImmutable;
 use WyriHaximus\React\SimpleORM\Annotation\JoinInterface;
+use WyriHaximus\React\SimpleORM\Query\GroupBy;
 use WyriHaximus\React\SimpleORM\Query\Limit;
 use WyriHaximus\React\SimpleORM\Query\Order;
 use WyriHaximus\React\SimpleORM\Query\SectionInterface;
@@ -25,6 +26,7 @@
 use WyriHaximus\React\SimpleORM\Query\Where\Field;
 
 use function array_key_exists;
+use function array_map;
 use function array_values;
 use function explode;
 use function is_scalar;
@@ -37,6 +39,7 @@
 use function Safe\substr;
 use function spl_object_hash;
 use function strpos;
+use function WyriHaximus\iteratorOrArrayToArray;
 
 use const WyriHaximus\Constants\Boolean\TRUE_;
 use const WyriHaximus\Constants\Numeric\ONE;
@@ -184,6 +187,16 @@ private function buildSelectQuery(SectionInterface ...$sections): SelectQuery
                         $query = $query->orderBy($field, $by->order());
                     }
 
+                    break;
+                case $section instanceof GroupBy:
+                    /**
+                     * @psalm-suppress ArgumentTypeCoercion
+                     * @psalm-suppress UndefinedInterfaceMethod
+                     */
+                    $query = $query->groupBy(array_map(
+                        fn (string $column): string => $this->translateFieldName($column),
+                        iteratorOrArrayToArray($section->columns())
+                    ));
                     break;
             }
         }

tests/FunctionalTest.php

@@ -14,6 +14,7 @@
 use WyriHaximus\React\SimpleORM\Client;
 use WyriHaximus\React\SimpleORM\ClientInterface;
 use WyriHaximus\React\SimpleORM\Middleware\QueryCountMiddleware;
+use WyriHaximus\React\SimpleORM\Query\GroupBy;
 use WyriHaximus\React\SimpleORM\Query\Limit;
 use WyriHaximus\React\SimpleORM\Query\Where;
 use WyriHaximus\React\Tests\SimpleORM\Stub\BlogPostStub;
@@ -584,4 +585,15 @@ public function countWithConstraints(): void
         $count = $this->await($repository->count(new Where(new Where\Field('author_id', 'eq', ['fb175cbc-04cc-41c7-8e35-6b817ac016ca']))), $this->loop, self::AWAIT_TIMEOUT);
         self::assertSame(1, $count);
     }
+
+    /**
+     * @test
+     */
+    public function groupBy(): void
+    {
+        $repository = $this->client->repository(BlogPostStub::class);
+
+        $count = $this->await($repository->fetch(new GroupBy('author_id'))->count()->toPromise(), $this->loop, self::AWAIT_TIMEOUT);
+        self::assertSame(1, $count);
+    }
 }