fix event segment (#87)

src/OneBot/V12/Object/OneBotEvent.php

@@ -130,7 +130,7 @@ public function getMessage(bool $return_assoc_array = false): ?array
         }
         $this->message_segment_cache = [];
         foreach ($this->data['message'] as $segment) {
-            $this->message_segment_cache[] = new MessageSegment($segment['type'], $segment['data']);
+            $this->message_segment_cache[] = $segment instanceof MessageSegment ? $segment : new MessageSegment($segment['type'], $segment['data']);
         }
         return $this->message_segment_cache;
     }

tests/OneBot/V12/Object/OneBotEventTest.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\OneBot\V12\Object;
+
+use OneBot\V12\Object\MessageSegment;
+use OneBot\V12\Object\OneBotEvent;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @internal
+ */
+class OneBotEventTest extends TestCase
+{
+    public function testGetMessageSegments(): void
+    {
+        $event = new OneBotEvent([
+            'id' => '123',
+            'type' => 'message',
+            'self' => [
+                'user_id' => '123',
+                'platform' => 'test',
+            ],
+            'detail_type' => 'group',
+            'sub_type' => 'normal',
+            'time' => 123,
+            'alt_message' => '123',
+            'group_id' => '123',
+            'user_id' => '123',
+            'guild_id' => '123',
+            'channel_id' => '123',
+            'operator_id' => '123',
+            'message_id' => '123',
+            'message' => [
+                [
+                    'type' => 'text',
+                    'data' => [
+                        'text' => '123',
+                    ],
+                ],
+            ],
+        ]);
+        $event->setMessage([ob_segment('mention', ['user_id' => '123456'])]);
+        $this->assertInstanceOf(MessageSegment::class, $event->getMessage()[0]);
+    }
+}