Add Message test

tests/Unit/MessageTest.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * This file is part of Simps
+ *
+ * @link     https://github.com/simps/mqtt
+ * @contact  Lu Fei <[email protected]>
+ *
+ * For the full copyright and license information,
+ * please view the LICENSE file that was distributed with this source code
+ */
+
+declare(strict_types=1);
+
+namespace SimpsTest\MQTT\Unit;
+
+use PHPUnit\Framework\TestCase;
+use Simps\MQTT\Message;
+use Simps\MQTT\Protocol\ProtocolInterface;
+use Simps\MQTT\Protocol\Types;
+
+/**
+ * @internal
+ * @coversNothing
+ */
+class MessageTest extends TestCase
+{
+    public function testPublishMessage()
+    {
+        $message = new Message\Publish();
+        $message->setProtocolLevel(ProtocolInterface::MQTT_PROTOCOL_LEVEL_5_0)
+            ->setTopic('simps/mqtt/message')
+            ->setQos(ProtocolInterface::MQTT_QOS_1)
+            ->setDup(1)
+            ->setRetain(0)
+            ->setMessage('this is content')
+            ->setMessageId(1)
+            ->setProperties(['message_expiry_interval' => 100]);
+        $this->assertEquals(
+            $message->getContents(),
+            (string) $message,
+            'The results of getContents and toString should be the same'
+        );
+        $this->assertIsArray($message->getContents(true));
+    }
+
+    public function testPingRespMessage()
+    {
+        $message = new Message\PingResp();
+        $this->assertEquals(
+            $message->getContents(),
+            (string) $message,
+            'The results of getContents and toString should be the same'
+        );
+        $this->assertIsArray($message->getContents(true));
+        $this->assertEquals($message->getContents(true)['type'], Types::PINGRESP);
+    }
+}