test(phpunit): Better tests for streams

tests/YoutubeStreamTest.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * YoutubeStreamTest class.
+ */
+
+namespace Alltube\Test;
+
+use Alltube\Stream\YoutubeStream;
+use Alltube\Video;
+
+/**
+ * Unit tests for the YoutubeStream class.
+ */
+class YoutubeStreamTest extends StreamTest
+{
+    /**
+     * Prepare tests.
+     */
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $video = new Video('https://www.youtube.com/watch?v=dQw4w9WgXcQ', '135');
+
+        $this->stream = new YoutubeStream($video);
+    }
+}