--- /dev/null
+<?php
+
+namespace Drupal\Tests\video_embed_field\FunctionalJavascript;
+
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+use Drupal\Tests\video_embed_field\Functional\EntityDisplaySetupTrait;
+
+/**
+ * Test the lazy load formatter.
+ *
+ * @group video_embed_field
+ */
+class LazyLoadFormatterTest extends JavascriptTestBase {
+
+ use EntityDisplaySetupTrait;
+
+ /**
+ * {@inheritdoc}
+ */
+ public static $modules = [
+ 'node',
+ 'video_embed_field',
+ 'video_embed_field_mock_provider',
+ ];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUp() {
+ parent::setUp();
+ $this->setupEntityDisplays();
+ }
+
+ /**
+ * Test the lazy load formatter.
+ */
+ public function testColorboxFormatter() {
+ $this->setDisplayComponentSettings('video_embed_field_lazyload', [
+ 'autoplay' => TRUE,
+ 'responsive' => TRUE,
+ ]);
+ $node = $this->createVideoNode('https://example.com/mock_video');
+ $this->drupalGet('node/' . $node->id());
+ $this->click('.video-embed-field-lazy');
+ $this->assertSession()->elementExists('css', '.video-embed-field-lazy .video-embed-field-responsive-video');
+ // Make sure the right library files are loaded on the page.
+ $this->assertSession()->elementContains('css', 'style', 'video_embed_field/css/video_embed_field.responsive-video.css');
+ }
+
+}