class OEmbedFieldWidgetTest

class OEmbedFieldWidgetTest extends MediaFunctionalTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * Tests that the oEmbed field widget shows the configured help text.
     */
    public function testFieldWidgetHelpText() : void {
        $account = $this->drupalCreateUser([
            'create media',
        ]);
        $this->drupalLogin($account);
        $media_type = $this->createMediaType('oembed:video');
        $source_field = $media_type->getSource()
            ->getSourceFieldDefinition($media_type)
            ->getName();
        
        /** @var \Drupal\field\Entity\FieldConfig $field */
        $field = FieldConfig::loadByName('media', $media_type->id(), $source_field);
        $field->setDescription('This is help text for oEmbed field.')
            ->save();
        $this->drupalGet('media/add/' . $media_type->id());
        $assert_session = $this->assertSession();
        $assert_session->pageTextContains('This is help text for oEmbed field.');
        $assert_session->pageTextContains('You can link to media from the following services: YouTube, Vimeo');
    }

}