Issue #3192059 by chr.fritsch, Abhijith S, phenaproxima, alexpott: Use the...

  /**

   * Determines if the source field value has changed.

   *

   * The comparison uses MediaSourceInterface::getSourceFieldValue() to ensure

   * that the correct property from the source field is used.

   *

   * @return bool

   *   TRUE if the source field value changed, FALSE otherwise.

   *

   * @see \Drupal\media\MediaSourceInterface::getSourceFieldValue()

   *

   * @internal

   */

  protected function hasSourceFieldChanged() {

    $source_field_name = $this->getSource()->getConfiguration()['source_field'];

    $current_items = $this->get($source_field_name);

    return isset($this->original) && !$current_items->equals($this->original->get($source_field_name));

    $source = $this->getSource();

    return isset($this->original) && $source->getSourceFieldValue($this) !== $source->getSourceFieldValue($this->original);

  }

  /**

<?php

namespace Drupal\Tests\media\Functional;

use Drupal\field\Entity\FieldConfig;

use Drupal\file\Entity\File;

use Drupal\media\Entity\Media;

use Drupal\Tests\TestFileCreationTrait;

/**

 * Tests the image media source.

 *

 * @group media

 */

class MediaSourceImageTest extends MediaFunctionalTestBase {

  use TestFileCreationTrait;

  /**

   * {@inheritdoc}

   */

  protected $defaultTheme = 'stark';

  /**

   * Test that non-main properties do not trigger source field value change.

   */

  public function testOnlyMainPropertiesTriggerSourceFieldChanged() {

    $assert_session = $this->assertSession();

    $page = $this->getSession()->getPage();

    $media_type = $this->createMediaType('image');

    $media_type_id = $media_type->id();

    $media_type->setFieldMap(['name' => 'name']);

    $media_type->save();

    /** @var \Drupal\field\FieldConfigInterface $field */

    // Disable the alt text field, because this is not a JavaScript test and

    // the alt text field will therefore not appear without a full page refresh.

    $field = FieldConfig::load("media.$media_type_id.field_media_image");

    $settings = $field->getSettings();

    $settings['alt_field'] = TRUE;

    $settings['alt_field_required'] = FALSE;

    $field->set('settings', $settings);

    $field->save();

    $file = File::create([

      'uri' => $this->getTestFiles('image')[0]->uri,

    ]);

    $file->save();

    $media = Media::create([

      'name' => 'Custom name',

      'bundle' => $media_type_id,

      'field_media_image' => $file->id(),

    ]);

    $media->save();

    // Change only the alt of the image.

    $this->drupalGet($media->toUrl('edit-form'));

    $this->submitForm(['field_media_image[0][alt]' => 'Alt text'], 'Save');

    // Custom name should stay.

    $this->drupalGet($media->toUrl('edit-form'));

    $assert_session->fieldValueEquals('name[0][value]', 'Custom name');

    // Remove image and attach a new one.

    $this->submitForm([], 'Remove');

    $image_media_name = 'example_1.jpeg';

    $page->attachFileToField('files[field_media_image_0]', $this->root . '/core/modules/media/tests/fixtures/' . $image_media_name);

    $page->pressButton('Save');

    $this->drupalGet($media->toUrl('edit-form'));

    $assert_session->fieldValueEquals('name[0][value]', 'example_1.jpeg');

  }

}