Fix \Drupal\Tests\media\Kernel\MediaSourceTest on PHP 8.5

Before the fix, executing the test resulted in four deprecations:

laptop:~/drupal_core$ phpunit core/modules/media/tests/src/Kernel/MediaSourceTest.php
PHPUnit 11.5.42 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.5.0RC3
Configuration: /var/www/html/phpunit.xml

........DD                                                        10 / 10 (100%)

Time: 00:11.784, Memory: 6.00 MB

2 tests triggered 4 PHP deprecations:

1) /var/www/html/core/lib/Drupal/Core/Entity/EntityFieldManager.php:356
Using null as an array offset is deprecated, use an empty string instead

Triggered by:

* Drupal\Tests\media\Kernel\MediaSourceTest::testDifferentSourceFieldDisplays
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:616

* Drupal\Tests\media\Kernel\MediaSourceTest::testHiddenSourceField
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:637

2) /var/www/html/core/modules/field/src/Hook/FieldHooks.php:229
Using null as an array offset is deprecated, use an empty string instead

Triggered by:

* Drupal\Tests\media\Kernel\MediaSourceTest::testDifferentSourceFieldDisplays
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:616

* Drupal\Tests\media\Kernel\MediaSourceTest::testHiddenSourceField
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:637

3) /var/www/html/core/lib/Drupal/Core/Entity/EntityFieldManager.php:372
Using null as an array offset is deprecated, use an empty string instead

Triggered by:

* Drupal\Tests\media\Kernel\MediaSourceTest::testDifferentSourceFieldDisplays
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:616

* Drupal\Tests\media\Kernel\MediaSourceTest::testHiddenSourceField
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:637

4) /var/www/html/core/lib/Drupal/Core/Entity/EntityFieldManager.php:374
Using null as an array offset is deprecated, use an empty string instead

Triggered by:

* Drupal\Tests\media\Kernel\MediaSourceTest::testDifferentSourceFieldDisplays
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:616

* Drupal\Tests\media\Kernel\MediaSourceTest::testHiddenSourceField
  /var/www/html/core/modules/media/tests/src/Kernel/MediaSourceTest.php:637

Afterward there were no deprecations. I double-checked the deprecation backtraces and verified that they're all due to missing bundle IDs. I really wish we could add parameter type hints to EntityFieldManager::getFieldDefinitions(). /sigh

But this needs a code style change to avoid conflicting with Drupal.Array.Array.LongLineDeclaration which is in an RTBC MR.

Hi, I’m new to Drupal contribution. I can’t see the Join group or Assign to me option yet. Could someone please add me to the Drupal core contributors group? My username is r_mahi.

@r_mahi please read https://www.drupal.org/community/contributor-guide/contribution-areas/core. In particular there is a link to the Drupal #contribute Slack channel. I encourage you to seek assistance there for getting started. Right now Drupal is in the middle of transitioning from its custom issue queue to GitLab. This comes with particular challenges when learning how and where to do things. Putting that information into an issue comment isn't appropriate. It would be best if you could use Slack to communicate directly with other contributors for assistance.

Updated my ddev to 8.5.0RC3 and ran testDifferentSourceFieldDisplays which has createMediaTypeViaForm() and got
1 test triggered 4 PHP deprecations:

Applied the MR.

Re-ran same exact test and got 0 deprecations.

LGTM

Committed/pushed to 11.x and cherry-picked to 11.3.x, thanks!