Add ConfigImporter to \Drupal\Core\Config\Importer\MissingContentEvent

I think we can thread it as a bug because the event is not really migrate event

@andypost what does Migrate have to do with it?

Sorry, I mean config import event

-class MissingContentEvent extends Event {
+class MissingContentEvent extends ConfigImporterEvent {

But it is a Config import event - is only triggered by the ConfigImporter - see the constructor...

  /**
   * Constructs a configuration import missing content event object.
   *
   * @param array $missing_content
   *   Missing content information.
   */
  public function __construct(array $missing_content) {
    $this->missingContent = $missing_content;
  }

Ran locally and got

Testing /var/www/html/web/core/tests/Drupal/KernelTests/Core/Config

Error : Call to undefined method Drupal\Core\Config\Importer\MissingContentEvent::getConfigImporter()

To show the test-coverage. Couldn't run the test-only feature here.

Test of code change appears fine though and didn't appear to break anything.

Was on the fence about backporting this as it adds a tiny bit of API but this seems unlikely to be unused outside of the ConfigImporter and if backporting allows us to unblock contrib then let's do that.

Committed and pushed eafa856443 to 11.x and 476e65a1e1 to 10.2.x. Thanks!

longwave → closed merge request !6202

Thank you a lot, it is great help for default content!

Hmm, we're using the MissingContentEvent in our unit tests for ECA and they're now failing. Should we add the config importer argument in our tests and ignore the warning about too many arguments in earlier core versions?

Whoops, I thought I searched contrib and found no uses, maybe an error on my part. Happy to revert and rework it if that solves the issue.

Not sure if it's worth it, don't want to hold back some otherwise unblocking improvements. We're "only" using this is a unit test, and could just add that second argument there. It shouldn't break anything for users, I suspect.

Looking at it again, decided to revert; let's add a default value for that new argument so existing callers don't break.