Add option to send email to multiple adresses

I'll be tackling this one!

Works and is ready for review!

Well done! I left the required comments. For examples of such update hooks, see our other projects. I think photoswipe has such.

Everything resolved, back to review!

Just one comment left. Now it needs three tests:
- No email address
- Single email address
- Multiple email addresses (one with space perhaps)?

We could also add a test for edge-cases, like a trailing or preceding comma or a wrongly formattet email address. That's something we would then need to check in hook_validate in the settings form, so it will not be stored and expects a form error.

I think that makes sense. Sth. like this:

  $email = $form_state->getValue('email_field');
  if (!\Drupal::service('email.validator')->isValid($email)) {
    $form_state->setErrorByName('email_field', t('Please enter a valid email address.'));
  }

(The service should probably be injected by dependency injection into the form class)

For further tests I added some ressources / links:
📌 Add basic test coverage Needs work

✨ Add multiple emails for email report. Active look like a duplicate?

We should combine both for the best solution. @LRWebks why didn't you mention this? You linked the issue :D

Currently, I am unsure of how to test this, as generating a PHP error manually to receive the email causes PHPUnit to stop the test... Should we "Postpone" / "Needs Review" and outsource the test to 📌 Add basic test coverage Needs work / keep this issue as is?

Yes, please make it part of the other issue. Indeed we need to take a closer look how to test this. I think there will be ways...

@LRWebks: Looking pretty good, well done!! :)

I left some comments. Regarding the tests: If they don't work, better move that code into the other issue.
It's fine if the tests there fail for now, but they should never exepect a wrong issue.

LGTM. Did you test this manually good enough? Also the update hook for existing installations?

Works fine, thank you!

Merged!

Needs test.

@nevergone: Just FYI: Typically Fixed / merged tasks should not be reopened, instead a follow-up should be created. In this case I'd just suggest to track all the tests we need in the testing issue.

But of course you decide!

@Anybody: Only tests added.

Automatically closed - issue fixed for 2 weeks with no activity.