CKEditor5 - character count stops when the text format is changed

The issue is in Full HTML of ckeditor-5.

Thanks for reporting this issue acemichael,

I can reproduce this issue as well.

A workaround is to save the form, edit it again and the MaxLength functionality begins working again.

I'm going to update this to be a 3.x-dev issue since that is the new version we will be actively maintaining.

I put in an MR for a change that worked for me:
Testing steps:
1. Installed Drupal core with standard profile (10.3.x)
2. Installed MaxLength 3.0.0-beta1
3. Configured article content type's body field widget to have a maxlength
4. Created a new article node
5. Typed some text into body field (format initially Basic HTML) and confirmed counter matches typing
6. Switched formats to Full HTML and confirmed via dialog
7. Resumed typing and confirmed counter still matches characters typed.

The fix is slightly ugly with the use of the MutationObserver. I think it can be cleaned up once ✨ Trigger event when Text Editor is attached Needs work in Drupal core is in, and there's event that can be listened for instead.

Going to put in needs review for feedback, though it probably needs tests.

Thank you for the contribution! Would be nice to see a test for this without the solution to validate the issue and in a new commit adding the fix should make the test pass.

Added test.

Failing test-only commit job: https://git.drupalcode.org/issue/maxlength-3391779/-/jobs/1182561
Fixed job: https://git.drupalcode.org/issue/maxlength-3391779/-/jobs/1182625

Fix looks good.

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