Underscore.js library was deprecated in Drupal 9.4 (
https://www.drupal.org/node/3273118 →
)
But it is used in following files: attributes.js, drupal.bootstrap.js, modal.js
Drupal 10 has Underscore.js library in core yet so there is a quick fix for this: Issue #3343708 🐛 Underscore.js library is deprecated under Drupal 10, quick dependencies fix Fixed
But this library can be removed from core any moment so for long term there two possible solutions:
1) Get rid of Underscore.js usage at all (replacing with vanilla JS code probably).
2) Add copy of Underscore.js library to theme sources and use it as dependency to be sure that things will work even if Underscore.js library will be removed from Drupal core completely. It is safe to have Underscore.js library from both theme and Drupal core because it checks internally if it already loaded and will not load second time.
I'm not so good in JS so I can not do 1)
But if no one will do it I can prepare merge request for 2)
Waiting for maintainers opinions on this :)
Active
3.0
Code
Setting back to Active, as there is no patch or MR that Needs work. Our organization is happy to sponsor the development time for option 1
1) Get rid of Underscore.js usage at all (replacing with vanilla JS code probably).