Add and configure ESLint to GitLab test runner.

I have fixed the eslint comment for the gulpfile.js file. However, I encountered the problem "Unable to resolve path to module" in the Drupal core, which was solved with the help of the file's eslintignor. I have checked Gulp after the changes works well, but to eliminate comments, I follow the example of the kernel and include this file in the ignore.

I've fixed all eslint issues. Please check it

I have reviewed the changes and tested them in my Drupal 10 DDEV environment. They appear to be okay, and the last GitLab CI run did not flag any new ESLint errors or warnings.
Moving to RTBC.

Why edit the gulpfile then ignore it?

I have installed eslint and required plugins in the theme, added core config, updated all libraries and rebuilt the theme.

Runner didn't like me using the core config: https://git.drupalcode.org/project/collapsiblock/-/jobs/1060423

I've removed eslint for now, the changes made to source files should be enough, I hope.

Ok that has properly broken it.

We might need to redefine the eslint job for this module.

Going to concentrate on 📌 Add gitlab CI Needs work now and leave this open to ADD eslint job later.

Perhaps a good place to start would be on some of the larger contrib modules like webform to see if they have solved this.

So much happened since this was opened and I moved some of the work from here to the CI ticket so I've opened a fresh branch directly from 4.x so please use MR 25 going forward. I'm going to check if any of the remaining work here can be moved in to that.

I've resorted to ignoring the module import lines since it's core that's running eslint and it's not picking up our packages.

Tests are all passing but I would like a manual test to make triple sure this is still functioning correctly since I completely replaced the compiler.

Passes manual testing and everything is green except phpstan (next major) which has a separate issue open.

Thanks very much for your work on this everyone!

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