Add support for Rails 8

[n-rodriguez]

Hi there!

I've updated my app to Rails 8 and now got this error in CI :

     NoMethodError:
       undefined method `mobility_backend_class' for nil
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:192:in `backend_node'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:233:in `block (2 levels) in _build'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:232:in `map'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:232:in `block in _build'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:227:in `each'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:227:in `inject'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:227:in `_build'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:213:in `build'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:130:in `where!'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activerecord-8.0.0/lib/active_record/relation/query_methods.rb:1039:in `where'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/mobility-1.2.9/lib/mobility/plugins/active_record/query.rb:136:in `where'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/finder_methods.rb:54:in `exists_by_friendly_id?'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/slug_generator.rb:15:in `available?'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/slug_generator.rb:19:in `block in generate'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/candidates.rb:16:in `block in each'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/candidates.rb:16:in `each'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/candidates.rb:16:in `each'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/slug_generator.rb:19:in `generate'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/friendly_id-5.5.1/lib/friendly_id/slugged.rb:357:in `set_slug'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/bundler/gems/friendly_id-mobility-45392451cdaf/lib/friendly_id/mobility.rb:53:in `set_slug'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:361:in `block in make_lambda'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:178:in `block in call'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:667:in `block (2 levels) in default_terminator'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:666:in `catch'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:666:in `block in default_terminator'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:179:in `call'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:558:in `block in invoke_before'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:558:in `each'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:558:in `invoke_before'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:108:in `run_callbacks'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activesupport-8.0.0/lib/active_support/callbacks.rb:912:in `_run_validation_callbacks'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activemodel-8.0.0/lib/active_model/validations/callbacks.rb:115:in `run_validations!'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activemodel-8.0.0/lib/active_model/validations.rb:365:in `valid?'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/gems/activerecord-8.0.0/lib/active_record/validations.rb:71:in `valid?'
     # /cache/nicolas/concerto/ruby-wip-rails8/ruby/3.3.0/bundler/gems/action_form-55bc53c7830b/lib/action_form/form_helpers.rb:21:in `valid?'
     # ./app/concepts/application_form.rb:8:in `call'

Thank you!

[aseroff]

Last blocker for a rails 8 upgrade...hope this issue gets attention soon.

[SebastienHugues]

Last blocker for me as well. @shioyama do you know when you will have some time to look at this issue? Thanks a lot! :-)