Rails.application.config.view_component.preview_paths issue

[alec-c4]

Hi!
As described here https://viewcomponent.org/guide/previews.html#use-with-rspec - to use previews with rspec you just need to configure paths

# config/application.rb
config.view_component.previews.paths << "#{Rails.root}/spec/components/previews"

I have the following initializer

Rails.application.config.view_component.preview_paths << Rails.root.join("spec/components/previews").to_s
Rails.application.config.view_component.default_preview_layout = "component_preview"
Rails.application.config.view_component.generate.sidecar = true

and when I try to start app I see

cosmoport ❯ rails console                                                                                                                           [master] ≡5 !6 ?30 
/Users/alec/Code/Internal/CosmoPort/cosmoport/config/initializers/view_component.rb:1:in '<main>': undefined method '<<' for nil (NoMethodError)

Rails.application.config.view_component.preview_paths << Rails.root.join("spec/components/previews").to_s
                                                      ^^
        from /Users/alec/.local/share/mise/installs/ruby/3.4.5/lib/ruby/gems/3.4.0/gems/railties-8.0.2/lib/rails/engine.rb:693:in 'Kernel#load'
        from /Users/alec/.local/share/mise/installs/ruby/3.4.5/lib/ruby/gems/3.4.0/gems/railties-8.0.2/lib/rails/engine.rb:693:in 'block in Rails::Engine#load_config_in
itializer'
        from /Users/alec/.local/share/mise/installs/ruby/3.4.5/lib/ruby/gems/3.4.0/gems/activesupport-8.0.2/lib/active_support/notifications.rb:212:in 'ActiveSupport::N
otifications.instrument'

But Rails.root.join("spec/components/previews").to_s is set

cosmoport ❯ rails console                                                                                                                         


Type 'jobs_help' to see how to connect to the available job servers to manage jobs

Loading development environment (Rails 8.0.2)
cosmoport(dev)> Rails.root.join("spec/components/previews").to_s
cosmoport(dev)> 
=> "/Users/alec/Code/Internal/CosmoPort/cosmoport/spec/components/previews"
cosmoport(dev)> 

Whats wrong?

[joelhawksley]

Thanks for taking the time to file an issue!

Rails.application.config.view_component.preview_paths should be Rails.application.config.view_component.previews.paths.

[alec-c4]

@joelhawksley, may I ask you to update documentation? Maybe we need an upgrade guide from 3.x to 4.x? How can I help?

[joelhawksley]

@alec-c4 I see the new syntax in the docs you linked, did we miss a spot?

As for an upgrade guide, this change is in the 4.0.0 changelog, is there somewhere else we should note it?

[noproblemwiththat]

This bit me too, in case it helps anyone else, my previous configuration (for LookBook)

config.view_component.generate.sidecar = true
config.view_component.generate.preview_path = 'spec/components/previews'
config.view_component.show_previews = true
config.view_component.default_preview_layout = 'component'
config.view_component.preview_paths << Rails.root.join('spec/components/previews')

works with 4.0.0 when updated to

config.view_component.generate.sidecar = true
config.view_component.generate.preview_path = 'spec/components/previews'
config.view_component.previews.enabled = true
config.view_component.previews.default_layout = 'component'
config.view_component.previews.paths  << Rails.root.join('spec/components/previews')