NoMethodError: private method `importmap=' called

[javierav]

I'm updating importmap-rails from 0.6.1 to 0.7.6 and I get the following error:

NoMethodError: private method `importmap=' called for #<XXXX::Application:0x000056001ecded98>
/home/runner/work/xxxx/xxxx/vendor/bundle/ruby/2.6.0/gems/importmap-rails-0.7.6/lib/importmap/engine.rb:14:in `block in <class:Engine>'

• importmap-rails 0.7.6
• stimulus-rails 0.6.0
• turbo-rails 0.8.1
• rails 6.1.4.1

# config/importmap.rb

pin 'bootstrap', to: 'https://cdn.skypack.dev/bootstrap'
pin '@hotwired/turbo-rails', to: 'turbo.js'
pin '@hotwired/stimulus', to: 'stimulus.js'
pin '@hotwired/stimulus-autoloader', to: 'stimulus-autoloader.js'
pin '@hotwired/stimulus-importmap-autoloader', to: 'stimulus-importmap-autoloader.js'
pin '@rails/activestorage', to: 'https://cdn.skypack.dev/@rails/activestorage'
pin '@rails/actioncable', to: 'https://cdn.skypack.dev/@rails/actioncable'
pin 'trix', to: 'https://cdn.skypack.dev/trix'
pin '@rails/actiontext', to: 'https://cdn.skypack.dev/@rails/actiontext'

pin_all_from 'app/assets/javascripts/channels', under: 'channels'
pin_all_from 'app/assets/javascripts/controllers', under: 'controllers'

pin 'application'

[dhh]

You're calling Rails.application.config.importmap somewhere and that needs to be changed to Rails.application.importmap.

[javierav]

My App does not have any reference to Rails.application.config.importmap:

~/app $ grep -nir 'config.importmap' *
~/app $

The failure happen in this point of importmap-rails/lib/importmap/engine.rb:

initializer "importmap" do |app|
  app.importmap = Importmap::Map.new.draw("config/importmap.rb")
end

For some reason app.importmap and app.importmap= are private methods!

[dhh]

Do you have stimulus-rails or turbo-rails installed? If so, make sure you're running the latest versions.

[javierav]

@dhh Yes, I'm using the latest available versions...

importmap-rails 0.7.6
stimulus-rails 0.6.0
turbo-rails 0.8.1
rails 6.1.4.1

[dhh]

Is importmap-rails listed before the other two gems in your Gemfile?

[dhh]

Can't replicate when I do:

rails new sport
cd sport
bundle add importmap-rails
bin/rails importmap:install
bundle add hotwire-rails
bin/rails Hotwire:install

That's on Rails 6.1.4.1.

[javierav]

Is importmap-rails listed before the other two gems in your Gemfile?

Yes, it's listed before!

Can't replicate when I do:

I can replicate it following your installation steps:

rails new sport -> OK
cd sport-> OK
bundle add importmap-rails -> OK
bin/rails importmap:install -> FAILURE

$ bin/rails importmap:install
rails aborted!
NoMethodError: private method `importmap=' called for #<Sport::Application:0x00007f97bdf9f2c0>
/Users/javierav/Desarrollo/sport/config/environment.rb:5:in `<main>'
/Users/javierav/Desarrollo/sport/bin/rails:5:in `<top (required)>'
/Users/javierav/Desarrollo/sport/bin/spring:10:in `require'
/Users/javierav/Desarrollo/sport/bin/spring:10:in `block in <top (required)>'
/Users/javierav/Desarrollo/sport/bin/spring:7:in `tap'
/Users/javierav/Desarrollo/sport/bin/spring:7:in `<top (required)>'
Tasks: TOP => app:template => environment
(See full trace by running task with --trace)

I'm using MRI Ruby: ruby 2.6.7p197 (2021-04-05 revision 67941) [x86_64-darwin20]

[dhh]

Weird. Try Ruby 2.7.

[javierav]

ruby 2.6.7p197 (2021-04-05 revision 67941) [x86_64-darwin20] -> FAILURE
ruby 2.6.8p205 (2021-07-07 revision 67951) [x86_64-darwin20] -> FAILURE
ruby 2.7.4p191 (2021-07-07 revision a21a3b7d23) [x86_64-darwin20] -> OK

Any problem with Ruby 2.6.x and Rails::Application.send(:attr_accessor, :importmap)? 🤔

[jefflasslett]

@javierav . I've had this same problem on ruby 2.6.8. Unfortunately I am stuck here until jruby 9.4.0.0 is released.
There doesn't seem to be anything wrong with the Rails::Application.send(:attr_accessor, :importmap) call, other than it doesn't seem to get executed when run under ruby < 2.7.

My workaround (that seems to be working so far) is to simply add attr_accessor :importmap in the application class definition in config/application.rb.

[dhh]

Rails 7 is going to require Ruby 2.7 as the minimum.

[terencechow]

I know this is closed but I just had the same issue with a jruby app and sprockets-rails. Jruby 3 follows ruby 2.6. Specifically I got

NoMethodError:
    private method `assets=` called for #<RailsRoot::Application:0x47e7b7>
   # ...'path/to/sprockets-rails/lib/sprockets/railtie.rb:209

Inside sprockets I see assets defined with attr_accessor :assets which is the same functionality used in this library.

Adding attr_accessor :assets in my decendent class RailsRoot::Application seems to have fixed the issue.

[rootcfg]

Hello DHH!

Using java is often a must. Not always the technology stack implies the possibility of using microservices on Docker or similar. and cruby is not a fact that they will approve. Could you design your solution with the current stable version of jruby and jrails respectively in mind? You may have forgotten about things like .war but there are many places on earth where it is used and quite successfully.

Regards DD

[headius]

JRuby 9.4 will be out soon with support for Ruby 3.1 and Rails 7.