[jruby] `uninitialized constant Prism::ParseResult::Comments` when using `attach_comments!`

[davidwessman]

Hello 🙂

I am working on a Prism-based scanner for i18n-tasks but our tests are failing on jruby after we started using attach_comments!.

https://github.com/glebm/i18n-tasks/actions/runs/17445820795/job/49539929653

I18n::Tasks::CommandError:
        Error scanning app/views/application/comments.html.erb: uninitialized constant Prism::ParseResult::Comments
      # ./vendor/bundle/jruby/3.4.0/gems/prism-1.4.0/lib/prism/parse_result.rb:764:in 'attach_comments!'
      # ./lib/i18n/tasks/scanners/ruby_scanner.rb:164:in 'process_prism_results'
      # ./lib/i18n/tasks/scanners/erb_ast_scanner.rb:106:in 'process_code'
      # ./lib/i18n/tasks/scanners/erb_ast_scanner.rb:94:in 'block in prism_parse_file'
      # ./lib/i18n/tasks/scanners/erb_ast_scanner.rb:87:in 'prism_parse_file'
      # ./lib/i18n/tasks/scanners/ruby_scanner.rb:30:in 'scan_file'
      # ./lib/i18n/tasks/scanners/file_scanner.rb:27:in 'block in keys'
      # ./lib/i18n/tasks/scanners/files/file_finder.rb:30:in 'traverse_files'
      # ./lib/i18n/tasks/scanners/file_scanner.rb:57:in 'traverse_files'
      # ./lib/i18n/tasks/scanners/file_scanner.rb:26:in 'keys'
      # ./lib/i18n/tasks/scanners/scanner_multiplexer.rb:34:in 'block in collect_results'
      # ------------------
      # --- Caused by: ---
      # NameError:
      #   uninitialized constant Prism::ParseResult::Comments
      #   ./vendor/bundle/jruby/3.4.0/gems/prism-1.4.0/lib/prism/parse_result.rb:764:in 'attach_comments!'
end

Is it a bug or is there anything special we need to do for jruby?

[eregon]

It should be automatically loaded via https://github.com/ruby/prism/blob/v1.4.0/lib/prism/parse_result.rb#L740.
And that file itself is always loaded via https://github.com/ruby/prism/blob/v1.4.0/lib/prism.rb#L73.
So maybe a JRuby autoload-related bug?

You could try on TruffleRuby to figure out if it's possibly related to the different code path in Prism for CRuby and non-CRuby.

[enebo]

I think this is a JRuby bug with autoload + private_constant. If I comment out the private_constant line for Comments specs run without error. Looking into this.

[enebo]

This is a JRuby problem (@davidwessman). Follow on jruby/jruby#8994. I will close this on prism since it is not a prism issue. Thanks for finding this problem. We will fix it for 10.0.0.3.

[enebo]

@kddnewton I am not sure if I put the correct labels for this. Let me know if not so I don't make the same mistake next time.