I’m facing an issue with a custom generator in Rails 7.1, and it’s been quite confusing. I could really use some help!

I created a custom generator with the following structure after running rails g generator query:

create  lib/generators/query
create  lib/generators/query/query_generator.rb
create  lib/generators/query/USAGE
create  lib/generators/query/templates

Here’s the basic structure of my generator:

class QueryGenerator < Rails::Generators::NamedBase
  source_root File.expand_path("templates", __dir__)

  # rest of the code
end

Everything works perfectly in my development environment. I can run rails generate query user without any issues.

However, when deploying to production with Dokku, I encountered two major errors:

1. NameError: Uninitialized constant Rails::Generators
   This was triggered by the QueryGenerator class. I fixed it by adding require ‘rails/generators’ at the top of lib/generators/query/query_generator.rb.

2. Zeitwerk::NameError: Expected file to define constant Generators::Query::QueryGenerator
   To resolve this, I adjusted the structure as follows:

require 'rails/generators'

module Generators
  module Query
    class QueryGenerator < Rails::Generators::NamedBase
      # ... rest of the code ...
    end
  end
end

After making these changes, running RAILS_ENV=production bin/rails zeitwerk:check showed no errors, which seemed promising.

Despite everything appearing to work, when I try to run the generator with rails g query User, I get the following error:

Could not find generator 'query'. (Rails::Command::CorrectableNameError)
Run `bin/rails generate --help` for more options.

It seems like there’s a conflict between how Zeitwerk expects things to be loaded and how Rails is recognizing the generator.

Has anyone encountered something similar or have any ideas on how to resolve this? I’d appreciate any advice or guidance. Thanks in advance!

Solution

Hey everyone, I managed to solve the issue I was facing! 🎉

I fixed it by changing the file structure from:

lib/generators/query/query_generator.rb
lib/generators/query/templates/query.rb.tt

To:

lib/rails/generators/query_generator.rb
lib/rails/generators/templates/query.rb.tt

And I updated the generator code as follows:

# frozen_string_literal: true

require 'rails/generators'

module Rails
  module Generators
    class QueryGenerator < Rails::Generators::NamedBase
      # Your code here...
    end
  end
end

This new structure and code resolved the issue in production, and the generator now works as expected.