Fix Missing Import in Rails

Missing Import Errors in Rails

Rails uses Zeitwerk for autoloading, which means you rarely need explicit require statements. When you see NameError: uninitialized constant X, something is misconfigured.

Zeitwerk Naming Conventions

Zeitwerk expects class names to match file paths:

# app/models/user.rb → User
# app/services/payment_processor.rb → PaymentProcessor
# app/services/stripe/charge_service.rb → Stripe::ChargeService

# BAD — file name doesn't match class
# app/services/stripeChargeService.rb → expects StripeChargeService
# but you defined Stripe::ChargeService

Check Autoload Paths

# config/application.rb
config.autoload_paths += %W[#{config.root}/lib]
config.eager_load_paths += %W[#{config.root}/lib]

Common Errors

Constant not found in development but works in production (or vice versa):

# Check for naming issues
bin/rails zeitwerk:check

Gem class not available:

# Gemfile — make sure it's not in the wrong group
gem 'sidekiq'  # Available everywhere

# NOT:
group :development do
  gem 'sidekiq'  # Won't be available in production!
end

Explicit Require

For code outside autoload paths:

# For non-autoloaded files
require 'csv'
require 'net/http'
require_relative '../lib/custom_parser'

Concerns and Modules

# app/models/concerns/searchable.rb
module Searchable
  extend ActiveSupport::Concern
  # ...
end

# app/models/product.rb
class Product < ApplicationRecord
  include Searchable  # Autoloaded from concerns/
end

Bugsly captures NameError and LoadError in Rails with the constant name and backtrace, showing exactly where the missing reference was triggered.