Fix ActionViewExtension not available during eager loading

[fcatuhe]

Summary

• Fix MoneyRails::ActionViewExtension not being available during eager loading (config.eager_load = true)
• Use Ruby's autoload to define the constant immediately at require time, deferring file loading until first access

Problem

When a Rails app has config.eager_load = true (production), referencing MoneyRails::ActionViewExtension raises:

uninitialized constant MoneyRails::ActionViewExtension

This happens because the extension is only loaded inside an ActiveSupport.on_load(:action_view) callback. During eager loading, app files (like decorators) that include MoneyRails::ActionViewExtension are loaded before ActionView triggers the callback.

Solution

Use autoload to register the constant immediately while deferring the actual file load:

module MoneyRails
  autoload :ActionViewExtension, 'money-rails/helpers/action_view_extension'
end

The on_load(:action_view) callback still includes the helper into ActionView::Base, but no longer needs to handle the require.

Test plan

• Verified existing test suite passes
• Can be tested by creating a decorator that includes MoneyRails::ActionViewExtension in an app with config.eager_load = true

Fixes #614

[sunny]

Awesome fix. Can you add a CHANGELOG entry as well? 🙏🏻

[fcatuhe]

Sure, pushed the CHANGELOG entry with similar convention. Thanks!

[fcatuhe]

@sunny, I'm happy to add a test if you'd like. I'm thinking a simple autoload verification in spec/helpers/action_view_extension_spec.rb:

describe 'MoneyRails::ActionViewExtension' do
  describe 'autoload' do
    it 'is registered via autoload for eager loading compatibility' do
      expect(MoneyRails.autoload?(:ActionViewExtension)).to eq('money-rails/helpers/action_view_extension')
    end
  end
end

This would catch if someone accidentally removes the autoload line. It doesn't test actual eager loading behavior (that would require a subprocess with eager_load = true), but it documents the fix and guards against regression.

Let me know if you'd like me to add this.

[sunny]

Yeah, would love that! It’ll make sure future refactors think about the eager-loading use-case.

[fcatuhe]

Done and ready for review.

[yukideluxe]

Thanks!