fix for sprockets-3.0.x

[masarakki]

after sprockets-3.0.x, I can't find depend_on files when assets.paths dosen't include directory.

[le0pard]

Hello, @masarakki . Thanks for pull request. But also need fix tests, because https://github.com/rails/sprockets/blob/v3.0.0/lib/sprockets/context.rb also changed in sprockets 3.0.

[masarakki]

How can I write spec for both 3.0.x and 2.x? use Appraisal?

[le0pard]

Yes, you can use Appraisal and also you can write conditions inside specs (you have access to Sprockets::VERSION, like Sprockets::VERSION =~ /\A3\.\d+\.\d+\z/)

[le0pard]

Thanks @masarakki, this pull request looks like good. Need review from @bogdan (I think better remove 1.9.3 from CI matrix - it is already unsupported).

[bogdan]

Why do we need to add config to assets path? Can you describe with details?

[le0pard]

#143 (comment)

[masarakki]

depend_on of Sprockets 3.0.x check the requested file is under the assets_paths

https://github.com/rails/sprockets/blob/master/lib/sprockets/resolve.rb#L69

[le0pard]

Hello @masarakki .

I think we don't need add

initializer 'js-routes.append_assets_path', group: :all, after: :append_assets_path do |app|
  app.config.assets.paths.unshift Rails.root.join('config').to_s
end

to assets_paths, because we render js-routes from https://github.com/railsware/js-routes/blob/master/app/assets/javascripts/js-routes.js.erb file, which is located in assets_path (I hope). Does it work without this?

[pbhogan]

It is technically necessary since sprockets checks that all dependencies are themselves under the asset paths and routes.rb is not. However, adding config to the asset paths is not good in my opinion. It may have other unwanted side effects.

A mechanism seems to exist to declare external environmental dependencies in sprockets 3. I've taken a shot at implementing using it myself and this seems to work:
https://github.com/pbhogan/js-routes/blob/master/lib/js_routes/engine.rb

I've left the original register_preprocessor call in since it is necessary for sprockets 2 but is just rejected by sprockets 3 harmlessly in depend_on here:
https://github.com/sstephenson/sprockets/blob/v3.0.0.beta.8/lib/sprockets/resolve.rb#L65

[masarakki]

@pbhogan
it seems good!!

[masarakki]

update code.

[le0pard]

Little typo: file-digest:// should be.

[masarakki]

oh, thx!

[le0pard]

waiting @bogdan

[bogdan]

I think remove those files in before is enough. Why do you think after makes sense?

[bogdan]

Looks good in general. Only one small comment regarding rspec callbacks.

[le0pard]

ping @bogdan :)