Server rendering crashes in production with sprockets-rails < 2.2.2

[tf]

#430 introduced the ManifestContainer which uses Rails.application.assets_manifest. This method was introduced by sprockets-rails 2.2.2. If Rails.config.assets.compile is set to false (which it is by default in production) SprocketsRenderer no longer uses EnvironmentContainer and causes the exception:

ActionView::Template::Error (undefined method `assets_manifest' for #<Xxx::Application:0x007f5464c7b180>):

  react-rails (1.6.2) lib/react/server_rendering/manifest_container.rb:9:in `initialize'
  react-rails (1.6.2) lib/react/server_rendering/sprockets_renderer.rb:70:in `new'
  react-rails (1.6.2) lib/react/server_rendering/sprockets_renderer.rb:70:in `asset_container'
  react-rails (1.6.2) lib/react/server_rendering/sprockets_renderer.rb:22:in `block in initialize'

I can see two possibilities:

1. Fallback to EnvironmentContainer for sprockets-rails < 2.2.2
2. Make the sprockets-rails dependency explicit

There are Rails version though (e.g. 4.0.5) that depend on sprocket-rails ~> 2.0.0.

[rmosolgo]

Hmm, I see what you mean, that logic for choosing a container could be improved. Option 1. sounds best to me, do you want to give it a try?

In the meantime, I think you can work around it by manually choosing EnvironmentContainer:

React::ServerRendering::SprocketsRenderer.asset_container_class = React::ServerRendering::SprocketsRenderer::EnvironmentContainer

[tf]

Yes, that's what I did. I can submit a PR. Do you want me to feature detect assets_manifest with repond_to? or check Sprockets::Rails::VERSION?

[rmosolgo]

feature detection sounds good to me!

[tf]

I'll submitted a PR (#545). Would be great if you could take a look.