Process css files so that they get digested paths for asset files

[jcoyne]

This is required so that we can use cssbundling-rails and reference images that will receive digested paths

[dhh]

Test errors?

[jcoyne]

Any idea how to run those tests? I see:

 $ bundle exec rake
/Users/jcoyne85/.rbenv/versions/2.7.2/bin/ruby -w -I"lib:lib" /Users/jcoyne85/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/rake-13.0.6/lib/rake/rake_test_loader.rb "test/test_asset_url_processor.rb" "test/test_helper.rb" "test/test_quiet_assets.rb" "test/test_railtie.rb" "test/test_task.rb"
Run options: --seed 20295

# Running:

..............................................................................................................................................................

Finished in 9.315093s, 16.9617 runs/s, 83.3057 assertions/s.
158 runs, 776 assertions, 0 failures, 0 errors, 0 skips

[dhh]

Seems like it's one specific failure:

Error:
13
TestRailtie#test_task_precompile:
14
ArgumentError: nil is not a valid asset source
15
    /home/runner/bundle/ruby/2.5.0/gems/actionview-5.2.6/lib/action_view/helpers/asset_url_helper.rb:184:in `asset_path'
16
    /home/runner/work/sprockets-rails/sprockets-rails/lib/sprockets/rails/asset_url_processor.rb:9:in `call'
17

[valeronm]

@jcoyne @dhh Looks like the test failed because of this commit 408aae2. Versions with and without block are not interchangeable for this logic. $1 is calculated before calling #gsub in version without block and it contains value of any previously executed Regex.

[jrochkind]

Should this make it no longer necessary to use eg asset-url() helper introduced by sass-rails? all url() references in CSS are just transparently processed to use appropriate digested filenames automatically now? If you have a url() reference in CSS that is processed by sprockets, it will now be automatically transformed to use an appropriate path? Maybe only if it looks like a relative path?

I think something in this change broke one of my apps, which is now having trouble resolving some assets. I am trying to figure out what happened, and will file an issue if I can figure out more. But I'm trying to make sure I understand the intent and effect of this change, so asking here. Thanks!

[MtnBiker]

Just read the documentation and don't see a better way to have images show up. I'm using leaflet.js and some images are needed. I copied node_module/leaflet/dist/images/ to /public.