Including assets from node_modules fails

[cseelus]

I use a SASS file , lets call it pdf.css, which is configured via assets.rb to be precompiled:

Rails.application.config.assets.precompile += %w( pdf.css )

When uncommenting the Yarn node_modules folder in assets.rb …

Rails.application.config.assets.paths << Rails.root.join('node_modules')

… and including files from node_modules into the pdf stylesheet, it gets compiled to CSS and can be included normally in any Rails template.

When I include the same pdf.css with a Wicked PDF template though, I get the following error, see also #680:

undefined method `start_with?' for nil:NilClass
[…]/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:113:in `split_subpath'
[…]/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:128:in `block in paths_split'
[…]/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:127:in `each'
[…]/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:127:in `paths_split'
[…]/gems/sprockets-3.7.2/lib/sprockets/resolve.rb:96:in `resolve_relative_path'
[…]/gems/sprockets-3.7.2/lib/sprockets/resolve.rb:33:in `resolve'
[…]/gems/sprockets-3.7.2/lib/sprockets/legacy.rb:66:in `resolve_with_compat'
[…]/gems/sprockets-3.7.2/lib/sprockets/base.rb:64:in `find_asset'
[…]/gems/sprockets-3.7.2/lib/sprockets/environment.rb:30:in `find_asset'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:77:in `find_asset'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:70:in `asset_pathname'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:47:in `wicked_pdf_asset_path'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:25:in `block in wicked_pdf_stylesheet_link_tag'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:21:in `gsub'
[…]/gems/wicked_pdf-1.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:21:in `wicked_pdf_stylesheet_link_tag'