replacing sassc with dartsass-sprockets

[jonmchan]

sassc is deprecated. Replacing sassc with dart-sass is the simplest and most straightforward methodology to keep using sass. The gem dartsass-sprockets provides a drop-in replacement implementing almost everything that sassc-rails offered utilizing the same namespace and method signatures.

There are several deprecation errors that needs to be addressed with the newer version of sass, but it would be good to upgrade to the latest version of the library.

These errors can be addressed in a future PR.

Deprecation errors:

    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/_default.sass 60:17   @import
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/application.scss 1:9  root stylesheet
Deprecation Warning: Using / for division outside of calc() is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($rep-grid-gutter, -2) or calc($rep-grid-gutter / -2)

More info and automated migrator: https://sass-lang.com/d/slash-div

   ╷
61 │   margin-right: ($rep-grid-gutter / -2)
   │                  ^^^^^^^^^^^^^^^^^^^^^
   ╵
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/_default.sass 61:18   @import
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/application.scss 1:9  root stylesheet
Deprecation Warning: Using / for division outside of calc() is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($rep-grid-gutter, 2) or calc($rep-grid-gutter / 2)

More info and automated migrator: https://sass-lang.com/d/slash-div

   ╷
67 │   padding-right: ($rep-grid-gutter / 2)
   │                   ^^^^^^^^^^^^^^^^^^^^
   ╵
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/_default.sass 67:19   @import
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/application.scss 1:9  root stylesheet
Deprecation Warning: Using / for division outside of calc() is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($rep-grid-gutter, 2) or calc($rep-grid-gutter / 2)

More info and automated migrator: https://sass-lang.com/d/slash-div

   ╷
68 │   padding-left: ($rep-grid-gutter / 2)
   │                  ^^^^^^^^^^^^^^^^^^^^
   ╵
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/_default.sass 68:18   @import
    /usr/local/bundle/bundler/gems/rails_email_preview-0babc0ff21e4/app/assets/stylesheets/rails_email_preview/application.scss 1:9  root stylesheet
Deprecation Warning: Using / for division outside of calc() is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($col, 12) or calc($col / 12)

More info and automated migrator: https://sass-lang.com/d/slash-div

   ╷
75 │       width: percentage($col / 12)
   │                         ^^^^^^^^^
   ╵

[glebm]

There appear to be quite a few Sass engines out there. Perhaps we can take a similar approach to the bootstrap ruby gem and support more of them?

https://github.com/twbs/bootstrap-rubygem/blob/main/lib/bootstrap/engine.rb

[jonmchan]

@glebm I'd be happy to update the PR with the library loading script. I'll add similar verbiage to the README as the bootstrap gem.

[jonmchan]

Ruby 3.0 and below are end of life and no longer supported. Should legacy versions of ruby be removed from the testing matrix? Only Rails 7.1, 7.0, and 6.1 is receiving support from the official rails team. Should Rails 5.0 and 4.2 be removed from the testing matrix?

[glebm]

Yep, please remove them

[jonmchan]

@glebm there's a dependency issue with rails_7_1 and ruby_version 3.1, otherwise all the tests pass. Here is the failed run:

https://github.com/wayhomeservices/rails_email_preview/actions/runs/9921493773/job/27409522524

I commented it out in the PR. I'm not 100% sure it is worth tracking down or not.

[glebm]

Thank you for your effort and patience, Jonathan! Merged!