Drop Compass support, bump minimum Sass version

Compass is no longer maintained and hasn't seen a release for 3 years.
The compass gem locks Sass to version < 3.5.

However, we now need Sass v3.5+ due to

sass/sass#2383

This commit removes compass support and bumps minimum Ruby Sass version
to v3.5.2.

Author: glebm

CHANGELOG.md

@@ -6,6 +6,9 @@ The changelog only includes changes specific to the RubyGem.
 The Bootstrap framework changes can be found in [the Releases section of twbs/bootstrap](https://github.com/twbs/bootstrap/releases).
 Release announcement posts on [the official Bootstrap blog](http://blog.getbootstrap.com) contain summaries of the most noteworthy changes made in each release of Bootstrap.
 
+# 4.0.0.beta
+
+Compass is no longer supported.
 
 # 4.0.0.alpha3.1
 

README.md

@@ -1,6 +1,6 @@
 # Bootstrap Ruby Gem [![Build Status](https://travis-ci.org/twbs/bootstrap-rubygem.svg?branch=master)](https://travis-ci.org/twbs/bootstrap-rubygem) [![Gem](https://img.shields.io/gem/v/bootstrap.svg)](https://rubygems.org/gems/bootstrap)
 
-[Bootstrap 4][bootstrap-home] ruby gem for Ruby on Rails (Sprockets), Hanami (formerly Lotus) and Compass.
+[Bootstrap 4][bootstrap-home] ruby gem for Ruby on Rails (Sprockets) and Hanami (formerly Lotus).
 
 For Sass versions of Bootstrap 3 and 2 see [bootstrap-sass](https://github.com/twbs/bootstrap-sass) instead.
 
@@ -9,7 +9,7 @@ For Sass versions of Bootstrap 3 and 2 see [bootstrap-sass](https://github.com/t
 Please see the appropriate guide for your environment of choice:
 
 * [Ruby on Rails 4+](#a-ruby-on-rails) or other Sprockets environment.
-* [Compass](#b-compass-without-rails) not on Rails.
+* [Other Ruby frameworks](#b-other-ruby-frameworks) not on Rails.
 
 
 ### a. Ruby on Rails
@@ -73,47 +73,14 @@ the concatenated `bootstrap` for faster compilation:
 //= require bootstrap
 ```
 
-### b. Compass without Rails
+### b. Other Ruby frameworks
 
-Install the gem:
+If your framework uses Sprockets or Hanami,
+the assets will be registered with Sprockets when the gem is required,
+and you can use them as per the Rails section of the guide.
 
-```console
-$ gem install bootstrap -v 4.0.0.beta
-```
-
-**If you have an existing Compass project:**
-
-1. Require `bootstrap` in `config.rb`:
-
-    ```ruby
-    require 'bootstrap'
-    ```
-
-2. Install Bootstrap with:
-
-    ```console
-    $ bundle exec compass install bootstrap
-    ```
-
-**If you are creating a new Compass project, you can generate it with bootstrap support:**
-
-```console
-$ bundle exec compass create my-new-project -r bootstrap --using bootstrap
-```
-
-or, alternatively, if you're not using a Gemfile for your dependencies:
-
-```console
-$ compass create my-new-project -r bootstrap --using bootstrap
-```
-
-This will create a new Compass project with the following files in it:
-
-* [styles.scss](/templates/project/styles.scss) - main project Sass file, imports Bootstrap and variables.
-* [_bootstrap-variables.scss](/templates/project/_bootstrap-variables.scss) - all of Bootstrap variables, override them here.
-
-Some bootstrap mixins may conflict with the Compass ones.
-If this happens, change the import order so that Compass mixins are loaded later.
+Otherwise you may need to register the assets manually.
+Refer to your framework's documentation on the subject.
 
 ## Configuration
 

bootstrap.gemspec

@@ -13,13 +13,12 @@ Gem::Specification.new do |s|
 
   s.add_runtime_dependency 'popper_js', '>= 1.12.3', '< 2'
 
-  s.add_runtime_dependency 'sass', '>= 3.4.19'
+  s.add_runtime_dependency 'sass', '>= 3.5.2'
   s.add_runtime_dependency 'autoprefixer-rails', '>= 6.0.3'
 
   # Testing dependencies
   s.add_development_dependency 'minitest', '~> 5.8.0'
   s.add_development_dependency 'minitest-reporters', '~> 1.0.5'
-  s.add_development_dependency 'compass', '~> 1.0.3'
   s.add_development_dependency 'term-ansicolor'
   # Integration testing
   s.add_development_dependency 'capybara', '>= 2.6.0'

lib/bootstrap.rb

@@ -5,8 +5,6 @@ module Bootstrap
   class << self
     # Inspired by Kaminari
     def load!
-      register_compass_extension if compass?
-
       if rails?
         register_rails_engine
       elsif hanami?
@@ -40,10 +38,6 @@ def sprockets?
       defined?(::Sprockets)
     end
 
-    def compass?
-      defined?(::Compass::Frameworks)
-    end
-
     def rails?
       defined?(::Rails)
     end
@@ -60,16 +54,6 @@ def configure_sass
       ::Sass.load_paths << stylesheets_path
     end
 
-    def register_compass_extension
-      ::Compass::Frameworks.register(
-          'bootstrap',
-          :version               => Bootstrap::VERSION,
-          :path                  => gem_path,
-          :stylesheets_directory => stylesheets_path,
-          :templates_directory   => File.join(gem_path, 'templates')
-      )
-    end
-
     def register_rails_engine
       require 'bootstrap/engine'
     end

tasks/updater/scss.rb

@@ -21,18 +21,6 @@ def update_scss_assets
         # As we moved the files, adjust imports accordingly.
         File.write to, File.read(to).gsub(/ "/, ' "bootstrap/')
       end
-
-      log_status 'Generating variable template file'
-      save_file 'templates/project/_bootstrap-variables.scss',
-                "// Override Bootstrap variables here (defaults from bootstrap v#{upstream_version}):\n" +
-                    File.read("#{save_to}/_variables.scss").
-                        # The instructions in the file header are replaced with the line above
-                        lines[4..-1].
-                        join.
-                        # Comment out the assignments
-                        gsub(/^(?=[$@)}]|[ ]{2})/, '// ').
-                        # Remove the !default modifier
-                        gsub(/ !default/, '')
     end
   end
 end