Change compressor API so that plugins can register default compressors for their stylesheet or JS engines and still allow the user to turn off compression

actionpack/lib/sprockets/railtie.rb

@@ -26,7 +26,8 @@ module Sprockets
 
     # We need to configure this after initialization to ensure we collect
     # paths from all engines. This hook is invoked exactly before routes
-    # are compiled.
+    # are compiled, and so that other Railties have an opportunity to
+    # register compressors.
     config.after_initialize do |app|
       assets = app.config.assets
       next unless assets.enabled
@@ -57,8 +58,8 @@ module Sprockets
       env.static_root = File.join(app.root.join("public"), assets.prefix)
       env.paths.concat assets.paths
       env.logger = Rails.logger
-      env.js_compressor = expand_js_compressor(assets.js_compressor)
-      env.css_compressor = expand_css_compressor(assets.css_compressor)
+      env.js_compressor = expand_js_compressor(assets.js_compressor) if app.assets.compress
+      env.css_compressor = expand_css_compressor(assets.css_compressor) if app.assets.compress
       env
     end
 

railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt

@@ -21,4 +21,7 @@
 
   # Only use best-standards-support built into browsers
   config.action_dispatch.best_standards_support = :builtin
+
+  # Do not compress assets
+  config.assets.compress = false
 end

railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt

@@ -11,9 +11,11 @@
   # Disable Rails's static asset server (Apache or nginx will already do this)
   config.serve_static_assets = false
 
-  # Compress both stylesheets and JavaScripts
+  # Compress JavaScripts and CSS
+  config.assets.compress = true
+
+  # Specify the default JavaScript compressor
   config.assets.js_compressor  = :uglifier
-  config.assets.css_compressor = :scss
 
   # Specifies the header that your server uses for sending files
   # (comment out if your front-end server doesn't support this)