Make the API for compression consistent between JS and CSS. By default, users...

Make the API for compression consistent between JS and CSS. By default, users just need to say whether they want compression or not, and a default will be chosen by a Railtie. In the case of CSS, this default is already chosen by the sass-rails gem.

Users can still explicitly choose a compressor in their application.rb if they have a preference, but will usually want to let plugins choose defaults in their Railties.

actionpack/lib/sprockets/railtie.rb

@@ -63,8 +63,12 @@ def asset_environment(app)
 
         env.logger = Rails.logger
 
-        env.js_compressor  = expand_js_compressor(assets.js_compressor)
-        env.css_compressor = expand_css_compressor(assets.css_compressor)
+        if assets.compress
+          # temporarily hardcode default JS compressor to uglify. Soon, it will work
+          # the same as SCSS, where a default plugin sets the default.
+          env.js_compressor  = expand_js_compressor(assets.js_compressor || :uglifier)
+          env.css_compressor = expand_css_compressor(assets.css_compressor)
+        end
 
         env
       end

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

@@ -14,9 +14,6 @@
   # Compress JavaScripts and CSS
   config.assets.compress = true
 
-  # Specify the default JavaScript compressor
-  config.assets.js_compressor  = :uglifier
-
   # Specifies the header that your server uses for sending files
   # (comment out if your front-end server doesn't support this)
   config.action_dispatch.x_sendfile_header = "X-Sendfile" # Use 'X-Accel-Redirect' for nginx