Instead of disabling JS compression everywhere, only do so when staging r.js input files

Fixes #176. Credit @wuservices for the idea.

Author: carsomyr

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    requirejs-rails (0.9.3)
+    requirejs-rails (0.9.4)
       railties (>= 3.1.1)
 
 GEM

lib/requirejs/rails/engine.rb

@@ -20,12 +20,13 @@ class Engine < ::Rails::Engine
 
         config.assets.precompile += config.requirejs.precompile
 
-        # Check for the existence of the requirejs:precompile:all top-level Rake task and disable asset pipeline
-        # compression to ensure that `r.js` gets uncompressed assets.
+        # Check for the `requirejs:precompile:all` top-level Rake task and run the following initialization code.
         Rake.application.top_level_tasks.each do |task_name|
           case task_name
             when "requirejs:precompile:all"
-              config.assets.js_compressor = false
+              # Enable class reloading so that Sprockets doesn't freeze the assets environment. This allows settings
+              # for JS compression to be changes on a per-file basis.
+              config.cache_classes = false
           end
         end if defined?(Rake.application)
 

lib/tasks/requirejs-rails_tasks.rake

@@ -94,6 +94,14 @@ OS X Homebrew users can use 'brew install node'.
 
       requirejs.config.source_dir.mkpath
 
+      # Save the original JS compressor and cache, which will be restored later.
+
+      original_js_compressor = requirejs.env.js_compressor
+      requirejs.env.js_compressor = false
+
+      original_cache = requirejs.env.cache
+      requirejs.env.cache = nil
+
       requirejs.env.each_logical_path do |logical_path|
         m = bower_json_pattern.match(logical_path)
         bower_logical_path = m && "#{m[1]}#{js_ext}"
@@ -104,12 +112,16 @@ OS X Homebrew users can use 'brew install node'.
         asset = requirejs.env.find_asset(logical_path)
 
         if asset
-          # If a `bower.json` was found, then substitute the logical path for the parsed module name.
+          # If a `bower.json` was found, then substitute the logical path with the parsed module name.
           filename = requirejs.config.source_dir.join(bower_logical_path || asset.logical_path)
           filename.dirname.mkpath
           asset.write_to(filename)
         end
       end
+
+      # Restore the original JS compressor and cache.
+      requirejs.env.js_compressor = original_js_compressor
+      requirejs.env.cache = original_cache
     end
 
     task generate_rjs_driver: ["requirejs:setup"] do