Implement UglifyJS support. Closes rstacruz#18.

README.md

@@ -136,7 +136,7 @@ compressors in the `assets` block:
 
 ``` ruby
 assets {
-  js_compression  :jsmin    # :jsmin | :yui | :closure
+  js_compression  :jsmin    # :jsmin | :yui | :closure | :uglify
   css_compression :simple   # :simple | :sass | :yui | :sqwish
 }
 ```
@@ -196,6 +196,33 @@ assets {
 }
 ```
 
+### UglifyJS compression
+
+This uses the [UglifyJS](https://github.com/mishoo/UglifyJS) compressor to 
+compress your JavaScript. You will need to install the 
+[uglifier](http://rubygems.org/gems/uglifier) gem.
+
+For options, refer to the [Uglifier 
+documentation](https://github.com/lautis/uglifier).
+
+``` ruby
+assets {
+  js_compression :uglify
+  js_compression :uglify, [options]
+}
+```
+
+#### Gem
+This depends on the `uglifier` gem. In your Gemfile, you will need to add it.
+For Heroku support, you will need to add the `therubyracer-heroku` gem as well.
+
+``` ruby
+# Gemfile
+gem 'uglifier'
+gem "therubyracer-heroku", "0.8.1.pre3", require: false
+```
+
+
 Images
 ------
 

examples/basic/app.rb

@@ -8,7 +8,8 @@ class App < Sinatra::Base
   register Sinatra::AssetPack
 
   assets do
-    js_compression :closure
+    #js_compression :closure
+    js_compression :uglify
 
     js :main, '/js/main.js', [
       '/js/vendor/*.js',

lib/sinatra/assetpack/compressor.rb

@@ -13,7 +13,7 @@ def compress(str, type, engine=nil, options={})
 
         # Ensure that the engine exists.
         klass = compressors[[type, engine]]
-        raise Error, "Registered engine #{engine} (#{type}) doesn't have an engine class." unless klass
+        raise Error, "Engine #{engine} (#{type}) doesn't exist."  unless klass
 
         # Ensure that the engine can support that type.
         engine = klass.new
@@ -49,5 +49,6 @@ def register(type, engine, meth)
     require "#{AssetPack::PREFIX}/assetpack/engines/sass"
     require "#{AssetPack::PREFIX}/assetpack/engines/sqwish"
     require "#{AssetPack::PREFIX}/assetpack/engines/closure"
+    require "#{AssetPack::PREFIX}/assetpack/engines/uglify"
   end
 end

lib/sinatra/assetpack/engines/uglify.rb

@@ -0,0 +1,12 @@
+module Sinatra::AssetPack
+  class UglifyEngine < Engine
+    def js(str, options={})
+      require 'uglifier'
+      Uglifier.compile str, options
+    rescue => e
+      nil
+    end
+  end
+
+  Compressor.register :js, :uglify, UglifyEngine
+end

sinatra-assetpack.gemspec

@@ -22,4 +22,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency "contest"
   s.add_development_dependency "mocha"
   s.add_development_dependency "stylus"
+  s.add_development_dependency "uglifier"
 end

test/app/app/js/ugly.js

@@ -0,0 +1,7 @@
+(function() {
+  var kitsch = 1;
+  var noodle = 2;
+  var banana = 3;
+  console.log(noodle, banana);
+})();
+

test/uglifier_test.rb

@@ -0,0 +1,23 @@
+require File.expand_path('../test_helper', __FILE__)
+
+class UglifyTest < UnitTest
+  class App < UnitTest::App
+    register Sinatra::AssetPack
+
+    assets do
+      js_compression :uglify, :mangle => true
+      js :main, '/main.js', [
+        '/js/ugly.js'
+      ]
+    end
+  end
+
+  def app
+    App
+  end
+
+  test "build" do
+    get '/main.js'
+    assert !body.include?("noodle")
+  end
+end