Initial, working version

lib/sprockets/umodule.rb

@@ -0,0 +1,15 @@
+require 'sprockets/umodule/version'
+require 'sprockets/umodule/wrapper'
+require 'sprockets/engines'
+
+module Sprockets
+  module Umodule
+    class << self
+      attr_accessor :options
+    end
+
+    @options = {}
+  end
+
+  register_engine '.umodule', Umodule::Wrapper
+end

lib/sprockets/umodule/umodule.js.erb

@@ -0,0 +1,7 @@
+(function () {
+  define = require('module').define;
+
+  define('<%= module_name %>', function (exports, require, module) {
+    <%= source %>
+  });
+})();

lib/sprockets/umodule/version.rb

@@ -0,0 +1,5 @@
+module Sprockets
+  module Umodule
+    VERSION = '1.0.0'
+  end
+end

lib/sprockets/umodule/wrapper.rb

@@ -0,0 +1,47 @@
+require 'tilt'
+
+module Sprockets
+  module Umodule
+    class Wrapper < Tilt::Template
+      @wrapper_template = File.read(File.join(File.dirname(__FILE__), 'umodule.js.erb'))
+
+      class << self
+        attr_reader :wrapper_template
+
+        def engine_initialized?
+          defined?(ERB)
+        end
+      end
+
+      def initialize_engine
+        require 'erb'
+      end
+
+      def prepare
+        @erb = ERB.new(wrapper_template)
+      end
+
+      def evaluate(context, locals, &block)
+        bind(@erb).render(context.logical_path, data)
+      end
+
+      private
+
+      def wrapper_template
+        self.class.wrapper_template
+      end
+
+      def bind(erb)
+        Class.new do
+          def initialize(erb)
+            @erb = erb
+          end
+
+          def render(module_name, source)
+            @erb.result(binding)
+          end
+        end.new(erb)
+      end
+    end
+  end
+end