         src: '**/*.coffee'     # traverse *.coffee files relative to cwd
         dest: 'build/demo/js'  # destination for compiled js files
         ext: '.js'             # file extension for compiled files
+        filter: hasChanged("coffee.demo")
         options:
           sourceMap : true
 

module.exports = (grunt) ->
  grunt.initConfig

    copy:
      template:
        files: [

          src: ['*.less'],     # actual pattern(s) to match
          dest: 'build/css',   # destination path prefix
          ext: '.css',         # dest filepaths will have this extension
          filter: hasChanged("less.development.files.0")
        }]

    coffee:
      compile:
        expand: true           # enable dynamic expansion
        cwd: 'src/coffee'      # source dir for coffee files
        src: '**/*.coffee'     # traverse *.coffee files relative to cwd
        dest: 'build/js'       # destination for compiled js files
        ext: '.js'             # file extension for compiled files
        filter: hasChanged("coffee.compile")
        options:
          sourceMap : true
      test:
