use mocha mocking instead of punching ducks

lib/jasmine/headless/task.rb

@@ -44,6 +44,7 @@ module Jasmine
         end
         create_rails_compliant_task if defined?(Rails)
       end
+
       private
       def create_rails_compliant_task
         if Rails.version >= "3.1.0"

spec/lib/jasmine/headless/task_spec.rb

@@ -1,21 +1,19 @@
 require 'spec_helper'
 require 'fakefs/spec_helpers'
 require 'jasmine/headless/task'
-
+require 'mocha'
-module Jasmine
-  module Headless
-    class Task
-      def desc(block); end
-      def task(block); end
-    end
-  end
-end
 
 describe Jasmine::Headless::Task do
   after do
     Object.send(:remove_const, :Rails) if defined?(Rails)
   end
 
+  describe 'define task' do
+    before do
+      Jasmine::Headless::Task.any_instance.stubs(:desc)
+      Jasmine::Headless::Task.any_instance.stubs(:task)
+    end
+
     context 'without Rails' do
       it 'should not explode when Rails is undefined' do
         Jasmine::Headless::Task.new('jasmine:headless')
@@ -35,5 +33,6 @@ describe Jasmine::Headless::Task do
         Jasmine::Headless::Task.new('jasmine:headless')
       end
     end
+  end
 end