gistfile1.rb

module Foo
  class Bar
    include ActionController::UrlWriter

    def self.some_path
      puts root_path
    end
  end
end

require File.expand_path(File.dirname(__FILE__) + '/../spec/spec_helper')
describe Foo::Bar do
  it "should be able to use url writer" do
    Foo::Bar.some_path.should == '/'
  end
end

## Running spec from command line:
>: spec lib/test.rb 
F

1)
NameError in 'Foo::Bar should be able to use url writer'
undefined local variable or method `root_path' for Foo::Bar:Class
./lib/test.rb:6:in `some_path'
./lib/test.rb:14:
script/spec:10:

Finished in 0.083218 seconds

1 example, 1 failure

## Running in the console:
>: ./script/console 
Loading development environment (Rails 2.3.2)
>> module Foo
>>   class Bar
>>     include ActionController::UrlWriter
>> 
?>     def self.some_path
>>       puts root_path
>>     end
>>   end
>> end
=> nil
>> Foo::Bar.some_path
NameError: undefined local variable or method `root_path' for Foo::Bar:Class
        from (irb):6:in `some_path'
        from (irb):10