I've added a new patch at Lighthouse: #203 Added fragment_exist? method - Ruby on Rails - rails
It adds a fragment_exist? method in addition to (read_fragment and write_fragment). This is most useful when using file_store cause You reduce the IO operations and it's better then doing:
read_fragment(path).nil?
To this work properly, I also added an exist? method in all cache stores.
Tests are included. =)
