Good catch, this was a mistake, I meant to delete the file:// matcher and use a uri object to validate that and handle http:// and file:// cases.

I personally tested the absolute and relative cases but wasn't sure how I could test them in this situation without breaking the build as the absolute path will change on every system.  Any suggestions?  I chalk this up to "don't test the engine", I trust Ruby's File and Pathname functionality to handle relative and local paths correctly.