class ActiveStorage::Filename

def extension_without_delimiter

ActiveStorage::Filename.new(".gitignore").extension_without_delimiter # => ""
ActiveStorage::Filename.new("racecar").extension_without_delimiter # => ""
ActiveStorage::Filename.new("racecar.jpg").extension_without_delimiter # => "jpg"

the beginning). If the filename has no extension, an empty string is returned.
Returns the extension of the filename (i.e. the substring following the last dot, excluding a dot at 
def extension_without_delimiter
  extension_with_delimiter.from(1).to_s
end