module ActiveSupport::Testing::FileFixtures

def file_fixture(fixture_name)

Raises +ArgumentError+ if +fixture_name+ can't be found.

Returns a +Pathname+ to the fixture file named +fixture_name+. 
def file_fixture(fixture_name)
  path = Pathname.new(File.join(file_fixture_path, fixture_name))
  if path.exist?
    path
  else
    msg = "the directory '%s' does not contain a file named '%s'"
    raise ArgumentError, msg % [file_fixture_path, fixture_name]
  end
end