require 'formula' class SnowLeopardOrNewer < Requirement def satisfied? MacOS.version >= :snow_leopard end def message "PhantomJS requires Mac OS X 10.6 (Snow Leopard) or newer." end end class Phantomjs < Formula homepage 'http://www.phantomjs.org/' url 'http://phantomjs.googlecode.com/files/phantomjs-1.6.1-macosx-static.zip' sha1 '69a616fa035a815f05e1892e3ff795ef740f568b' depends_on SnowLeopardOrNewer.new def install bin.install 'bin/phantomjs' end end