Base 64 encode Sass script

script.rb

# Additional SASS Script functions
require 'sass'
require 'base64'

module Sass::Script::Functions
  def base64encode(string)
    assert_type string, :String
    file = "."+string.value
    data = File.open(file, "rb") {|io| io.read}
    data = [data].flatten.pack("m").gsub("\n","")
    Sass::Script::String.new("'data:#{mime_type(string,nil)};base64,#{data}'")
  end
  declare :base64encode, :args => [:string]
end

private
  def mime_type(path, mime_type = nil)
    return mime_type if mime_type
    path = "#{path}"
    if path.include?('.png')
      'image/png'
    elsif path.include?('.jp')
      'image/jpeg'
    elsif path.include?('.gif')
      'image/gif'
    elsif path.include?('.svg')
      'image/svg+xml'
    elsif path.include?('.otf')
      'font/opentype'
    elsif path.include?('.eot')
      'application/vnd.ms-fontobject'
    elsif path.include?('.ttf')
      'font/truetype'
    elsif path.include?('.woff')
      'application/x-font-woff'
    elsif path.include?('.off')
      'font/openfont'
    elsif path.include?(/\.([a-zA-Z]+)$/)
      "image/#{Regexp.last_match(1).downcase}"
    else
      raise "A mime type could not be determined for #{path}, please specify one explicitly."
    end
  end