replace-opacity.rb

require "pathname"

Dir["app/assets/stylesheets/**/*"].each do |path|
  pathname = Pathname.new(path)
  basename = pathname.basename
  extname  = pathname.extname

  next if     pathname.directory?
  next unless extname.to_s == ".scss"
  next if     basename.to_s.start_with?("_")

  count     = 0
  converted = []

  File.open(path).each_with_index do |line, index|
    if line =~ /^(\s*)opacity:\s*([0-9.]+);\s*$/
      indent = $1
      value  = $2

      converted << "#{indent}@include opacity(#{value});\n"

      count += 1
    else
      converted << line
    end
  end

  if count > 0
    puts "%s: %d replaced" % [path, count]

    file = File.open(path, "w")
    file.write(converted.join)
    file.close
  end
end