Javascript parsing benchmark

javascript_parse_benchmark.rb

script = open(ARGV[0]).read

require "benchmark"
include Benchmark

require 'rkelly'
require 'parsejs'
require 'violet'
require 'content_urls'

parser = RKelly::Parser.new

n = 100

Benchmark.benchmark(CAPTION, 12, FORMAT, ">% Change:") do |x|
  t_gsub = x.report("gsub") do
    script.gsub!('window.location','foo.window.location')
    script.gsub!('foo.window.location.replace','ot.window.location_replace')
    script.gsub!('foo.window.location.href','ot.window.location.ot_href')
    script.gsub!('document.location','foo.document_location')
    script.gsub!('foo.document_location.replace', 'foo.document_location_replace')
    script.gsub!('foo.document_location.href','foo.document_location.ot_href')
    script.gsub!('top.location','foo.top_location')
  end
  
  t_parser4 = x.report("content_urls") do
    res = ContentUrls::JavaScriptParser.rewrite_each_url(script) { |url| url.upcase }
  end

  t_parser = x.report("rkelly") do
    ast    = parser.parse( script )
    ast.each do |node|
      node
      # node.value = 'foo.window.location' if node.value == 'window.location'
      # node.name = 'foo.window.location' if node.respond_to?(:name) && node.name == 'window.location'
    end
    ast.to_ecma
  end

  t_parser2 = x.report("parsejs") do
    ast = ParseJS.parse( script )
    ParseJS::Stringifier.to_string(ast)
  end

  t_parser3 = x.report("violet") do
    ast =  Violet::Parser.parse(script)
    ast.to_s
  end

  [( (t_parser4 - t_gsub) / t_gsub ) * 100] unless t_gsub == 0
end