Running multiple cucumber tests in parallel

cucumber.thor

require 'rubygems'
require 'thor'
require 'parallel'
require 'cucumber'
require 'cucumber/cli/main'
require File.expand_path('./lib/thor/json_formatter')
require "bundler"
begin
  Bundler.setup
rescue
  Kernel.exit(1)
end

class Cucumber < Thor


  desc "run", "Run cucumber scenarios"
  method_options %w(browser -b)    => "firefox"
  method_options %w(pretty -p)     => "pretty"
  method_options %w(javascript -j) => true

  def run
    opts = {
      "format" => "json"
    }.merge! options
    
    if opts["browser"] =~ /,/
      browsers = opts["browser"]
      timestamp = Time.now.strftime("%Y%m%d%H%M%S")
      FileUtils.mkdir_p "tmp/#{timestamp}"

      Parallel.map(browsers.split(','), :in_processes => 8) do |browser|
        opts["browser"] = browser
        output = File.expand_path "./tmp/#{timestamp}/#{browser}.json"
        Cucumber::Cli::Main.new(build_command.split(' '), output).execute!

      end

      browsers.split(',').each do |browser|
        json = JSON.parse File.read("tmp/#{timestamp}/#{browser}.json")
        title = "Results for: #{browser} browser"
        puts title
        puts "-" * title.length
        JSONFormatter::format_json json
        puts "-" * title.length
      end
    else
      opts["format"] = "pretty"
      Cucumber::Cli::Main.execute(build_command)
    end
  end

  private

    def build_command(opts)
      [
        "features",
        parse_options(opts)
      ].join(' ')
    end

    def parse_options(opts)
      "--format #{opts["format"]} " + 
      "browser=#{opts["browser"]} " + 
      "javascript=#{opts["javascript"]}"
    end
end