coffee-require-browserify.rb

#!/usr/bin/env ruby

require 'fileutils'

# setup
root_dir = ARGV[0] || "#{ENV['HOME']}/Desktop/coffee-to-browserify"
src = "#{root_dir}/src"
dst = "#{root_dir}/dst"

FileUtils.mkdir_p dst

raise "#{src}/src does not exist" unless Dir.exists?(src)
raise "#{dst} does not exist" unless Dir.exists?(dst)

# read all coffeescript files
Dir.chdir(root_dir) do
  coffeescript_files = Dir.glob("./src/**/*.coffee")

  puts "Parsing #{coffeescript_files.length} files..."

  errors = []

  coffeescript_files.each_with_index do |path, j|
    puts "parsing #{path}"
    top_lines = []
    bottom_lines = []
    begin
      File.open(path) do |f|
        # get stuff up to the first "->"
        top_lines_done = false
        f.each_line do |line|
          if top_lines_done
            bottom_lines << line
          else
            top_lines << line
            if line.include?('->')
              if extra = line.split('->')[1]
                # add it below
                bottom_lines << extra
              end
              top_lines_done = true
            end
          end
        end
      end
      # move all onto one line, ensuring separated by no more than one space
      top = top_lines.map(&:strip).join(' ').split("\n").join(' ').gsub(/\s+/, ' ').gsub(',', '')
      # split dependencies and vars into arrays
      dependencies = /\[(.*)\]/.match(top)[1].gsub(/\"|\'/, '').split(' ')
      vars = /\((.*)\)/.match(top)[1].split(' ')
      # rewrite top, browserify style
      lines = []
      dependencies.each_with_index do |dep, i|
        if vars[i]
          lines << "#{vars[i]} = require('#{dep}')"
        else
          # require it but do not assign to a var
          lines << "require('#{dep}')"
        end
      end

      # shift bottom lines X spaces to the left - start with a big number
      spaces = 10000
      last_left_aligned = 0
      bottom_lines.each_with_index do |line, k|
        next if line.strip.empty?
        leading_spaces = line[/\A */].size
        if spaces > leading_spaces
          # set it
          spaces = leading_spaces
          # store this index - we will use it for module export
          last_left_aligned = k
        elsif spaces == leading_spaces
          last_left_aligned = k
        end
      end

      mod_def = bottom_lines[last_left_aligned]
      if mod_def.include?('=')
        mod_def = mod_def.split('=')[0].strip
      else
        mod_def = '_MODULE_'
        bottom_lines[last_left_aligned] = "#{' ' * spaces}#{mod_def} = #{bottom_lines[last_left_aligned].lstrip}"
      end
      bottom_lines += [
        "",
        "",
        "module.exports(#{mod_def})"
      ]

      lines += bottom_lines.map { |line| line.gsub(/\A\ {#{spaces}}/, '').rstrip }

      parsed = path.split('/src/').join('/dst/')
      FileUtils.mkdir_p(parsed.split('/')[0..-2].join('/'))
      File.open(parsed, "w+") do |f|
        f.puts(lines)
      end
    rescue => error
      errors << "COULD NOT PARSE #{path} -- #{error}"
    end
  end
  puts errors.join "\n"
end