Change references from gems to local libraries

degeminator.rb

require 'fileutils'
require 'json'

# change require 'library' to require_relative 'path'
# path will be dynamic depending on the current file path

# I don't deal with libraries I don't know
LIBS_DIR = 'libs'

def generate_require_relative(file_path, require_path)
  # for each dir in file path add ..
  dir_up = File.join(File.dirname(file_path).split(File::SEPARATOR).map{|_| '..'})
  return "require_relative '#{File.join(dir_up, LIBS_DIR, require_path)}'\n"
end

FileUtils.mkdir_p(LIBS_DIR)

apps_dir = ARGV[0]
config_file = ARGV[1]

# check args
if config_file.nil?
  fail "Args not provided. Usage: #{__FILE__} <app directory> <config>"
end

# parse config
config = JSON.parse(IO.read(config_file))

# generate a list of regexps for each lib
require_regexps = config.keys.map do |k|
  {
    regexp: /\s*require\s+['"]#{k}['"]\s*/,
    key: k
  }
end

# go recursively through all the ruby files in apps
apps_files = Dir.glob(File.join(apps_dir, "**/*.rb"))

# and also in libs - interdependencies
lib_files = Dir.glob(File.join(LIBS_DIR, "**/*.rb"))

(apps_files + lib_files).each do |f|
  # line by line
  lines = IO.readlines(f).map do |line|
    new_line = line
    require_regexps.each do |r|
      # if it matches one of the regexps, replace it
      if line =~ r[:regexp]
        # not nice
        new_line = generate_require_relative(f, config[r[:key]])
        puts "Changing #{line} to #{new_line} in #{f}"
        break
      end
    end

    new_line
  end

  File.open(f, 'w') {|file| file.puts lines}
end