Determine all transitive dependencies of a gem using Bundler

bundle_lock_deps.rb

def bundle_lock_deps(gem_name)
  # reads Gemfile.lock resolved dependencies and return them in an Array of [name, version] pairs
  # requires bundler
  delete_gemfiles
  write_gem_to_gemfile(gem_name)

  raise "bundle lock errored" unless system("bundle lock > /dev/null")
  # read Gemfile.lock and return an Array of gem names
  parser = Bundler::LockfileParser.new(Bundler.read_file('Gemfile.lock'))
  output = []
  parser.specs.each do |item|
    item = item.to_s
    name = item.split(' ')[0]
    version = item.split(' ')[1].tr!('()', '')
    output << [name, version]
  end
  delete_gemfiles
  output
end