Automated Xcode installation on pre-release OS X with mas-cli. mas-cli requires Xcode to compile, so this script downloads a binary of mas-cli, uses it just to install Xcode, then uses the newly installed Xcode to compile mas-cli and replace the pre-compiled binary.

mas-bootstrap.rb

#!/usr/bin/env ruby

require "open-uri"
require "json"

RELEASES_URL = "https://api.github.com/repos/argon/mas/releases"
ASSET_NAME = "mas-cli.zip"
EXECUTABLE_NAME = "mas"
XCODE_ID = "497799835"

releases = JSON.parse(open(RELEASES_URL).read)
release = releases.first

Dir.mktmpdir do |tmp_dir|
  asset_path = File.join(tmp_dir, ASSET_NAME)
  asset = release["assets"].find { |a| a["name"] == ASSET_NAME }
  download_url = asset["browser_download_url"]

  File.write asset_path, open(download_url).read
  Dir.chdir(tmp_dir) { system "unzip", "-q", asset_path }
  executable_path = File.join(tmp_dir, EXECUTABLE_NAME)

  email    = (print "Apple ID email: ";    gets.chomp)
  password = (print "Apple ID password: "; gets.chomp)

  system executable_path, "signin", email, password
  system executable_path, "install", XCODE_ID
  system "brew", "install", "--build-from-source", "mas"
end