Homebrew Formula of yarn installing a test build of my homebrew-node-gyp branch

yarn.rb

class Yarn < Formula
  desc "JavaScript package manager"
  homepage "https://yarnpkg.com/"
  url "https://github.com/chrmoritz/yarn/releases/download/v1.3.2/yarn-v1.3.2.tar.gz"
  sha256 "df9ab3a21ba62ed57fc68c592b4d0000b762739ee4d80566f293187705b6f12b"
  revision 42

  bottle :unneeded

  depends_on "node" => :recommended

  def install
    libexec.install Dir["*"]
    (bin/"yarn").write_env_script "#{libexec}/bin/yarn.js", :PREFIX => HOMEBREW_PREFIX
    (bin/"yarnpkg").write_env_script "#{libexec}/bin/yarn.js", :PREFIX => HOMEBREW_PREFIX
    inreplace "#{libexec}/package.json", '"installationMethod": "tar"', '"installationMethod": "homebrew"'
  end

  test do
    (testpath/"package.json").write('{"name": "test"}')
    system bin/"yarn", "add", "jquery"
  end
end