irb_require_global_gem_without_bundler.rb

# Loads the specified gem from RVM's current @global gemset if using
# Bundler and not included in the current Gemfile. Falls back
# accordingly if not using Bundler or RVM.
#
# @note Doesn't load gems not loaded by Bundler if using Bundler and
#   not using RVM, or if gem is located somewhere other than the
#   @global gemset.
# @param [String] The gem to require
# @raise [LoadError] If the gem couldn't be loaded
# Adapted from <https://gist.github.com/794915>
def require_global_gem_without_bundler(gem)
  if defined? ::Bundler
    # Check if the gem has already been loaded by Bundler
    unless Bundler.require.map { |i| i.name }.include? gem
      if global_gem_dir = $LOAD_PATH.grep(/@global.*?lib/).first
        global_gem_dir = global_gem_dir.gsub %r{@global/gems/.*$}, '@global/gems'
        Dir["#{global_gem_dir}/*"].to_a.each do |gem_path|
          if File.basename(gem_path).gsub(/-(\d\.?)+$/, '') == gem
            $LOAD_PATH << "#{gem_path}/lib"
            require gem
            return
          end
        end
      end
      # Either RVM's @global gemset isn't available, or the gem isn't
      #   installed in it, either way, gem wasn't be loaded.
      raise LoadError
    end
  else
    # Bundler isn't being used, load gem normally
    require gem
  end
end