Snippet from Gem Garage

dependencies.rb

# Public: Take the gem's runtime dependencies and install them from their remote source
#
# Returns nothing.
# Raises GemGarage::MissingGemError if the gem file doesn't exist.
def install_dependencies
  raise GemGarage::MissingGemError unless File.exists?(file_path)

  with_gem do |spec|
    spec.runtime_dependencies.each do |dependency|
      Resque.enqueue(GemGarage::Jobs::InstallDependency, rubygem.account_id, dependency.name, dependency.requirement)
    end
  end
end