module RSpec

def self.const_missing(name)
  # Load rspec-expectations when RSpec::Matchers is referenced. This allows
  # people to define custom matchers (using `RSpec::Matchers.define`) before
  # rspec-core has loaded rspec-expectations (since it delays the loading of
  # it to allow users to configure a different assertion/expectation
  # framework). `autoload` can't be used since it works with ruby's built-in
  # require (e.g. for files that are available relative to a load path dir),
  # but not with rubygems' extended require.
  #
  # As of rspec 2.14.1, we no longer require `rspec/mocks` and
  # `rspec/expectations` when `rspec` is required, so we want
  # to make them available as an autoload.
  require MODULES_TO_AUTOLOAD.fetch(name) { return super }
  ::RSpec.const_get(name)
end