The monkey patch to apply default parameters/default_url_options in RSpec (Rails 4 only)

default_params.rb

# https://github.com/rspec/rspec-rails/issues/255
require 'active_support/concern'

module DefaultParams
  extend ActiveSupport::Concern

  included do
    let(:default_params) { {locale: I18n.locale} }

    def process_with_default_params(action, http_method = 'GET', *args)
      parameters = args.shift

      parameters = default_params.merge(parameters || {})
      args.unshift(parameters)

      process_without_default_params(action, http_method, *args)
    end

    alias_method_chain :process, :default_params
  end
end

RSpec.configure do |config|
  config.include(DefaultParams, :type => :controller)
end