Kinda hacky way of specifying that permitted parameters must be present in Rails' strong_parameters - use `insist` in place of `permit`.

strong_requirements.rb

module ActionController
  class Parameters
    def insist(*filters)
      filters.each { |f| ensure_presence(f) }
      permit(filters)
    end

    private
      def ensure_presence(filter, params = self)
        case filter
        when Symbol, String
          raise ParameterMissing.new(filter) unless params.include? filter.to_s
        when Hash
          key = filter.keys.first
          ensure_presence(key, params)
          ensure_presence(filter.values, params[key])
        when Array
          filter.each { |f| ensure_presence(f, params) }
        end
      end
  end
end