container class

container.rb

class Container
  SETTER_METHOD_REGEX = /^(?<name>\w+)=$/.freeze

  def initialize(params = {})
    @registry = {}
    @registry.merge(params.symbolize_keys) if params.present?
  end

  def method_missing(method_name, *args, &block)
    matched = method_name.to_s.match(SETTER_METHOD_REGEX)
    if matched
      @registry[matched[:name].to_sym] = args.first
    else
      if @registry.key?(method_name)
        @registry.fetch(method_name)
      else
        super
      end
    end
  end

  def respond_to_missing?(method_name, include_private = false)
    method_name =~ SETTER_METHOD_REGEX ||
      key?(method_name) ||
      super
  end

  def key?(key)
    @registry.key?(key)
  end
end