你如何重构像这样的长 ruby 方法签名

Question

如何清理这个 ruby 方法签名？

def card(title: nil, textured: nil, threed: true,
         borderless: false, bodyless: false, title_classes: ['card-header'])

问题是我收到 linting/rubocop 警告：

Metrics/ParameterLists: Avoid parameter lists longer than 5 parameters. [6/5]

我的方法有这么多关键字参数的原因是，我使该方法非常灵活。它很强大。

Answer 1

尝试使用这些属性创建案例 class/data class。

class CardProperties
  attr_accessor :title, :textured, :threed, :borderless, :bodyless, :title_classes
end

创建一个新的CardProperties并将其传递给卡片方法：

card_properties = CardProperties.new
card_properties.title = ''
....

card(card_properties)

Answer 2

嗯，理论上您可以使用关键字参数和 Hash#fetch 来处理默认值：

def card(**params)
  title = params.fetch(:title, nil)
  textured = params.fetch(:textured, nil)
  threed = params.fetch(:threed, true)
  borderless = params.fetch(:borderless, false)
  bodyless = params.fetch(:bodyless, false)
  title_classes = params.fetch(:title_classes, ['card-header'])
  ...

但我个人的建议是让 rubocop 闭嘴：

# rubocop:disable Metrics/ParameterLists
def card(...)
  ...
end   
# rubocop:enable Metrics/ParameterLists

Answer 3

做rails做的事

  # Creates a number field.
  #
  # ==== Options
  # * <tt>:min</tt> - The minimum acceptable value.
  # * <tt>:max</tt> - The maximum acceptable value.
  # * <tt>:in</tt> - A range specifying the <tt>:min</tt> and
  #   <tt>:max</tt> values.
  # * <tt>:within</tt> - Same as <tt>:in</tt>.
  # * <tt>:step</tt> - The acceptable value granularity.
  # * Otherwise accepts the same options as text_field_tag.
  #
  # ==== Examples
  #   number_field_tag 'quantity'
  #   # => <input id="quantity" name="quantity" type="number" />
  #
  #   number_field_tag 'quantity', '1'
  #   # => <input id="quantity" name="quantity" type="number" value="1" />
  #
  #   number_field_tag 'quantity', nil, class: 'special_input'
  #   # => <input class="special_input" id="quantity" name="quantity" type="number" />
  #
  #   number_field_tag 'quantity', nil, min: 1
  #   # => <input id="quantity" name="quantity" min="1" type="number" />
  #
  #   number_field_tag 'quantity', nil, max: 9
  #   # => <input id="quantity" name="quantity" max="9" type="number" />
  #
  #   number_field_tag 'quantity', nil, in: 1...10
  #   # => <input id="quantity" name="quantity" min="1" max="9" type="number" />
  #
  #   number_field_tag 'quantity', nil, within: 1...10
  #   # => <input id="quantity" name="quantity" min="1" max="9" type="number" />
  #
  #   number_field_tag 'quantity', nil, min: 1, max: 10
  #   # => <input id="quantity" name="quantity" min="1" max="10" type="number" />
  #
  #   number_field_tag 'quantity', nil, min: 1, max: 10, step: 2
  #   # => <input id="quantity" name="quantity" min="1" max="10" step="2" type="number" />
  #
  #   number_field_tag 'quantity', '1', class: 'special_input', disabled: true
  #   # => <input disabled="disabled" class="special_input" id="quantity" name="quantity" type="number" value="1" />
  def number_field_tag(name, value = nil, options = {})
    options = options.stringify_keys
    options["type"] ||= "number"
    if range = options.delete("in") || options.delete("within")
      options.update("min" => range.min, "max" => range.max)
    end
    text_field_tag(name, value, options)
  end

你如何重构像这样的长 ruby 方法签名

How do you refactor long ruby method signatures like this one

ruby

refactoring

keyword-argument

rubocop