RSpec 示例不适用于 before_validation

Question

我保存了一个相当简单的模型，但遇到了 RSpec 失败，我找不到解决方案。我也在使用 shoulda gem。

CharacterSheet 模型：

class CharacterSheet < ActiveRecord::Base
  validates :character_name, :player_name, :strength, :strength_modifier, presence: true

  before_validation :calculate_strength_modifier, on: :create

  def calculate_strength_modifier
    self.strength_modifier = ((self.strength - 10)/2).floor
  end

end

RSpec 示例：

RSpec.describe CharacterSheet, type: :model do

  let(:character_sheet) { CharacterSheet.new(character_name: "Test Character",
                                                player_name: "Michael",
                                                   strength: 18) }

  describe "attributes" do

    it { expect(character_sheet).to validate_presence_of :character_name }
    it { expect(character_sheet).to validate_presence_of :player_name }
    it { expect(character_sheet).to validate_presence_of :strength }
    it { expect(character_sheet).to validate_presence_of :strength_modifier }

    it "saves attributes" do
      character_sheet.save!
      expect(character_sheet).to be_valid
    end

  end
end

这些是我遇到的失败：

失败：

  1) CharacterSheet attributes should require strength to be set
     Failure/Error: it { expect(character_sheet).to validate_presence_of :strength }
     NoMethodError:
       undefined method `-' for nil:NilClass

  2) CharacterSheet attributes should require strength_modifier to be set
     Failure/Error: it { expect(character_sheet).to validate_presence_of :strength_modifier }
       Expected errors to include "can't be blank" when strength_modifier is set to nil,
       got no errors

如果我在 Rails 控制台中手动创建记录，它看起来是正确的。只是测试失败了。

此外，如果我删除 before_validation 调用。唯一失败的是预期的“保存属性”示例。

Answer 1

好的，首先您必须了解validate_presence_of 匹配器...将该属性的值设置为nil...并测试您是否遇到错误。

想想这对您的验证前意味着什么。你一无所有...然后在您进行验证之前触发验证前触发器...您尝试从无到有 10 并且它爆炸了。

我敢打赌，你应该在那里进行测试，以确保它不会做傻事。例如：

def calculate_strength_modifier
  self.strength_modifier = ((self.strength - 10)/2).floor if self.strength.present?
end