Ruby on rails 4 Rspec 3-如何在模型试验中验证前处理

在我的模型中，我采用了一种前验证方法：

class Post < ActiveRecord::Base
 before_validation :generate_url
 ...

 private

def generate_url
   return unless self.url.blank?
   year = self.published_at.class == ActiveSupport::TimeWithZone ? self.published_at.year : DateTime.now.year
   self.url = "#{year}/#{self.title.parameterize}"
end

spec/factories/post.rb

FactoryGirl.define do
  factory :post do
    user_id 1
    title "myTitle"
    content "myContent."
    published false
    published_at "2014-09-16 08:46:38"
  end
end
# note : attribute url is generated with before_validation

---

让它在验证之前跳过

：

RSpec.describe Post, :type => :model do

  before{ Post.skip_callback(:validation, :before, :generate_url) }

  it { is_expected.to validate_presence_of(:user_id) }
  it { is_expected.to validate_presence_of(:title) }
  it { is_expected.to ensure_length_of(:title).is_at_least(5) }
  it { is_expected.to validate_presence_of(:content) }
  it { is_expected.to ensure_length_of(:content).is_at_least(10) }
  it { is_expected.to validate_presence_of(:url) }
  it { is_expected.to validate_uniqueness_of(:url) }
  it { is_expected.to validate_presence_of(:published_at) }
end

您还可以提供一个块，以便只跳过该块的验证，如下所示：

RSpec.describe Post, :type => :model do

  Post.skip_callback(:validation, :before, :generate_url) do 
    it { is_expected.to validate_presence_of(:user_id) }
    it { is_expected.to validate_presence_of(:title) }
    it { is_expected.to ensure_length_of(:title).is_at_least(5) }
    it { is_expected.to validate_presence_of(:content) }
    it { is_expected.to ensure_length_of(:content).is_at_least(10) }
    it { is_expected.to validate_presence_of(:url) }
    it { is_expected.to validate_uniqueness_of(:url) }
    it { is_expected.to validate_presence_of(:published_at) }
  end
end

注意：self不是零。self.title为零

根据规范，可以通过设置这样一个适当的主题来修复规范

RSpec.describe Post, :type => :model do
  subject { FactoryGirl.create :post }
  it { is_expected.to validate_presence_of(:title) }
end

然而，我尝试了这一点，错误仍然发生
validate\u presence\u of
只需忽略主题并将其重置为
Post.new
。它总是忽略预期的事情。我会说这是一个应该的错误。稍后我会检查他们的代码，或者至少提交问题

同时，不要像以前学校那样做

RSpec.describe Post, :type => :model do
    describe #valiadations do
      let!(:post) {Post.new.tap{|p|p.valid?} }
      it "validated title" do
        expect(post.errors_on[:title.size]).to eq(1) 
      end 
    end
 end

发布生成url方法代码并完成详细答案的测试代码。您必须生成stub_url或向帖子提供一些默认数据，使generate_url正常工作。使用factories/post.rb向帖子提供数据，除非我错过了在规范处理过程中正确读取它的任何附加设置？
RSpec.describe Post, :type => :model do
  subject { FactoryGirl.create :post }
  it { is_expected.to validate_presence_of(:title) }
end

RSpec.describe Post, :type => :model do
    describe #valiadations do
      let!(:post) {Post.new.tap{|p|p.valid?} }
      it "validated title" do
        expect(post.errors_on[:title.size]).to eq(1) 
      end 
    end
 end