rspec - 如果在描述 block 中调用，为什么工厂女孩会创建重复项

Question

我正在使用 Factory Girl 和 Faker 来创建独特的测试用户。
用户模型对电子邮件进行了唯一性验证。

如果我嵌套 2 个级别的 describe 块，那么一些测试将失败，因为有重复的电子邮件。
如果我不嵌套描述块，那么所有工厂调用都会返回唯一的用户并且测试通过。

为什么Faker在第一种情况下会生成重复的邮件？

#factories/user.rb

# a simple factory with Faker
FactoryGirl.define do
  factory :student, class: User do
    first_name { Faker::Name.first_name }
    last_name { Faker::Name.last_name }
    password { Faker::Lorem.words(3).join }
    email { Faker::Internet.email }
  end
end

#spec/models/user_spec.rb   

# in this test structure, Faker returns duplicate emails
describe "nested describe blocks" do
  describe "block 1" do
    it "creates faker duplicates" do 
      10.times{
        FactoryGirl.create(:student)
      }
    end
   end
  describe "block 2" do 
    it "creates faker duplicates" do 
      10.times{
        FactoryGirl.create(:student)
      }
    end
  end
end

# in this structure, Faker emails are unique
describe "no nested describe blocks" do     
  it "doesn't create duplicates" do 
    10.times{
      FactoryGirl.create(:student)
    }
  end      
  it "doesn't create duplicates" do
    10.times{
      FactoryGirl.create(:student)
    }
  end      
end

Rspec 返回以下错误:

Failure/Error: FactoryGirl.create(:student)
 ActiveRecord::RecordInvalid:
   Validation failed: Email has already been taken, Email has already been taken, Authentication token has already been taken

Answer 1

把我的头撞在 table 上几个小时后，我的同事找到了答案:

Why isn't factory_girl operating transactionally for me? - rows remain in database after tests

结果证明这些工厂不是交易性的。在spec_helper.rb 的以下行之后，问题消失了:

config.use_transactional_fixtures = true