如何在factory_girl中建立/创建多对多关联？

我有一个Person与具有多对多关系的模型Email模型，我想创建一个工厂，让我为该人生成名字和姓氏（这已经完成）并创建一个基于该人姓名的电子邮件地址。这是我要创建的person's name:

Factory.sequence :first_name do |n|
  first_name = %w[FirstName1 FirstName2] # ... etc (I'm using a real subset of first names)
  first_name[(rand * first_name.length)]
end

Factory.sequence :last_name do |n|
  last_name = %w[LastName1 LastName2] # ... etc (I'm using a real subset of last names)
  last_name[(rand * last_name.length)]
end

Factory.define :person do |p|
  #p.id ???
  p.first_name { Factory.next(:first_name) }
  p.last_name { Factory.next(:last_name) }
  #ok here is where I'm stuck
  #p.email_addresses {|p| Factory(:email_address_person_link) }
end

Factory.define :email_address_person_link do |eapl|
  # how can I link this with :person and :email_address ? 
  # eapl.person_id ???
  # eapl.email_address_id ???
end

Factory.define :email_address do |e|
  #how can I pass p.first_name and p.last_name into here?
  #e.id ???
  e.email first_name + "." + last_name + "@test.com"
end

好吧，我想我现在明白你在问什么了。像这样的东西应该有效（未经测试，但我在另一个项目中做了类似的事情）：

Factory.define :person do |f|
  f.first_name 'John'
  f.last_name 'Doe'
end

Factory.define :email do |f|
end

# This is optional for isolating association testing; if you want this 
# everywhere, add the +after_build+ block to the :person factory definition
Factory.define :person_with_email, :parent => :person do |f|
  f.after_build do |p|
    p.emails << Factory(:email, :email => "#{p.first_name}.#{p.last_name}@gmail.com")
    # OR
    # Factory(:email, :person => p, :email => "#{p.first_name}.#{p.last_name}@gmail.com")
  end
end

如前所述，使用第三个独立工厂是可选的。就我而言，我并不总是想为每个测试生成关联，因此我创建了一个单独的工厂，仅在一些特定测试中使用。